What Is The Sinclair Method? How It Works and What the Evidence Says
The Sinclair Method uses naltrexone before drinking to gradually weaken the pull of alcohol. How it works, what to expect, the evidence, and who it may not suit.
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, and over time drinking tends to feel 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.
Key points
- You take naltrexone before drinking, so that over time drinking becomes less rewarding.[1]
- Most people do not need to stop drinking first, but anyone drinking very heavily every day needs medical help to cut down safely.[3][4]
- The evidence is mixed. It helps some people, and the support you have alongside it seems to matter.[4][6][7]
- It is not suitable for everyone, including anyone taking opioid painkillers.[2]
Where does The Sinclair Method come from?
It is named after Dr John David Sinclair, an American researcher who spent most of his career studying alcohol in Finland, latterly at the National Public Health Institute in Helsinki. He died in 2015.
In a 2001 paper, Sinclair set out three principles for using naltrexone in alcohol treatment: give it to people who are still drinking, take it only when drinking is expected, and continue the treatment long term. Those three principles are what people now call The Sinclair Method.[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 every rewarded drink strengthens the habit a little more.
Naltrexone blocks opioid receptors.[2] Sinclair’s idea 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 Sinclair’s research, opioid blockers helped when they were paired with drinking, but not when they were given during periods without alcohol.[1] So the method, as he described it, is to take naltrexone before drinking rather than on days you do not drink.
The change is usually gradual. It is not an instant switch, 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 that 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’s goal is to stop altogether. Others want to drink less. Your 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. One clinical trial treated 121 people who were still drinking, without asking them to go through withdrawal first.[4]
There is an important exception. If you drink very heavily every day, or you get withdrawal symptoms when you cut down, such as anxiety, difficulty sleeping, sweating, or feeling and being sick, reducing suddenly can be unsafe. The NHS advises getting medical help before you stop or reduce drinking if you get withdrawal symptoms.[3] NICE guidance also recommends withdrawal with medical support first for people with moderate or severe dependence.[5] Our clinicians talk this through with you on your call, and 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 it is mixed, and it is worth knowing both sides.
- A trial in people who were still drinking. 121 people took naltrexone or a placebo every day for 12 weeks, then only when they craved alcohol for a further 20 weeks, alongside either coping skills therapy or abstinence-focused support. With coping skills therapy, 27% of people on naltrexone had no return to heavy drinking over the 32 weeks, compared with 3% on placebo. With abstinence-focused support, naltrexone made no difference.[4]
- The largest independent review. A Cochrane review of 50 trials and 7,793 people found naltrexone reduced the risk of heavy drinking to 83% of the risk in people taking a placebo, and cut the number of drinking days by about 4%.[6]
- A more cautious review. A 2018 review looked only at people who were still drinking when treatment started. It found no clear effect of naltrexone on total alcohol consumption, and concluded there is not yet high-grade evidence that the medicines it studied, including naltrexone and nalmefene, help people control their drinking.[7]
Put simply, naltrexone helps some people but not everyone, and the support you have alongside it seems to matter. You may see very high success rates quoted online for The Sinclair Method. These tend to come from individual analyses rather than independent reviews, so treat them with caution.
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 reviews how it is going with you.
- Possible side effects. The most common include 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 liver or kidney problems. Your 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 medical help to reduce safely.[3][5]
- If you are pregnant, trying to become pregnant or breastfeeding, tell your clinician, as naltrexone may not be suitable.[2]
Because naltrexone blocks opioid painkillers, you must tell any doctor, dentist or paramedic treating you that you are taking it.[2][5]
Is The Sinclair Method available in the UK?
Yes, through a prescriber. Naltrexone is a prescription-only medicine. The naltrexone we prescribe is not licensed for alcohol dependence, so prescribing it for this is known as off-label use. UK prescribers, including pharmacist independent prescribers, can do this when they judge it to be in your best interests.[8]
It is worth knowing that NICE describes naltrexone use a little differently from Sinclair: alongside psychological support, and for more severe dependence after withdrawal.[5] The licensed medicine closest to the Sinclair approach is nalmefene, which is taken on days you are likely to drink, preferably 1 to 2 hours beforehand.[9]
How we approach it at Drugs4Delivery
It starts with a free 15-minute call with one of our UK-registered clinicians. They talk through your drinking, anything else you take, and what you want to change, and they will 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.
Sinclair’s original instructions were to take naltrexone only before drinking. In practice, our clinicians usually recommend one tablet a day, and tailor how you take it to you. If you are advised to take it before drinking, take it at least an hour beforehand.
Some people prefer nalmefene, and your clinician can talk it 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.
Sources
- 1.Sinclair JD. Evidence about the use of naltrexone and for different ways of using it in the treatment of alcoholism. Alcohol and Alcoholism, 2001;36(1):2 to 10.
- 2.Naltrexone hydrochloride. British National Formulary (BNF), NICE.
- 3.Alcohol-use disorder. NHS.
- 4.Heinälä P, Alho H, Kiianmaa K, Lönnqvist J, Kuoppasalmi K, Sinclair JD. Targeted use of naltrexone without prior detoxification in the treatment of alcohol dependence: a factorial double-blind, placebo-controlled trial. Journal of Clinical Psychopharmacology, 2001;21(3):287 to 292.
- 5.Alcohol-use disorders: diagnosis, assessment and management of harmful drinking (high-risk drinking) and alcohol dependence (CG115). NICE.
- 6.Rösner S and others. Opioid antagonists for alcohol dependence. Cochrane Database of Systematic Reviews, 2010, CD001867.
- 7.Palpacuer C and others. Pharmacologically controlled drinking in the treatment of alcohol dependence or alcohol use disorders: a systematic review with direct and network meta-analyses on nalmefene, naltrexone, acamprosate, baclofen and topiramate. Addiction, 2018;113(2):220 to 237.
- 8.Off-label or unlicensed use of medicines: prescribers’ responsibilities. Medicines and Healthcare products Regulatory Agency (MHRA).
- 9.Nalmefene. British National Formulary (BNF), NICE.
Clinically reviewed by Dr Wisam Tatari, Clinical Lead, Independent Prescriber, GPhC 2063769.
Last reviewed 15 September 2026. We review this page when the clinical guidance it describes changes, and at least once a year.
This article is general information, not medical advice. Always speak to a clinician about your own circumstances. For urgent medical help call 111, or 999 in an emergency.