In defence of the decriminalisation of drug possession in the UK

Authors Alex Stevens, Niamh Eastwood and Kirstie Douse Published March 24, 2024 Abstract In this review article, we develop the case for the decriminalisation of drug possession in the UK by describing our ‘modest proposal’ to repeal the relevant sections of the Misuse of Drugs Act 1971 and its advantages. We defend this proposal against  …

Childhood trauma, challenging experiences, and post traumatic growth in ayahuasca use

Authors Ksenia Cassidy, CJ Healy, Eva Henje and Wendy D’Andrea Published March 20, 2024 Abstract Challenging experiences in ayahuasca use, childhood trauma, and posttraumatic growth have not been investigated systematically. This study aimed to explore whether a self-reported history of childhood trauma was associated with challenging experiences during acute ayahuasca effects and whether such challenging  …

Medicinal cannabis for treating PTSD and comorbid depression: Real World Evidence from Project T21

Authors Michael Lynskey, Alkyoni Athanasiou-Fragkouli, Hannah Thurgur, Anne Schlag and David Nutt Published March 12, 2024 Background Cannabis-based medicinal products (CBMPs) are increasingly being used to treat post-traumatic stress disorder (PTSD), despite limited evidence of their efficacy. PTSD is often comorbid with major depression, and little is known about whether comorbid depression alters the effectiveness  …

Participation in an indigenous Amazonian-led ayahuasca retreat associated with increases in nature relatedness – a pilot study

Authors Simon GD Ruffell, Sam Gandy, WaiFung Tsang, Rono Lopez, Nathan O’Rourke, Arsalan Akhtar, Nige Netzband, Jack Hollingdale, Daniel Perkins and Jerome Sarris Published February 28, 2024 Abstract Indigenous Amazonian shamanic ayahuasca practice is embedded in a nature-based context and is employed as an ecological mediating agent and in collective environmental decision-making processes by some  …

A history of the European Medical Society for Psycholytic Therapy (EPT) 1964–1974

Authors Torsten Passie Published February 22, 2024 Abstract The emergence of a so-called psychedelic renaissance has been proposed to characterize the revival of research into (psycho-)therapies using psychedelic drugs. In Europe, the most widespread approach employed in the 1960s and 1970s that involved the use of drugs like LSD and psilocybin as an adjunct to  …

Will the war on vaping result in more harm?

Key take-home messages: The disposable vape ban is intended to curb youth vaping, addressing the increasing use of vaping among youth in 2022 and 2023. There is a concern that the ban may have unintended and disastrous consequences on people who have successfully quit, or who are transitioning to quit smoking by using disposable vapes.  …

Teaching Children about Vaping

Written by Hannah Dawes  In a world of misinformation, what can we teachers do? What should we do? How to capture the strained attention of a young audience and give them something useful? TikTok makes for gripping viewing. One video shows stock footage of a coffin being lowered into the ground. My friend died of  …

Minorities’ diminished psychedelic returns: Cardio-metabolic health

Authors Sean Matthew Viña Published January 9, 2024 Abstract Although there is a growing support for the protective factor of psychedelics to improve mental and physical health, these effects may differ across racial and ethnic groups. Race differences remain a critically understudied gap in psychedelic literature. Recent empirical research into Minority Diminished Psychedelic Returns suggests  …

How much do you know about medical cannabis?

In November we brought over 200 patients together in London (and many more online) for the second UK Patient Conference, hosted by Drug Science and Medcan Family Foundation, with support from the Cannabis Industry Council. The event took place as part of Medical Cannabis Awareness Week, which marked five years since the landmark law change  …

Results from Long COVID trial published

We are delighted to share the news that the results from the Long COVID trial have been published by the British Journal of Clinical Pharmacology. Access Publication Long COVID, a condition characterised by persistent symptoms following a COVID-19 infection, presents a significant challenge for both patients and healthcare providers. You can read our published review  …

Was ketamine the cause of Matthew Perry’s death?

By Prof David Nutt The death of Matthew Perry from a combination of ketamine and drowning is a sad loss of an exceptional talent. Understandably his fans and the public at large are looking to see how it might have been avoided. Some are blaming ketamine and resurrecting calls for more severe controls on its  …

UK’s largest medical cannabis study announces new industry partners

Drug Science is pleased to welcome three new industry partners to its groundbreaking medical cannabis study, T21 (formerly Project TWENTY21) They are SOMAí Pharmaceuticals, Blackpoint Biotech and 4Clabs who will be joining long-standing partner EthyPharm as collaborators. Launched in 2019, and now over 4000 patients in, T21 is building the scientific evidence base for the  …

Patients with a terminal diagnosis want to access psilocybin in the UK

“I want to live as well as I can, for as long as I can. Because my life may end early but I’m not dead yet!”  In a report published today, patients set out their case for Compassionate Access to Psilocybin in the UK calling for the UK government to redraw its rules around psilocybin  …

