Medical cannabis flower is one form of cannabis-based medicine that a UK specialist may prescribe. It should be treated as the exact controlled medicine named on the prescription: keep it in its dispensing container, follow the pharmacy label and do not share it. The strain name or THC percentage alone cannot tell you whether a product is suitable.
Key takeaways
- Prescribed flower is supplied through a pharmacy for a named patient; it is not interchangeable with cannabis obtained elsewhere.
- Flower may be supplied as an unlicensed CBPM, which carries additional specialist prescribing responsibility.
- UK rules continue to prohibit smoking cannabis-based products for medicinal use.
- If flower is prescribed for vaporisation, follow the prescribed route and the device and pharmacy instructions.
- THC and CBD strength are useful label facts, but they do not predict an individual response or replace clinical review.
- Report side effects and ask before changing the product, amount, frequency, route or device settings.
Prescription and legal context
The 2018 rescheduling created a route for cannabis-based products for medicinal use to be prescribed. GOV.UK states that unlicensed products for administration are subject to additional access restrictions and that smoking cannabis or a cannabis-based product for medicinal use remains prohibited. The GMC says the supply of an unlicensed CBPM must be in accordance with a prescription or direction from a doctor on its Specialist Register.
That prescription changes the legal and clinical context of the supplied product; it does not make all cannabis flower lawful medicine. Keep the original dispensing container and label. The NHS also advises keeping a copy of the prescription and any prescriber letter you have when proof may be needed.
Reading the label without over-reading it
The dispensing label should identify the patient, medicine and directions. Product packaging may also show the supplied amount, THC and CBD strength, batch information and storage instructions. Check the pharmacy label each time rather than relying on a remembered strain name or an online review.
A higher THC percentage is not a promise of greater benefit. Products with similar headline strengths can differ, batches can change and patients can respond differently. The safe comparison is the exact prescribed product and its label, discussed with the prescriber or pharmacist. Read what THC percentage means on a flower prescription for a deeper explanation.
Flower is not the only supplied form. The broader guide to how prescribed medical cannabis may be supplied covers oils, capsules and other forms, while medical cannabis oil versus flower explains the questions patients can bring to a consultation.
Vaporisation and safety questions
If the prescribed directions involve vaporisation, ask the clinic or pharmacy which device requirements and instructions apply to that prescription. Do not copy a temperature, amount or routine from a review, forum or another patient. A patient’s product, device, health risks and prescription may be different.
Tell the prescriber about asthma, COPD, cardiovascular concerns, immune-system risk, previous adverse cannabis reactions, mental-health history, pregnancy or breastfeeding, current medicines and any work or driving duties. These factors do not all lead to the same decision, but they can affect whether an inhaled form is appropriate and how it is monitored.
The NHS lists possible effects including dizziness, tiredness, feeling high, mood or behavioural change, hallucinations and suicidal thoughts, and it notes that CBD and THC can affect how other medicines work. Contact the clinical team about side effects or an unexpected response. Seek urgent help for a severe or immediately dangerous reaction.
Do not drive if impaired. A prescription does not provide a judgement that you are fit to drive at a particular time; discuss driving and work safety with the prescriber and follow current law.
Read next
- What THC percentage means on a flower prescription
- Vaping prescribed cannabis versus smoking
- How to read a medical cannabis prescription label
- Medical cannabis oil versus flower
