How UK clinics decide who to consider.

There's no official national list of who qualifies. Each clinic sets its own criteria within the law and professional guidance, and they're more alike than different. What follows is what nearly all of them look for.

Do I need a diagnosis?

Yes. You need a diagnosis, made by a doctor. Official guidance covers only a few situations. NHS prescriptions in England are rare, and the NHS says they're only likely for a small number of conditions. NICE's guideline also recommends cannabis-based medicines in only a few situations. Outside those, each clinic decides which conditions it will consider. A specialist doctor then looks at each person's case on its own merits.

Do I need to have tried other treatments first?

Yes, usually. Clinics need to see that conventional treatment has been tried and hasn't given enough benefit, or that you couldn't tolerate it. The common yardstick is at least two licensed treatments, which could be medicines, or for some conditions therapies like physiotherapy or talking therapy. "Tried" means properly: at a sensible dose, for long enough to know. If you're not sure what's on your record, your GP summary will show it, and the clinic's nurse can tell you whether it's enough.

This isn't the clinic being difficult. Most of these medicines are unlicensed, and a doctor has to be able to justify using one instead of a treatment with a licence. Your treatment history is that justification.

Nothing that makes it unsafe

A clinic will screen you for the things that make THC in particular a bad idea. The ones that most often lead to a no, or a "not yet", are:

• a personal or close family history of psychosis or schizophrenia
• unstable heart disease
• pregnancy, trying to conceive or breastfeeding
• a current serious problem with drugs or alcohol that hasn't been addressed.

Some clinics are also cautious where there has been a recent mental health crisis. None of these is a judgement on you. They're the situations where the risks are judged too high, or where something else needs treating first.

Be honest at the screening stage. Nurses have heard it all, and being open about your history keeps you safer.

What evidence will a clinic ask for?

Nearly every clinic asks for a summary of your GP record, which lists your diagnoses, your current and past medicines and recent letters from specialists. You can request it from your GP practice, or through the NHS app in England, and the clinic will tell you exactly what they need. Some accept specialist letters or hospital discharge summaries instead. Photographs of a pill packet or screenshots of the NHS app don't count. Upload your full summary of care, with every page included and nothing removed or blanked out.

Who makes the final decision?

A specialist doctor. Only a doctor on the General Medical Council's Specialist Register can start a prescription for a cannabis-based medicine. NICE says they should also have a special interest in the condition being treated. The clinic's screening tells you whether you're likely to be suitable. The doctor decides, and a team of clinicians usually reviews that decision before anything is prescribed.

A few honest extras

Meeting a clinic's criteria doesn't mean a doctor will prescribe, and it doesn't mean a medicine will help. It means a specialist can consider it. It's nearly always a private prescription, so there's a consultation fee and a monthly cost for the medicine. It's worth knowing both before you decide anything. And if a clinic tells you that you're eligible before anyone has looked at your records, it's reasonable to ask how they know.