Psilocybin for Existential Distress

Compassionate Access to Psilocybin report Read our latest report on why patients experiencing ‘Existential Distress’ ought to be permitted access to psilocybin-assisted psychotherapy Access the full report here By James Bunn Chief Executive Officer – Psilonautica  Psilocybin for existential distress Psilocybin has shown promise as a treatment for existential distress, a condition marked by feelings of hopelessness,  …

Decrypting the cryptomarkets: Trends over a decade of the Dark Web drug trade

Authors Harjeev Kour Sudan, Andy Man Yeung Tai, Jane Kim and Reinhard Michael Krausz Published November 19, 2023 Introduction The Dark Web is a subsection of the Internet only accessible through specific search engines, making it impossible to trace users. Due to extensive anonymity, the drug trade on the Dark Web makes regulation complicated. We  …

Can ayahuasca reduce inattention, hyperactivity and impulsivity? A pilot study

Authors WaiFung Tsang, Simon GD Ruffell, Nigel Netzband, Angelina Jong, James Rucker, Quinton Deeley and Jack Hollingdale Published November 16, 2023 Background The potential benefits of ayahuasca on mental health conditions are well documented. This pilot study is the first to explore whether there is an association with ayahuasca use and reductions in inattention, hyperactivity  …

The impact of over the counter and prescription medication misuse on friends and family

Authors Rosalind Gittins, Roya Vaziri, and Ian Maidment Published November 16, 2023 Introduction Over the counter and prescription-only medication misuse is of concern. Little is known about the impact on friends/family who provide individuals with support. It is important to increase understanding to identify how substance misuse services (SMS) and others can better meet their  …

Today’s ban on 'laughing gas' is wrong - Prof David Nutt

The government’s ban on nitrous oxide comes into force today (Wednesday 8th November, 2023) and possession of the drug is now a criminal act in the United Kingdom. Drug Science’s founder, Professor David Nutt, says: “We believe the ban is wrong. It is completely disproportionate to nitrous oxide’s harms. It will place a new burden  …

Mike Roberts – Medical Cannabis Patient Story

The UK Patient Conference is being held in central London and online, Friday 3 November 2023. It brings together patients, industry, healthcare professionals, charities and members of the public to discuss current issues in the medical cannabis space. Everyone is welcome. Buy a ticket from £5 In the lead up to the event, we are  …

We have launched our new consultancy arm

Founded in 2010 by the neuropsychopharmacologist Professor David Nutt, independent research charity Drug Science is the leading organisation of its kind in the UK — we built a renowned international reputation as thought leaders, particularly around the study of cannabis and psychedelics. Today, we launch Drug Science Consultancy, to provide research advice and consultancy services  …

Sophie Gorman – Medical Cannabis Patient Story

The UK Patient Conference is being held in central London and online, Friday 3 November 2023. It brings together patients, industry, healthcare professionals, charities and members of the public to discuss current issues in the medical cannabis space. Everyone is welcome. Buy a ticket from £5 In the lead up to the event, we are  …

What is Testosterone?

Testosterone is a hormone produced naturally in the body. It is the major sex hormone in males and is produced in smaller quantities in the ovaries and adrenal glands of females.

Testosterone is also available as a prescription medication, belonging to the drug class of anabolic-androgenic steroids. This is a human-made (synthetic) form of testosterone and is designed to bring about the same effect as naturally occurring testosterone.

Some people also use testosterone illicitly, outside of a medical context.

What are the different forms of Testosterone?

Testosterone is available in a few different forms:



These are applied directly to the skin. It is possible for these gels to transfer to other people unintentionally if their skin touches the area which the gel has been applied to. 



Liquid testosterone designed to be injected deep into the gluteal muscle.



Transdermal patches which are applied to the skin. They are usually worn at all times and replaced with a new patch every 24 hours.


Oral tablets & Capsules

Methyltestosterone and testosterone undecanoate available for oral administration and can be used as an alternative to gels for androgen deficiency.  Prescribed to help bone growth in boys being treated for delayed puberty.



Other testosterone products:



Testosterone boosters are supplements which claim to increase levels of testosterone in the body. These are typically precursors to testosterone and are sometimes available in health shops. However, these can vary in quality and there is little scientific evidence to support their use.

How does Testosterone work as a drug in the body and brain?

Testosterone activates androgen receptors in various tissues in the body. This in turn leads to the expression of genes which cause growth and development of male sex organs and secondary sexual characteristics. For example, the thickening of vocal cords, which leads to deepening of the voice.

What are the effects of Testosterone?

Unlike some drugs, the effects of testosterone will not be seen in a matter of minutes or hours. Some effects, such as increased libido, can be seen after 3 weeks of use. However, other effects, such as changes in muscle strength, can take up to 16 weeks to be seen.  


