Understanding how the Sinclair Method works makes the rest of it far easier to follow. This is not a willpower technique dressed up in science. It rests on a specific idea about learning, one that has been tested in animals and in people, and once you grasp it, the odd-sounding instructions start to make sense. The short version: alcohol teaches your brain to want alcohol. Naltrexone interrupts the lesson. Drink often enough while that lesson is blocked, and the wanting fades.
This guide covers the mechanism, the classic experiment behind it, why cravings sometimes get louder when you stop, and what a realistic timeline looks like.
Please read this first if you get shakes, sweats or bad anxiety in the morning, or if you drink to steady yourself, do not stop or cut down on your own. Sudden cuts in heavy drinking can cause seizures. Speak to your GP or an alcohol service before making any changes.
Five Key Takeaways
- Alcohol teaches, it does not just intoxicate. Every drink releases endorphins that tell your brain the experience was worth repeating. Repetition strengthens that lesson.
- Naltrexone blocks the lesson, not the drink. You still taste it, and you still get drunk. What goes missing is the chemical tick of approval afterwards.
- The unlearning has a name. Pharmacological extinction, and it follows the same rules Pavlov described over a century ago.
- Stopping abruptly can make cravings louder. Researchers call this the alcohol deprivation effect. It is a real phenomenon, not a character flaw.
- Think months, not weeks. Most people who respond notice change over three to six months, and the original protocol has no fixed endpoint.
How the Sinclair Method Works in the Brain
Start with what alcohol actually does, because the drinking part is only half of it.
When you drink, your brain releases endorphins. These land on opioid receptors and produce a pleasant, reinforcing signal. That signal is the brain’s way of filing the experience under “worth doing again”.
Repeat that often enough, and the filing becomes a habit. The pathway strengthens, cravings sharpen, and cutting back gets harder. Nothing about that process requires weakness or poor character. It is ordinary learning, running on a substance that happens to hijack it.
Naltrexone changes one link in that chain. It occupies the opioid receptors, so when the endorphins arrive, they find nowhere to land. You still taste the drink. You still feel the alcohol. What goes missing is the reward signal that would normally reinforce the habit.
Drink under those conditions repeatedly, and the brain slowly revises its filing. That revision is what researchers mean by pharmacological extinction.
Pharmacist’s tip: the drug does not make drinking unpleasant, unlike disulfiram. It makes drinking less rewarding. That difference is why people can stay on it while still drinking socially.
The Pavlov Experiment Behind the Sinclair Method
The clearest way to understand extinction is the experiment nearly everyone half-remembers from school.
Pavlov rang a bell before feeding his dogs. Before long, the bell alone made them salivate, because it reliably predicted food. Then he rang the bell and brought no food. The dogs kept salivating at first. Gradually, as the bell stopped delivering, the response faded away.
Map that onto drinking, and the parallel holds.
- Your cue is drinking alcohol
- That reward is the endorphin release
- The learned response is craving, plus the pull to keep going once you start
On this approach, the cue still happens, but the reward does not arrive. So the learned response weakens, session by session, the same way the salivation did.
One detail matters. Extinction only works if the response is actually made. The dogs had to hear the bell. You have to drink while the block is active. That is not a loophole in the method; it is the entire mechanism.
Researchers tested this rather elegantly in animals. Rats that drank alcohol while on an opioid blocker cut their intake and kept drinking less afterwards. Littermates given the identical amount of alcohol by injection, so they never made the drinking response themselves, showed no such reduction. The response has to be performed while the reward is blocked.
The Sinclair Method works by blocking alcohol’s endorphin reward with naltrexone. Drinking repeatedly without that reward weakens the learned craving, a process called pharmacological extinction.
Why Sinclair Method Timing Is Key to How It Works
Everything above explains why the instruction is so specific: take the tablet one to two hours before you drink.
Naltrexone reaches peak levels in the blood roughly an hour after you swallow it. Take it then, and the block is at full strength when the alcohol arrives. Take it the morning after and the block is active while nothing is happening, which teaches your brain nothing at all.
That is also why a missed dose is worse than it sounds. Drinking without the tablet is not a neutral gap in treatment. It is a session where the reward does arrive, which reinforces the habit rather than weakening it.
Nobody manages this perfectly. Occasional slips will not undo months of progress. A pattern of them, though, will stall it.
Why Cravings Sometimes Get Louder
Here is something people find genuinely reassuring, and it deserves proper explanation.
