Taking the medication
A day-by-day guide to the first two weeks of taking naltrexone — titration, side effects, what changes (and what doesn't yet).
Dr Seth Rankin
MBChB MRCGP, GMC 4467397
19 April 2026
5 min read

The first two weeks of the Sinclair Method are about settling into the routine of taking the tablet, getting through any side effects, and beginning the slow process of pharmacological extinction. Here's what most patients experience.
You receive your medication and your titration plan. Most patients start at one quarter of a 50mg tablet (12.5mg). Take it with food, one hour before you plan to drink. If you're not drinking on day one, you don't take a tablet — you start when your next drinking occasion comes up.
Some patients feel a slight queasy sensation an hour after the first dose. Most feel nothing. There is no immediate change to how alcohol feels yet.
Stay at the quarter-tablet dose for 5-7 days. Take it before each drinking occasion. Most patients describe these days as 'normal but slightly tired' or 'a bit foggy first thing.' Mild nausea is the most common side effect and usually settles within the week.
You may notice that drinks feel slightly less intense than usual — but the effect at this dose is small. Don't expect dramatic change yet. The titration is about building tolerance to the medication, not about extinction.
Move to half a tablet (25mg). Same protocol — one hour before drinking. Most side effects from the first week have settled. Some patients notice the medication's effect on drinking is more apparent now: a slightly weaker pull toward a second drink, a touch less satisfaction from a strong drink.
By day 12-14 you'll typically move to three-quarters of a tablet (37.5mg). At this point you're approaching the full therapeutic dose. The medication is doing real work.
You build the habit of taking the tablet on time. This is the single most important behaviour change.
Side effects, if any, settle.
Subtle reduction in the pleasure of drinking starts to register.
Small reductions in the number of drinks per session may begin (often you don't notice yourself).
Cravings are not yet substantially quieter
Total weekly intake hasn't usually fallen by much
You don't feel transformed
The 'urge' to drink is still there
This matters. Many patients expect a more dramatic effect in the first two weeks. The Sinclair Method is gradual extinction, not pharmacological cure. The big changes come at week 4-6 and beyond.
Set a phone alarm one hour before your usual first drink
Keep tablets in two places (home and bag/wallet)
Drink a large glass of water before the first alcoholic drink
Track your drinks (how many, what time) — useful data for your nurse and useful self-awareness for you
Don't expect to feel transformed
Message your nurse if anything feels off
'I drank without remembering to take the tablet.'
Don't beat yourself up. One missed-dose session doesn't undo previous progress. Get back on track at the next planned drinking occasion.
'I'm having mild nausea every time.'
Take with food, slow the titration if needed, message your nurse. It usually settles within 7-10 days.
'I don't feel any different.'
That's normal at this stage. The major changes happen at weeks 4-6 and beyond. The first 14 days are foundation.
Clinically reviewed
Dr Seth Rankin · MBChB MRCGP, GMC 4467397
Last reviewed on 19 April 2026
Next review due 19 April 2027
Reviewed by the LoveMyLife clinical team
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