The effects of testosterone include:


  • Development of male sex organs
  • Deepening of the voice
  • Growth of facial and pubic hair
  • Increased muscle size and strength
  • Bone growth and strength
  • Increased libido (sex drive)
  • Increased sperm production
  • Ovarian function
Does Testosterone have any medical uses?

Testosterone and its derivatives have various medical uses. It can be used to treat delayed male puberty and abnormally low production of testosterone. Testosterone therapy can also help with generalised weakness, low energy, disabling frailty, depression, problems with cognition and problems with sexual function.


Another medical use for testosterone is masculinising hormone therapy (or gender affirming therapy) for transgender men and non-binary people. This produces physical changes of secondary sex characteristics, helping to better align the body with gender identity. When used in this context, testosterone also stops the menstrual cycle and decreases oestrogen production in the ovaries.

What are the risks of using Testosterone? Can they be avoided or reduced?

Using testosterone involves some risks. The risks are increased when an artificially high level of testosterone is present in the body which is more likely to occur when testosterone is taken outside of a medical context.


These risks include:

  • Low sperm count
  • Heart damage and increased risk of cardiac arrest
  • Prostate enlargement
  • Liver disease
  • Insomnia
  • High blood pressure
  • High cholesterol
  • Increased risk of blood clots
  • Mood swings


The risk of experiencing these effects can be reduced by only taking the amount of testosterone you are prescribed. Illicit users should limit use to prevent these effects from occurring.

Are there health conditions that make Testosterone more dangerous?

Whilst using testosterone doesn’t increase the risk of developing prostate cancer, it can stimulate the growth of cancerous prostate cells. Therefore, those with prostate cancer or at risk of developing prostate cancer should not take testosterone.


Testosterone and testosterone-based products should not be used in men who have hypercalcemia (raised calcium) or a history of breast or liver cancer.

Can Testosterone be used with other drugs?

If testosterone is taken alongside an adrenocorticotropic hormone or corticosteroids, a build up of fluid (oedema) may occur in the body.

How addictive is Testosterone?

People who regularly use testosterone outside of a medical context are at risk of developing an addiction to the drug, both physical and psychological. Withdrawal symptoms are felt if the person ceases use or lowers the dose that they take.


Medical assistance should be consulted for help with testosterone addiction. Medical professionals can help to find a safe way to stop taking testosterone and help to minimise withdrawal symptoms.

What are the harms of Testosterone addiction and withdrawal?

As with any addiction, addiction to testosterone can lead to problems at work or school and put a strain on personal relationships, alongside the physical and mental health issues that can ensue.  


Withdrawal symptoms include:

  • low libido
  • loss of appetite
  • mood swings
  • insomnia
  • fatigue
  • depression


Some signs that a person may be addicted to testosterone include:

  • Ignoring responsibilities
  • Persistent issues with friends and family
  • Continuing to use testosterone despite negative physical side effects.
  • Spending a lot of time and money in an effort to obtain testosterone.
  • Struggling to cut back on use despite repeated attempts.
Testosterone harm reduction advice

Minimising use, avoiding addiction

Physical dependence to testosterone does not occur immediately, however, the effects produced are often desirable for those who chose to use it. Therefore, they are likely to continue to use testosterone to increase the effects. This results in tolerance developing and a higher dose being required to produce desired effects. If you use testosterone illicitly, try to limit the dose you take and how often you take it.


How are you taking it?

Injecting any substance carries an increased risk of infection. If injecting, use new, sterile equipment. Do not re-use equipment and dispose of needles in a sharps bin. These are available from your local pharmacy and do not require a prescription.


Using an oral or topical form (creams or gels) of testosterone minimises the risk of infection. If using topical steroids, wash hands with soap immediately after use.

What is Flunitrazepam (Rohypnol)?

Flunitrazepam, commonly known by the trade name Rohypnol, is a central nervous system depressant in the benzodiazepine drug class. The sedative effects of flunitrazepam are around 7 to 10 times stronger than those of diazepam (Valium).

Rohypnol is also used illicitly. The drug has been associated with sexual assault cases, in which the drug is given to the victim without their knowing or consent, by addition to their drink. Rohypnol is tasteless and colourless, therefore, the victim may not notice that their drink has been tampered with. This often renders the victim heavily sedated and can cause strong amnesia (loss of short term memory) leading the victim to have little to no recall of the assault. The drug is sometimes referred to as a “date rape” drug.

What are the different forms of Flunitrazepam?

Flunitrazepam itself exists as a white powder that can be made into tablets.


When used illicitly, and with intent to sedate a person without their consent, the tablets are often crushed up and put into (often alcoholic) drinks. In an effort to combat the use of the drug to spike drinks, manufacturers began to add colouring dye to produce olive green tablets that dye liquid blue, making it more noticeable if a drink is spiked with the drug. Not all flunitrazepam tablets contain this dye.