If you have stopped drinking for a while and found that cravings got stronger rather than weaker, you are not doing it wrong. Researchers have described a phenomenon called the alcohol deprivation effect, in which a period without alcohol is followed by increased wanting, and increased consumption when drinking resumes.
The logic is not complicated. Your brain has learned that alcohol delivers. Remove the alcohol and the learning stays intact, so the expectation keeps firing with nothing to satisfy it. Time alone does not rewrite the lesson, because the lesson was never contradicted, only interrupted.
Extinction works differently. Instead of removing the cue, it removes the payoff. The brain gets the direct evidence that drinking no longer delivers what it promised, which is the information it needs to revise.
Two honest caveats belong here. Much of the deprivation-effect research comes from animal models, and human experience varies considerably. And this is emphatically not an argument against stopping drinking. Plenty of people do brilliantly with abstinence, and for anyone physically dependent, supervised withdrawal is the safer and more appropriate route regardless of what any craving theory suggests.
How the Sinclair Method Works Over Time
Be wary of any service offering you a week-by-week schedule of results. Responses vary widely, and the honest picture is slower than the marketing suggests.
The first few weeks are mostly about establishing the routine. Take the tablet before drinking, every time. Keep a simple record of days, units and how you felt. Early side effects such as nausea usually show up here and usually settle.
Over the following months, people who respond tend to notice the pull easing rather than vanishing. The urge to keep going after the first drink often softens before the urge to start does. Most people who report meaningful change describe it emerging across three to six months.
Longer term, fuller change often takes six to twelve months. Some people move towards abstinence, though most who do well end up drinking considerably less rather than stopping entirely.
One point the marketing tends to skip. The protocol’s originator argued there is no scientific reason to stop after any fixed period, and advised patients to keep a tablet available indefinitely and take it whenever they might drink. His reasoning was that the old learning can rebuild if drinking resumes unmedicated. So this is closer to a long-term arrangement than a twelve-week course, and you should know that before you start.
Pharmacist’s tip track from day one. A simple record turns a review appointment from a guess into a conversation about what actually happened.
How Sinclair Method Results Compare With Other Approaches
It is worth being fair here, because the honest comparison is more useful than a sales pitch.
Abstinence-based methods
These include mutual aid groups and NHS structured programmes, work well for a great many people and have decades of experience behind them. For anyone physically dependent on alcohol, an abstinence route with medical supervision is the appropriate starting point, and no medication changes that.
The Sinclair Method
This approach suits a different person: someone who wants to reduce rather than stop, can plan their drinking occasions, and would not otherwise engage with treatment that demands abstinence first. That is a real and sizeable group, and it is the group the method was designed for.
What the evidence says?
Where the evidence is strongest is a specific and interesting finding. Three separate controlled trials tested naltrexone against placebo under two therapy models: one that supported total abstinence, and one that taught people to cope with slips and therefore involved some drinking on medication. All three found benefit in the drinking groups. None found benefit in the abstinence groups.
That does not make abstinence wrong. It suggests naltrexone specifically works through drinking, which is exactly what the extinction idea predicts. The evidence strongly supports targeted use of naltrexone before drinking rather than taking one tablet daily on a regular basis.
Compounding at Courier
When the standard option isn’t the right fit, we can make one to order
Courier is a compounding pharmacy. Where a prescriber decides it’s appropriate for you, we can prepare bespoke, made-to-order preparations — tailored to the individual, under full clinical governance. It’s the same principle that runs through everything we do.
What Making the Sinclair Method Work Asks of You
Understanding how the Sinclair Method works also means being clear about the commitment.
- A tablet before every drinking occasion, without exception where you can manage it
- The ability to see drinking coming, since unplanned drinking is hard to medicate
- Months of patience, not weeks
- Honest record keeping, because memory is a poor guide to your own drinking
- Support alongside the medicine. Every successful trial paired naltrexone with structured psychological support, and the method’s originator was clear it should not stand alone
- No opioid painkillers, which is an absolute safety requirement rather than a preference
None of that is arduous. It is, however, more than “take a pill and carry on”, which is how the method is sometimes sold.
Making the Sinclair Method Work: Where to Start
If this fits how you think about your drinking, the first step is an assessment rather than a prescription.
Our alcohol addiction page sets out what we can and cannot offer. For the evidence behind the method, including an honest look at the widely quoted 78% figure, see our Sinclair Method guide.
A prescriber will check your drinking pattern, opioid history, liver and kidney health, other medicines and your goal. Depending on that review they may approve treatment, request blood tests, suggest nalmefene, which is licensed in the UK for reducing heavy drinking, or refer you to NHS services where supervised withdrawal is the safer route.
