How is a dose decided and adjusted?
There is no standard dose in this field. What there is instead is a process — starting below the level expected to work and increasing gradually until either the symptom improves or side effects make further increase unwise.
The short answer
- There is no standard dose. Effective amounts vary widely between individuals.
- Titration means starting low and increasing slowly, under supervision.
- It takes weeks, not days, and rushing it is the commonest self-inflicted problem.
- The target is function, not a number. Sleep, activity and daily capability are what get measured.
- Never adjust your own dose outside what your prescriber has agreed.
Why there is no standard dose
Individual response to cannabinoids varies more than for most medicines. Previous exposure, body composition, metabolism, the condition being treated and other medicines all shift the amount required.
Someone who has never used cannabis may respond to a very small amount. Someone with a long history of use may have substantial tolerance already. Both are normal, and neither can be predicted well enough to skip the process.
NICE guidance on cannabis-based medicinal products emphasises careful, monitored prescribing precisely because of this variability and the limited evidence base behind it.
How titration works in practice
The principle is start low, go slow. The specific steps are set by your prescriber and should be written down.
- A starting point below the expected effective level, chosen from your history, other medicines and the condition being treated
- A fixed period at that level — usually several days — before any change
- A small, defined increase if there has been no benefit and no troublesome effects
- Repeat, one variable at a time, until benefit appears or side effects set the ceiling
- A review point at which the trial is judged, and stopped if it has not worked
Changing one thing at a time is what makes this work. Adjusting the amount, the route and the timing together leaves no way to know which change did what.
What to record between appointments
A simple diary makes the difference between a productive review and a vague one: what you took, when, what you noticed and when, how you slept, and what you were able to do the next day.
Function is usually the outcome that matters most. A symptom score that improves while you are too drowsy to work has not helped you.
How long it takes
Expect weeks rather than days to reach a settled position, and expect the first few weeks to include side effects that ease as the body adjusts.
Drowsiness, dry mouth and light-headedness are common early and often diminish. That is one of the reasons for going slowly: an effect that would have settled in a week can look like treatment failure on day two.
It is also why driving is not advisable during titration or after any change, as set out in Can you drive on a medical cannabis prescription?
When the answer is that it has not worked
A trial that does not produce meaningful benefit should stop. That is a normal outcome, not a failure of effort, and it is what a review point is for.
A prescriber who keeps increasing indefinitely without a defined ceiling or a date to judge the trial is not managing it properly. Ask at the outset what improvement would count as success and when the decision will be made.
Stopping is covered in Tolerance, dependence and stopping treatment.
Frequently asked questions
What is the standard dose of medical cannabis?
There isn't one. Effective amounts vary widely between individuals depending on previous exposure, metabolism, the condition being treated and other medicines. That is why treatment is titrated rather than prescribed at a fixed dose.
What does titration mean?
Starting below the level expected to work and increasing in small, defined steps under supervision, holding at each level for several days, until either the symptom improves or side effects make further increase unwise.
How long does it take to find the right dose?
Usually weeks rather than days. Early side effects such as drowsiness and dry mouth often ease as the body adjusts, which is one reason for not rushing.
Can I adjust my own dose?
Not outside what your prescriber has agreed. Changing amount, route and timing together also makes it impossible to tell which change caused what, which wastes the trial.
What if it does not work?
Then the trial should stop at the review point. That is a normal outcome. Ask at the start what improvement would count as success and when the decision will be made.
Sources and further reading
Every factual statement on this page is drawn from the following public sources. Links open in a new tab and are not affiliated with Flora House.
- NICE guideline NG144: Cannabis-based medicinal products
- British National Formulary: Cannabis extracts
- National Academies of Sciences, Engineering, and Medicine. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research (2017)
- NHS: Medical cannabis (and cannabis oils)
- MHRA: The supply, manufacture, importation and distribution of unlicensed cannabis-based products for medicinal use