What Is The Sinclair Method? How It Works and What the Evidence Says

The Sinclair Method is a way of cutting down on alcohol that does not ask you to stop drinking first. You take a medicine called naltrexone before you drink. The idea is that, over time, drinking becomes less rewarding. This guide explains where the method comes from, how it is meant to work, what the research does and does not show, and who it is not suitable for.

Where does The Sinclair Method come from?

The method is named after Dr John David Sinclair, a researcher at the National Public Health Institute in Helsinki, Finland.^[1] In a 2001 paper, he proposed three principles for using naltrexone in alcohol treatment:

• Give it to people who are still drinking.
• Take it only when drinking is expected.
• Continue treatment long term.^[1]

How is it supposed to work?

Drinking is partly a learned habit. Alcohol has a rewarding effect that involves the brain’s own opioid system, and each rewarded drink can strengthen the habit.

Naltrexone blocks opioid receptors.^[2] Sinclair’s theory was that if you drink while that reward is blocked, the link between drinking and reward weakens each time. Psychologists call this process extinction.^[1]

This is why timing matters. In his earlier animal research, opioid blockers reduced drinking when given alongside alcohol, but not when given during periods without alcohol.^[1] So the method is to take naltrexone only when you expect to drink.

It is worth being clear that extinction is a theory, and the research on it is still developing. Change is usually gradual, not instant, and it works best as part of a wider plan with support.

How is it different from stopping completely?

Most alcohol treatment has traditionally been built around stopping. The NHS says the aim is usually to stop completely, especially if you are dependent on alcohol. But if you are not ready to stop, or just want to cut down, you will be supported to reduce your drinking to a safer level.^[3]

The Sinclair Method starts from where many people actually are: still drinking, and wanting that to change. Some people aim to stop altogether. Others want to drink less. A clinician can help you work out a realistic goal.

Do I have to stop drinking before I start?

Usually not, and that is one of the main differences from other approaches. In one clinical trial, 121 people who were still drinking were treated without first going through withdrawal.^[4]

There is an important exception. If you drink very heavily every day, or you get withdrawal symptoms when you cut down, stopping or reducing suddenly can be dangerous. Symptoms include anxiety, difficulty sleeping, sweating, and feeling or being sick. The NHS advises getting medical help before you try to stop drinking if you get withdrawal symptoms.^[3] NICE guidance recommends supported withdrawal first for people with moderate or severe dependence.^[5]

Our clinicians will talk this through with you on your call. If you need support to reduce safely first, they will point you to the right place.

What does the research show?

The evidence is encouraging but mixed, and it helps to know both sides.

An important caveat.No large independent trial has tested The Sinclair Method exactly as described above: naltrexone taken before every drinking occasion, in people who keep drinking, over the long term. The studies below are the closest evidence available. Each differs from the method in some way, and we say how.

• The closest trial. This study followed 121 people who were still drinking. It is the closest trial to The Sinclair Method, but not identical to it. Everyone took naltrexone or a placebo daily for 12 weeks, then only when they craved alcohol for a further 20 weeks. It ran for 32 weeks, not long term. Some people also had coping skills therapy, which accepts that lapses may happen and teaches how to handle them. Others had support aimed at complete abstinence. With coping skills therapy, 27% of those on naltrexone had no return to heavy drinking over the 32 weeks, compared with 3% on placebo. With abstinence-focused support, naltrexone made no significant difference.^[4]
• The largest independent review. This Cochrane review covers naltrexone in general, not The Sinclair Method. It looked at 50 trials and 7,793 people. Most trials used daily dosing, and most involved people who had already stopped drinking before treatment. Overall, naltrexone reduced the risk of heavy drinking to 83% of the risk on placebo, a 17% relative reduction. It also reduced drinking days by about 4 percentage points, roughly 4 fewer days a month.^[6]
• A more cautious review. This 2018 review looked at people who were still drinking, but across several different medicines and dosing patterns, so it is not a direct test of The Sinclair Method either. It found no efficacy for naltrexone on total alcohol consumption, and concluded there is currently no high-grade evidence for any of the medicines it studied. The authors also noted that many of the trials had a high risk of bias.^[7]

What this means.The evidence for naltrexone in alcohol problems is real but modest. The evidence for The Sinclair Method specifically, as a full protocol, is more limited than some online claims suggest. You may see very high success rates quoted for the method. These tend to come from individual analyses rather than independent reviews, so treat them with caution. That is one reason we start with a conversation about whether it is right for you, not a promise of results.

What should I expect?

• Gradual change. The trials ran for between 12 and 32 weeks, and Sinclair recommended continuing treatment long term.^[1][4]
• A simple record. Your clinician will usually ask you to note when you drink and how much, so you both have something real to review.
• Regular reviews. Your clinician will check in on how it is going.
• Possible side effects. The most common are nausea, headache, dizziness, tiredness and sleep problems.^[2][6] If you feel unwell, stop taking it and contact your clinician.^[5]

Who is it not suitable for?

• Anyone taking opioid medicines, such as codeine, tramadol or morphine, or anyone dependent on opioids. Naltrexone blocks their effect.^[2]
• People with severe or acute liver problems, including acute hepatitis or liver failure, or severe kidney problems. Naltrexone should be avoided. If you have mild or moderate liver or kidney problems, it needs extra caution and your dose may need adjusting. Liver function should be checked before you start and during treatment.^[2][5]
• People who drink very heavily every day or get withdrawal symptoms, until they have had medically supervised withdrawal.^[3][5]
• Anyone who is pregnant or breastfeeding, or trying to become pregnant. Tell your clinician. If you are pregnant, naltrexone should only be used if the benefit outweighs the risk. It should be avoided while breastfeeding because of the potential for harm to the baby.^[2]

Because naltrexone blocks opioid painkillers, tell any doctor, dentist or paramedic treating you that you are taking it.^[2][5]

Is The Sinclair Method available in the UK?

Yes, but only through a prescriber with experience in treating alcohol problems. Naltrexone is a prescription-only medicine, and the tablets we prescribe are not licensed for alcohol dependence. Prescribing them for this is known as off-label use. UK prescribers can do this when they judge it to be in your best interests, and treatment should be started and supervised by a clinician experienced in this area.^[8][9]

NICE describes naltrexone differently from Sinclair. For moderate or severe dependence, its guidance is to start oral naltrexone after assisted withdrawal, alongside a psychological intervention, at 25 mg a day rising to 50 mg. It is usually prescribed for up to 6 months, and stopped if drinking persists 4 to 6 weeks after starting.^[5] This is a different approach from the one described above, which is one reason to discuss your options with a clinician.

Nalmefene is an alternative. Unlike naltrexone, it is licensed in the UK for reducing alcohol consumption, but only in adults with alcohol dependence who have a high drinking risk level, no physical withdrawal symptoms, and continuing psychosocial support. It is taken as needed, preferably 1 to 2 hours before drinking.^[10]

How we approach it at Drugs4Delivery

It starts with a free 15-minute call with one of our UK-registered clinicians. They will talk through your drinking, anything else you take, and what you want to change, and tell you honestly whether this approach is likely to suit you. If it is not right for you, they will explain why and what else might help.

Our clinicians follow The Sinclair Method: you take naltrexone an hour before drinking, and only on days you drink. They will go through exactly how to take it on your call. If you would prefer nalmefene, they can talk that through with you as an alternative.

If you go ahead, you will have a secure account to message the team between reviews. Calls run until 6pm on weekdays and 11am to 1pm at weekends, so you can fit the first conversation around work. You can also read more about naltrexone, who it may suit and who it is not suitable for.