Users who intend to take the drug themselves may also swallow whole tablets, crush them up and snort them and in some cases inject liquid flunitrazepam.

How does Flunitrazepam work as a drug in the body and brain?

Like other benzodiazepines and Z drugs (other sedative-hypnotic drugs such as Zopiclone), flunitrazepam binds to GABAA receptors in the brain. This potentiates the effects of the neurotransmitter GABA (Gamma-Aminobutyric Acid) at these receptors which reduces activity in the brain, especially those which control anxiety, sleep, memory, reasoning, and essential autonomic functions such as breathing and heartbeat.

Does Flunitrazepam have any medical uses?

Due to its powerful sedative effects, flunitrazepam is used in a medical context in Germany, Ireland and Iceland to name a few countries. Here they are used to treat insomnia when other medicines do not work, however, it is not used in the long term for this purpose due to an increase in the risks with sustained use. The drug is also used as a pre-anaesthetic before operations.

What are the effects of Flunitrazepam?

The effects of flunitrazepam can be felt around 15-20 minutes after consumption with these effects lasting for around 4-6 hours and up to 12 hours in some cases.


These effects include:

  • Sedation
  • Muscle relaxation
  • Reduced anxiety
  • Dizziness
  • Loss of motor control
  • Decreased reaction time
  • Slurred speech
  • Confusion
  • Amnesia
  • Aggression
  • Excitability
What are the risks of Flunitrazepam? Can they be avoided or reduced?

Using flunitrazepam poses risks to both physical and mental health.


If someone takes an overdose of flunitrazepam, they can suffer unpleasant and potentially harmful effects. Overdoses can lead to confusion, slurring of speech, sleepiness, loss of coordination and collapse. If someone has taken enough to become unconscious, there is a risk of inhaling and choking on stomach contents which can potentially be fatal and breathing and respiratory rate can slow down or even stop.


The danger of severe harm and death is much greater if flunitrazepam is taken with other sedative drugs such as alcohol, heroin or GHB. In these combinations, respiratory arrest may occur. Respiratory arrest is the absence of breathing. It can result from respiratory distress, respiratory failure, or other events including acute head injury or drowning.


Emergency medical assistance should be sought when someone becomes unresponsive after taking drugs.


To reduce the risk of overdosing on flunitrazepam, carefully monitoring of how much has been consumed is advisable. Starting with a small dose and seeing how you feel can prevent you from taking too much all at once. It is advisable to have someone trustworthy around when taking flunitrazepam so that they can help if negative effects are experienced. It is also possible to buy reagent test kits which can confirm or rule out the presence of flunitrazepam. This can also be useful to test a drink that you suspect may have been spiked with the drug.


Flunitrazepam decreases control and impairs judgment, meaning activities like driving under the influence of flunitrazepam is very dangerous.

Are there health conditions that make Flunitrazepam more dangerous?

The risk of respiratory arrest or reduced breathing rate caused by flunitrazepam are increased in people with conditions such as muscle weakness, sleep apnoea, or lung disease/breathing disorders.


Taking flunitrazepam regularly may put someone at a greater risk of accidents. Doctors in countries where flunitrazepam is prescribed make a considered decision before prescribing it to people with impaired balance and coordination, who are at risk of falling or who may be severely injured if they do.

Taking Flunitrazepam along with other drugs

Taking flunitrazepam with other drugs increases the risks. Most notably, the risk of respiratory arrest/.


Additionally, the effects of flunitrazepam may be masked if taken with a stimulant. This can lead to overdose when the effects of a short acting stimulant, such as cocaine, wear off if the user consumes more flunitrazepam due to not initially being able to feel the effects.

How addictive is Flunitrazepam?

One-off or occasional use of flunitrazepam is unlikely to result in the development of addiction.However, taking flunitrazepam regularly over a sustained period can cause very serious psychological addiction.


Dependency also leads people to experience withdrawal symptoms which include nausea, confusion, headaches, anxiety, and dizziness. Users may crave the drug and feel unable to cope without it. People who regularly use flunitrazepam may become tolerant to the drug’s effects and to the effects of other benzodiazepines/Z drugs, leading them to take increasingly higher doses. The longer the drug is taken and the higher and more regular the dose, the higher the risk of developing dependence and tolerance.

What are the harms of Flunitrazepam addiction and withdrawal?

A period of sustained use of flunitrazepam can be debilitating and prevent people from working and leading an active life. It may also cause mental and physical harm and withdrawal can be very unpleasant.


Long term use of flunitrazepam may be accompanied with the use of other drugs, such as alcohol and opioids. This is because some users may feel that flunitrazepam enhances the effects of another drug, or to lessen the effects of drug withdrawal/comedown, or both.


