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.

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. It is also why the format matters as much as the amount: an inhaled preparation and a swallowed oil deliver the same daily quantity very differently, so a change of route is itself a change of dose in practical terms. The routes and how they behave are set out in how cannabis-based medicines are taken.

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.

1. A starting point below the expected effective level, chosen from your history, other medicines and the condition being treated
2. A fixed period at that level — usually several days — before any change
3. A small, defined increase if there has been no benefit and no troublesome effects
4. Repeat, one variable at a time, until benefit appears or side effects set the ceiling
5. 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.

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, and a benefit that would have appeared in a month can be missed if the amount is pushed up too fast and side effects force a stop first. Going slowly gives both the benefit and the tolerance to side effects time to show themselves.

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.

How the starting point is chosen

The first amount is deliberately set below the level expected to work. It is not a guess so much as a cautious estimate, drawn from your history and circumstances and designed to be increased.

Several things push that estimate up or down. Someone who has never used cannabis is usually started very low, because their response is unknown. Previous regular use tends to mean some existing tolerance. Other medicines matter too, particularly sedatives and anything that shares the same routes of metabolism, because the combination can be stronger or less predictable than either alone. Age, other health conditions and the specific problem being treated all feed in as well.

The point of starting low is not to keep you undertreated. It is to find the smallest amount that helps, because in this field a bigger dose is not automatically a better one — beyond a certain point, most people get more side effects rather than more benefit. We never state a specific dose on this site; the numbers that apply to you come from your prescriber.

What a follow-up review looks at

Titration is not a single decision but a series of them, made at reviews. Each one asks the same questions: is it helping, at what cost, and what should change next.

• Response. Has the symptom you are treating actually improved, and in a way that matters to daily life rather than only on paper?
• Side effects. What are you noticing, are they easing or persisting, and are any of them concerning enough to act on?
• Function. Sleep, activity, mood and the ability to do ordinary things — often the most honest measure of whether treatment is working.
• Next step. Hold, increase, change the route or timing, or stop — one change at a time, so the effect of each can be seen.

This is why the diary matters. A review built on a clear record is far more productive than one built on trying to remember six weeks at once, and it is the single most useful thing you can bring.

Questions worth asking your specialist

Because there is no fixed dose, the plan itself is what you want to understand. Useful questions to ask at the start include:

• What is my starting point, and how and when will we increase it?
• How long should I hold at each level before we change anything?
• What improvement would count as success, and when will we judge it?
• Which side effects should I expect early, and which should I report straight away?
• What happens if it does not work — what is the plan to stop?

A prescriber who can answer these, and who sets a date to review the trial rather than increasing indefinitely, is running it properly. Writing the answers down where you can see them also helps you stick to the plan on the days when progress feels slow, which is precisely when people are most tempted to change things on their own.

Patient guide · Written by the Flora House editorial team · Last reviewed: 7 October 2026