NHS alcohol services are free and self-referral is usually possible. For anyone wanting counselling wrapped around treatment, that route is often better resourced than a private one.
Summary
How the Sinclair Method works comes down to one idea: alcohol teaches your brain to want alcohol, and blocking the reward while you drink lets the brain unlearn the lesson. That is pharmacological extinction, and it follows the same principles Pavlov described.
The timing follows directly from the mechanism. The block has to be active while you drink, because extinction only weakens responses that are actually made. That is why a tablet an hour or two beforehand matters, and why a missed dose works against you.
Expect months rather than weeks, expect reduced drinking rather than guaranteed abstinence, and expect the commitment to be open-ended rather than a fixed course.
If you are worried about your drinking, your GP or local alcohol service is a good place to start. Courier Pharmacy offers clinician-led appointments for people who want a structured private route with proper follow-up.
FAQs
How does the Sinclair Method work in simple terms?
Alcohol releases endorphins that reward your brain and reinforce drinking. Naltrexone blocks those receptors, so drinking stops delivering the reward and the craving gradually fades.
Why do I have to drink for it to work?
Extinction only weakens a response that is actually made. The brain needs the direct experience of drinking without the reward, which is why abstinence plus naltrexone works less well.
How long before I notice a difference?
Most people who respond describe change over three to six months, with fuller change often taking six to twelve.
What happens if I drink without taking it?
That session delivers the usual reward, so it reinforces the habit. Occasional slips are survivable, but a pattern of them stalls progress.
Does it stop me getting drunk?
No. Your blood alcohol and impairment are unchanged. It blocks the reward, not the alcohol, and it may even make divided attention harder.
Is it a twelve-week programme?
Not according to the original protocol. Its originator argued for indefinite use, with a tablet taken whenever drinking is likely.
Do I have to give up drinking eventually?
Not necessarily. Most people who do well reduce their drinking considerably rather than stopping, though some choose abstinence later.
Is this better than abstinence-based treatment?
Neither is better in general. Abstinence approaches suit many people well, and are the right route for anyone physically dependent. This approach suits people who want to cut down and can plan their drinking.
This article is for information only. It does not replace a clinical assessment. Naltrexone is a prescription-only medicine and should only be started by a clinician experienced in treating alcohol dependence.
References
- National Institute for Health and Care Excellence (2014) Nalmefene for reducing alcohol consumption in people with alcohol dependence. NICE technology appraisal guidance TA325. Available at: https://www.nice.org.uk/guidance/ta325 (Accessed: 2 August 2026).
- Sinclair, J.D. (2001) ‘Evidence about the use of naltrexone and for different ways of using it in the treatment of alcoholism’, Alcohol and Alcoholism, 36(1), pp. 2–10. doi: 10.1093/alcalc/36.1.2.
- Courier Pharmacy (2026) The Sinclair Method for alcohol use disorder: how it works. Available at: https://courierpharmacy.co.uk/the-sinclair-method-for-alcohol-use-disorder-how-it-works/ (Accessed: 1 August 2026).
- Harvard Health Publishing. Can you retrain your brain to stop excessive drinking? Available at: https://www.health.harvard.edu/medications-and-treatments/can-you-retrain-your-brain-to-stop-excessive-drinking
- Courier Pharmacy. The Sinclair Method for alcohol dependence, UK guide. Available at: https://courierpharmacy.co.uk/the-sinclair-method-blocking-endorphin-driven-reward/
- Courier Pharmacy (2026) Can you drink while on the Sinclair Method? a UK guide. Available at: https://courierpharmacy.co.uk/can-you-drink-while-on-the-sinclair-method-a-uk-guide/ (Accessed: 2 August 2026).
- Courier Pharmacy (2026) Who should avoid naltrexone? A UK safety guide. Courier Pharmacy. Available at: https://courierpharmacy.co.uk/who-should-avoid-naltrexone-a-uk-safety-guide/ (Accessed: 5 August 2026).
- Electronic Medicines Compendium (eMC) (2026) [Summary of Product Characteristics]. Available at: https://www.medicines.org.uk/emc/product/8968/smpc#gref (Accessed: 5 August 2026).
- Anton, R.F., O’Malley, S.S., Ciraulo, D.A., Cisler, R.A., Couper, D., Donovan, D.M. et al. (2006) ‘Combined pharmacotherapies and behavioral interventions for alcohol dependence: the COMBINE study’, JAMA, 295(17), pp. 2003-2017.
