What is Project Twenty21?

Project Twenty21 allows eligible patients to access medical cannabis treatment at a capped price, and have their treatment tracked by Drug Science. 

Drug Science will use the data from Project Twenty21 to provide evidence for NHS funding of medical cannabis treatment.

Receive monthly updates and the latest news on our data findings.

Watch our video on how Project Twenty21 works



You will need to make sure that you meet the eligibility criteria of your chosen clinic and inform them that you wish to participate in Project Twenty21 before your first appointment with a clinician (we also recommend you remind your clinician at your first appointment).


Most appointments are done virtually, although some clinics do also offer face-to-face. The doctor will work with you to complete an initial assessment and questionnaire to establish your existing condition, symptoms, any previous/current medications or therapies and any history of cannabis use. It is up to the doctor to decide whether to prescribe medicinal cannabis products based on this initial assessment - attending a consultation does not guarantee a medical cannabis prescription will be issued.




Your prescription will be couriered to you in the post once payment has been made to the dispensing pharmacy as advised by your clinic. Your clinic will decide how often you need to see a doctor or nurse and advise you of any follow-up appointment schedule - this is a minimum of once every three months. Your data will be collected every three months via emails from Sail, our data collection system for the project. You must fill out these questionnaires and attend your follow-up consultations in order to remain with Project Twenty21.

Project Twenty21 products remain capped at £150 per product (based on monthly recommended dose) until further notice. This will only differ if you are prescribed a product that isn’t on our Formulary. Typically, patients prescribed flower will require up to 1g per day, equating to £150 each month. For epilepsy patients, a month’s treatment is capped at £550. Your clinician will be able to advise the total cost at your appointment, and you have the right to refuse the prescription if you’re unable or unwilling to pay.



Price Guide

Initial Consultation

From £70

Follow-up Consultation

From £49

Twenty21 Flower

~ £5 per gram

Twenty21 Oil

~ £5 per ml

Repeat Prescription

Up to £30

Consultation and repeat prescription costs are set by the clinic - simply view our clinics to find their prices

Your data is collected through questionnaires that are sent out via email every three months by our data collection system, Sail. It is then anonymised for analysis by the Drug Science team. We use this data to publish monthly figures and data insights in the Project Twenty21 newsletter, as well as more detailed research which we publish in medical and scientific journals to help influence policy change.

A ‘licensed medicine’ is a medicine that has a marketing authorisation from the UK Medicines & Healthcare products Regulatory Agency (MHRA) or European Medicines Agency (EMA), enabling it to be prescribed in the UK. The issue is that medical cannabis is an 'unlicensed medication', which makes it very difficult for producers to provide detailed product information and price lists because of the strict 'marketing' restrictions. Producers cannot state any claims about its benefit for medical conditions, the required dose or how to take it. Your doctor or dispensing pharmacist can answer questions on dosage and administration.


The Project Twenty21 formulary includes a range of indica & sativa flower products with varying CBD & THC ratios as well as an increased number of different oils. These are produced by our project partners:


We are aware that the Twenty21 formulary might not suit all patients. This is why clinicians are free to prescribe a product outside of our formulary if a Twenty21 product is deemed unsuitable. Your data can still be collected and submitted into our registry and you will still be part of the project - so you can still help us get closer to our goal of NHS access.

Yes. We understand that sometimes it is necessary for patients to move to a different clinic. Simply go to our Clinic Directory to choose a new clinic, then contact the new clinic making it clear that you're already with T21 and which clinic you need to be moved over from.

Your new clinic will need written confirmation from you before they notify our technical team to move your data across smoothly.


Read your rights as a patient to changing clinic 

Alta Flora, a Twenty21 founding industry partner, has launched an app called Eva for patients who are prescribed medical cannabis. Eva enables the collection of real-time patient self-reported data on symptoms, interactions with other drugs, and effects on symptoms and Quality of Life.


The app is now available to download on iOS and Android, find it in the app store.


Watch demo here.


Eva is a support tool for the patient use only, although you can choose to share this data with your doctor at your appointments. This data cannot be accessed by Drug Science and is not at all linked to our own data collection for the project.

Patient questionnaires for the project data collection are sent out by email once the patient is registered with a clinic and has received a login for our data collection system. Please contact your clinic if you require any further support around filling out questionnaires.  

Originally, we were running the study until the end of 2021 (hence the name), but Drug Science has worked with the licensed-producers to make sure it can run at least until the end of 2022 and hopefully beyond. Although we would love to reach 20,000 patients, we have no maximum number of patients allowed onto the study. The more data we can gather, the stronger our evidence of outcomes will be.

Patient Led Engagement for Access (PLEA) - a UK volunteer-run organisation challenging the inequalities in access to cannabis-based medicinal products. As the UK's leading medical cannabis patient advocacy group, PLEA provides support and advice to patients through events and high quality online resources hosted on their website. Become a community member for free here.


MedCan Support - an educational hub for parents and carers looking to learn more about cannabis and how it could potentially help their children. It taps into the latest research and is in collaboration with the world leaders in cannabis use for paediatric care.


Release - the team at Release provides free non-judgmental, specialist advice and information to the public and professionals on issues related to drug use and to drug laws. Helpline: 020 7324 2989 or email: 


Drug Science T21 team - we’re only a small team so we’re unable to answer every email we receive, but if your query cannot be answered by a clinic or one of the organisations above, you can email us at 

No. You can specify the pharmacy you would like to use to dispense your prescription, however, this might incur additional charges. Currently, the main pharmacies dispensing subsidised Twenty21 products are CBPM access (Rokshaw) and Dispensary Green, which do not add any extra costs.