Acute withdrawal effects include anxiety, increased heart rate and blood pressure, shaking, insomnia and sensitivity to sound/light. Very severe withdrawal can cause symptoms that require intensive care, such as seizures. Someone who has been taking flunitrazepam regularly for a sustained period should only stop under the supervision and guidance of a doctor. Abruptly stopping use can be harmful so it is often better to taper use gradually before stopping entirely. To do this safely, professional advice is recommended.


Potential effects of long-term flunitrazepam use include anxiety, depression, and insomnia. These effects may last for months, depending on how dependent a person was on the drug, the length of time used, untreated on-going psychiatric conditions, as well as other personal factors such as why the drug was initially prescribed or used illicitly.

What are the long term effects of flunitrazepam on health and wellbeing?

There are possible harms of long-term flunitrazepam use, although not everyone experiences problems with long term use. Specific harms that could be caused by long term use include lack of energy, sleep problems, impaired memory, and changes in personality (becoming more aggressive, for example). Long term flunitrazepam use is also associated with anxiety related mental health problems such as panic disorder or social phobia. This may be because long term use causes the brain and body to become reliant on the drug’s anxiety-relieving effects. It may therefore be particularly risky for people with depression/anxiety disorders to take flunitrazepam long term.

Flunitrazepam harm reduction advice

How much are you taking, how often?

The occasional recreational use of flunitrazepam has a relatively low risk of harm. However, flunitrazepam addiction and dependence can develop after a few weeks of use and can cause considerable harm to quality of life and health. If you develop tolerance to any of the effects of flunitrazepam, this should be taken as a warning sign that the drug may be harmfully affecting your body and brain.


Are you taking it with anything else? Mixing drugs is risky.

Drug effects are unpredictable, but mixing drugs makes the effects on your body and mind even harder to control. Deaths involving flunitrazepam generally involve other drugs too. It is particularly dangerous to combine flunitrazepam with another drug that can depress the central nervous system such as alcohol, heroin (or any opioid) or gamma-hydroxybutyrate (GHB). Additionally, if someone is taking antidepressants or even antihistamines, these may increase the effect of the flunitrazepam.

What is Methamphetamine?

Methamphetamine is a stimulant drug of the substituted amphetamine class. The addition of a methyl group gives the drug high lipid solubility, leading to it being more potent and euphoric than amphetamine. Methamphetamine is also known for its long-lasting effects and is considered to have very high abuse potential.

Methamphetamine was first synthesised in 1887 but did not have any known medical use until 1934. It was initially sold as a decongestant. It is now used primarily for treating treatment resistant obesity and ADHD, though it is not used medically in the UK. Methamphetamine was reclassified from class B to class A in 2007, due to fears of increasing prevalence of use.

Other common names include: meth, tina, shard, crystal and ice, among others.

What are the different forms of Methamphetamine?

Methamphetamine comes in a variety of forms and can differ in purity from batch to batch.


Crystal methamphetamine

This is the most common form of illicit methamphetamine seen on the street. It generally appears as medium sized glass-like crystals. It can also look like white/clear crystal powder, and coloured crystals have been reported – though these tend to be artificially coloured using food dye. It can be taken orally (rolled up in cigarette paper and swallowed), snorted, rubbed on the gums, smoked or dissolved in water and injected (both intramuscular and intravenous injection). Smoking and injection are the most likely to result in addiction, as they quickly produce a ‘rush’ of euphoria, though all routes of administration can lead to addiction. Smoking/vaporisation and injection are the most dangerous methods of using the substance, as the euphoria can fade much faster than the other effects of the drug wear off. This can lead to compulsive redosing, amplifying the longer lasting effects.


Methamphetamine freebase

Freebase methamphetamine appears without the associated hydrochloride molecule of the salt form (methamphetamine HCL), just like the difference between cocaine powder (cocaine HCL) and crack cocaine (freebase cocaine).

At room temperature, freebase methamphetamine is a colourless liquid.


Methamphetamine pills

Illicitly produced methamphetamine pills are relatively unlikely to be sold openly advertised as methamphetamine. People who knowingly choose to use methamphetamine tend to be looking for crystal meth, as it allows the drug to be injected or smoked more easily. Sometimes pills sold as MDMA, or other substances, may contain methamphetamine as either the only active ingredient, or one of multiple active ingredients, though this is relatively rare in the UK.


Prescription methamphetamine

Prescription methamphetamine, known as Desoxyn, is manufactured in 5 mg pills. It is not routinely prescribed by the NHS, but may be for cases of ADHD in which methylphenidate (Ritalin), dextroamphetamine and lisdexamphetamine (an amphetamine prodrug) have been unsuccessful. It can be prescribed in America for extreme cases of ADHD and obesity, but is not licensed for use in the UK.

How does Methamphetamine work as a drug in the body and brain?

