How TSM Works
The Sinclair Method (TSM) works through a process called pharmacological extinction. Over years of drinking, the brain, in people who suffer from alcoholism or AUD, becomes hardwired to the pleasure of consuming alcohol. It is in the unlearning of this hardwiring that TSM works*.
Nalmefene (or its sister product Naltrexone) is an opioid-antagonist medication. This means that it occupies the opioid receptors in the brain and prevents the endorphins released during alcohol consumption from occupying them. In turn, the blocking of these endorphins prevents both the production of dopamine and the brain from reinforcing the associating alcohol consumption as being a rewarding experience. It is the releasing of endorphins and production of dopamine which result in the "buzz" people feel when they drink alcohol and it is this "buzz", and the pleasure it incurs, which feeds the addiction. Repeating the combination of nalmefene followed by drinking an hour or two after taking the tablet, over time, will help the brain unlearn the addiction.
In a snapshot, for people susceptible to AUD or alcoholism, alcohol brings a euphoric reward which the brain wants more and more of. It craves alcohol because it loves the effect it brings. By following TSM, the brain is no longer exposed to the pleasure of drinking and, with time, stops searching for pleasure in alcohol and looks for it in other ways. Drinking alcohol doesn't become a nasty or dangerous experience like it does with Diulsifram (Antabuse), nor are cravings artificially kept at bay (but remain hidden under the surface) like with Campral, the addiction is unlearned and stays unlearned as long as the person remains taking their nalmefene in accordance with TSM directions prior to any drinking of alcohol**.
*Please note that no medication can claim to have a 100% success rate with all people. There will be some for whom nalmefene/naltrexone is ineffective in much the same way as, for example, paracetamol does not relieve the pain of headaches for the entire population. In clinical trials nalmefene/naltrexone have been proven highly effective (around an 80% success rate) in helping to treat alcoholism/AUD.
** Dr. David Sinclair's Definite Statement on The Sinclair Method: here.