Methamphetamine is a psychostimulant. This means that it works by increasing activity in certain parts of the nervous system. Specifically, it acts as a releasing agent for serotonin, dopamine and noradrenaline. It also inhibits the reuptake of noradrenaline meaning any released stays in the brain for longer than it otherwise would. These changes increase the levels of extracellular monoamine neurotransmitters. Methamphetamine is an analogue of amphetamine, where the addition of the methyl group increases the solubility in lipids. This allows it to cross the blood brain barrier much faster – leading to greater euphoric effects and faster onset of action compared to amphetamine.

What are the effects of Methamphetamine?

When swallowed, methamphetamine’s effects usually take under an hour to kick in, with the full effects taking up to four hours to develop – though this can be as little as an hour on an empty stomach. This time can be extended further after a particularly large meal. After snorting, methamphetamine usually kicks in after just a few minutes, and smoking or injecting can have effects within seconds.


Methamphetamine exhibits its full effects faster when smoked than injected, as the pulmonary blood is pumped to the brain faster than venous blood. The effects can typically last up to 12 hours when taken orally, and up to 8 hours by other routes of administration. It is worth noting that for naïve/first-time users the effects of methamphetamine can last for up to twice as long as these figures – for oral administration the effects can last as long as 24 hours. The effects of methamphetamine can last for several days, especially if repeat doses are used even if the total use spans a relatively short time frame. Tolerance can build quickly, causing people to use increasingly large amounts of the drug. Repeated high dose administration has been linked to rapid reduction of striatal dopamine transporter activity.


Often psychological effects of methamphetamine are similar to amphetamine and other dopaminergic stimulants, though generally far more intense and longer lasting. These similarities include marked increases in alertness, sociability and confidence (users often find themselves becoming very chatty), focus/motivation and euphoria. Other effects include the impression of time compression, thought acceleration and organisation and analysis enhancement. When the drug is injected or smoked this euphoric rush can be very intense, but can fade long before the stimulating and physical effects of the methamphetamine fully wears off. This can lead to compulsive redosing, compounding the physical effects of the drug.


The energising effects of methamphetamine can decrease feelings of tiredness. This is why it has sometimes been used by people who want to continue physical activities, like dancing, for long periods of time. Methamphetamine may be used in ‘chemsex’ scenes for the reduced tiredness, as well as enhancement of sexual pleasure and increased libido. Meth has been used by professionals and students, to help them work for longer periods of time. Use in these situations is generally uncommon in the UK as users will often opt for other stimulants such as amphetamine or methylphenidate (Ritalin). Places where the drug is prevalent usually have limited access to other stimulant drugs, leading to people only having access to methamphetamine. In the UK, methamphetamine is rarely used as people have ready access to more typical stimulants. Common examples include MDMA, amphetamine sulphate and mephedrone. The emergence of new psychoactive compounds may play a role in reducing the use of some more common drugs.


Reported undesirable effects of meth include paranoia, violence/aggression and short temper, irritability and anxiety. Psychotic symptoms, resembling those associated with schizophrenia, can occur when using methamphetamine. These can include paranoid thoughts, or even delusions. These thoughts and delusions can consist of the belief that people are spying on you or recording your movements, or believing that you are being targeted for a crime such as a robbery. Hallucinations can occur, including hearing music that isn’t there or hearing people talking about you. With methamphetamine, owing to the more powerful and longer lasting nature of the drug, the hallucinations can include seeing shadow people, either in one’s peripheral vision or, in extreme cases, fully formed in focus. Psychotic symptoms may happen during methamphetamine intoxication and can last for days or weeks after the intoxication phase of drug use.


Physical effects of methamphetamine include: increased heart rate and constriction of blood vessels (higher blood pressure), increased energy, ‘physical euphoria (often described as a pleasant tingling sensation), dilated pupils, appetite reduction, dry mouth and a rise in body temperature.


The after effects, or ‘come down’ from methamphetamine can last for several days following drug taking and can be described as a rebound from the ‘high’, though less intense than withdrawal symptoms. People often feel muddled, irritable, socially incapable, depressed, tired and anxious. People may also experience an inability to sleep (insomnia), restlessness, twitching, muscle aches and both perceived and physical fluctuations in temperature. At high doses, this ‘come down’ can be severe – involving vomiting, diarrhoea and psychotic episodes similar to those that occur in schizophrenia.

Does Methamphetamine have any medical uses?

Methamphetamine, produced under the brand name Desoxyn, can be used to treat many of the same conditions medical amphetamine is used for. In America Desoxyn is prescribed, in 5mg doses, to treat obesity and ADHD in cases where people have not responded to other forms of treatment. Due to its potential for abuse it is licensed as a last resort only, and is not routinely prescribed.

Methamphetamine may have potential uses in treating depression, in particular for those who have low mood and lack of motivation as a result of depression. However, conventional antidepressants, or even other amphetamines, are almost always more appropriate.

Due to methamphetamine’s high potential for abuse and lack of clear benefits over amphetamine to outweigh this, methamphetamine is not a prescription drug in the UK.

What are the risks of using Methamphetamine? Can they be avoided or reduced?

Fatal overdoses from methamphetamine use occur more frequently than for other stimulants such as amphetamine sulphate, with 15,489 deaths associated with methamphetamine use in America in 2019. This is generally due to methamphetamine induced heart attacks or strokes resulting from the rise in blood pressure and constriction of blood vessels. Methamphetamine also causes a marked increase in serotonin, and high doses can lead to serotonin syndrome. This causes overheating and high blood pressure. People with pre-existing heart problems, and people at increased risk of heart disease and strokes, are more likely to experience such complications from taking methamphetamine.

Higher doses of methamphetamine can induce stimulant psychosis, presenting as paranoia, delusions and hallucinations. Some people have become violent, harming themselves and/or others in states of methamphetamine induced psychosis. Lack of sleep from repeated doses can increase the risk of symptoms. Some people who experience symptoms of psychosis do not fully recover, experiencing lasting symptoms. People taking methamphetamine with a history, or family history, of mental health problems are more likely to experience methamphetamine related mental health problems.

Some people may inject methamphetamine, which carries much higher risk. This includes the chance of getting HIV, hepatitis or bacterial infections, as well as increased risk of addiction to the drug. If you choose to inject despite the increased risk, this can be reduced by using new needles and injecting equipment. You can get these from needle exchanges, which may be found in pharmacies or hospitals.

Are there health conditions that make Methamphetamine more dangerous?

Yes. Methamphetamine is potentially more risky for people who have pre-existing heart conditions, or who have or are at risk of circulation problems including high blood pressure.


Methamphetamine can worsen glaucoma due to the changes it can have on blood pressure.


Methamphetamine may be riskier for people with mental health problems. People with schizophrenia (or family history), or a history of psychosis should avoid using methamphetamine as they tend to be much more sensitive to experiencing psychotic side-effects. This could trigger a relapse of psychosis or schizophrenia.

Can Methamphetamine be mixed with other drugs?

Taking methamphetamine with other stimulants can result in very high heart rate, blood pressure and body temperature. Methamphetamine may mask the early warning signs of depressant drugs such as alcohol or opioids. This can lead to people taking more than they otherwise would, increasing the risk of overdose from the depressant drug.


Methamphetamine can be very dangerous if you are currently taking a monoamine oxidase inhibitor (MAOI) antidepressant, as both increase extracellular serotonin and can lead to serotonin syndrome when used together.  The analgesic opioid tramadol can increase the risk of seizures when combined with methamphetamine, as the isomers of tramadol increase the extracellular levels of 5-HT and noradrenaline through reuptake inhibition, so the two should not be mixed. Mixing with tramadol may also increase the risk of damage to the heart and of psychosis.

Is Methamphetamine addictive?

Methamphetamine is considered to have an extremely high potential for abuse. Using methamphetamine regularly is likely to lead to both physical dependence and psychological addiction to the drug. Methamphetamine use can become increasingly compulsive and out of control, with many users experiencing withdrawal symptoms when not taking the drug. Withdrawal symptoms are generally a rebound from the effects of the drug. Methamphetamine withdrawals typically include a strong ‘crash’, anxiety, fatigue and lethargy, vivid/lucid dreams, cravings for the drug, insomnia and depression.

What are the long-term effects of Methamphetamine?

Long term use of methamphetamine can cause significant harm and seriously impact quality of life.


Long term use of methamphetamine at moderate to high dosage is considered to be highly neurotoxic. Long term use can damage the heart and result in an irregular heart-beat, a form of cardiotoxicity. Long term use can result in anhedonia; a general difficulty in finding pleasure in life without the drug, which can lead to increased difficulty in quitting the drug. It is difficult to establish to what extent anhedonia is a contributing factor to addiction, but the risk of this resulting from heavy sustained use should be taken very seriously. Some of the long-term side effects of use such as malnutrition and cancer may be linked to adulterants in supply on the street, as well as poverty and a chaotic lifestyle that can result from addiction.


Methamphetamine dependence can often cause people to suffer serious sleep problems, poor nutrition and extreme weight-loss (due to the reduction in hunger), which can cause an accelerated appearance of aging.


Methamphetamine can lead to gum disease and damage to peoples’ teeth caused by the ‘dry mouth’ effect, where people on the drug are not producing enough saliva to protect their mouth. This is frequently portrayed in the media, though often exaggerated. Gum disease should be recognised as a side effect from consuming methamphetamine – and not only when smoking the drug.

Methamphetamine harm reduction advice

Be careful what, and how much, you are taking

Methamphetamine can often be taken accidentally due to being mis sold as another drug in areas where it is a larger part of the drug scene (such as America and Australia), which can be a very stressful experience. Many users are concerned by the high levels of stigma towards the drug, as well as the very long duration of action compared to most stimulants. The duration can lead to a higher chance of something going wrong, extend any uncomfortable and unwanted effects, as well as cause further disruption to one’s day/night. If you are worried that you have consumed methamphetamine by accident, you should stay cool and hydrated, as well as ensuring that you are not alone. It can be very important to have someone to help you during the experience, and judge if medical care is needed. Medical care should be sought if you are experiencing chest pains or tunnel vision, or are becoming a danger to yourself or others.


Methamphetamine purity can vary by batch. In 2019, methamphetamine in the UK varied in content from 12% to 87%, with an average (mean) purity of 79%. The current strength in the UK is not known, but in 2022 methamphetamine in France had purity between 77 and 100%. This is a large variation in strength, so users should be careful not to inadvertently take more than required for the desired effects. Unlike methamphetamine found in Australia or America, in the UK (and Europe) it is generally produced in high-tech Dutch labs. This means that it is more likely to be isolated as the more active dextro-isomer. Just like for amphetamine, this form of methamphetamine is considered to be stronger than mixtures of the dextro and levo isomeric forms, which users should bear in mind. Methamphetamine can be cut with dangerous and toxic fillers, and other psychoactive drugs.


It is always a good idea to start with a low dose and work up to a comfortable and satisfactory dose. Even if the methamphetamine is pure, higher doses carry greater risks.



Injecting drugs tends to be much more harmful

It is much easier to take too much when injecting the drug. Although the doses are not significantly different hen comparing routes of administration, the rush created upon administration is much more intense when injecting the drug, which can be overwhelming for some people, and puts greater strain on the body. Injection is also associated with a range of other risks, including infection, damage to the veins and increased risk of addiction.



Tolerance is a warning sign

Increasing tolerance to a drug is an early sign that the body and brain are changing in response to the drug. Tolerance, the need to administer increasingly larger amounts of a drug to obtain the same effect, is a sign of lingering changes in brain chemistry. This can often be a sign that use is transitioning from recreational use to becoming dependant. Methamphetamine will exhibit cross-tolerance with all dopaminergic stimulants (such as amphetamine, methylphenidate and cocaine).


If you experience tolerance developing to stimulant drugs, it may be a good idea to reassess your use and consider taking a break.

Myths and misunderstandings

Methamphetamine dependence can happen from just one use

Forming a physical dependence, such that withdrawal symptoms appear when you don’t take the drug, requires repeated uses in a short space of time. However, some users feel that they ‘fell in love’ with the drug (craving its effects) from their first experience with it, as it can be immediately pleasurable. Methamphetamine can give the user seemingly unlimited energy and motivation, and having experienced it once, the temptation to use again may arise the next time a person feels in need of the effects.


It is also worth noting that the rebound effects from methamphetamine may be confused with withdrawal effects and therefore physical dependence.



Methamphetamine destroys people’s faces and causes dental decay

Whilst long-term use of methamphetamine can accelerate aging and contribute to gum decay, the images portrayed in the media are often exaggerated. The term “meth mouth” originated from a report by the Academy of General Dentistry, a report not corroborated by any supporting data or research, but rather a series of case studies about amphetamine related dental disease.


The cause of methamphetamine related dental disease/decay is often reported in the media and pop-culture as resulting from smoking the drug. Whilst the exact causes are not fully understood, and cutting agents found in meth may damage the gums when smoked, the primary causes of dental decay are believed to be dry mouth, increased consumption of sugary foods and drinks, grinding one’s teeth together and infrequent oral hygiene.


The symptoms can be mitigated through ensuring good oral hygiene, limiting the consumption of sugary drinks (although, they can be a reliable and accessible energy source when it is not possible to eat) and chewing sugar-free gum (chewing gum helps to reduce the damage done when grinding teeth and stimulates saliva release).



Methamphetamine must be smoked or injected

Methamphetamine in the media often focusses on smoking/injection of the drug. Whilst most users do smoke methamphetamine, it can be taken orally and by snorting the drug as well, which can reduce the range of harms associated with use.



Methamphetamine can be used to improve performance in school, work or sports

Stimulants are often used in the treatment of ADHD, and can give non-affected people the feeling/perception that they are more motivated and/or performing better. In reality, academic performance and concentration aren’t improved by stimulants like methamphetamine, and in some cases (such as in associative learning) can even worsen people’s results.


Stimulants do prove more effective when used to improve sports performance, such as endurance and strength, but strenuous exercise can greatly increase the risk of dangerous side-effects associated with stimulant use.


From prohibited to prescribed: The rescheduling of MDMA and psilocybin in Australia

Authors Octavian Dixon Ritchie, Cameron N Donley and Gabrielle Dixon Ritchie Published September 6, 2023 Background On February 3, 2023, the Therapeutic Goods Administration (TGA), Australian Government Department of Health and Aged Care, announced that on July 1, 2023, the psychedelics 3′4-methylenedioxymethamphetamine (MDMA) and psilocybin will be medically accessible and regulated for psychiatric use in  …