The Sinclair Method and liver function tests

Liver function tests (LFTs) are part of the Sinclair Method protocol because naltrexone is metabolised by the liver and, in rare cases, can cause transient changes in liver enzymes. The tests are also useful because heavy drinking itself can affect the liver, and a baseline tells us where you're starting from.

What an LFT measures

A standard liver function test panel includes:

• ALT (alanine transaminase) — released when liver cells are stressed or damaged

• AST (aspartate transaminase) — similar, also found in muscle

• ALP (alkaline phosphatase) — elevated in bile-flow obstruction

• Bilirubin — yellow pigment processed by the liver; elevated in jaundice

• GGT (gamma-glutamyl transferase) — sensitive marker of alcohol-related liver effect

• Albumin — protein made by the liver; falls in chronic liver disease

Heavy drinkers often show elevated GGT and a rise in ALT/AST. Most patients improve once drinking reduces. We tell you what your numbers are and what they mean — no test result is hidden from you.

When we test

• Baseline — before starting (or within 1 month if we agree to start without one)

• 1 month — if baseline was deferred

• 3 months and 6 months — to confirm the medication isn't affecting your liver

• Annually thereafter if you're on Ongoing

Three options for getting your LFT

Use ours: £49 via London Medical Laboratory, our own pathology lab. Same-day or next-day results into your patient portal.

Bring an NHS LFT: If you've had an LFT through your NHS GP within the last 6 months, you can upload the result to your account and we'll use it. No charge.

Defer the baseline: For low-risk patients (AUDIT under 16, no liver history, fewer than 5 years of heavy drinking), we can start you on a 28-day pack without a baseline LFT and arrange one within the first month. Your reviewing doctor decides if this fits.

What if your LFTs are abnormal?

Mildly raised enzymes are common in heavy drinkers and usually settle as drinking reduces. We'd start you on naltrexone normally, monitor at 1 and 3 months, and the trend almost always improves.

If your enzymes are significantly raised (ALT > 3× the upper limit of normal), we might switch you to nalmefene, which is metabolised differently and is kinder to the liver. Nalmefene also doesn't require routine LFT monitoring, which is convenient if you're keen to avoid further blood tests.

In the rare case of severe liver impairment (Child-Pugh B or C cirrhosis, advanced fibrosis), we won't prescribe either medication and would refer you to a hepatologist for input first.

If you've never had an LFT

Many people haven't. That's fine. Either book ours (£49) when you start, or ask your NHS GP — they can order one free of charge if you tell them you're starting a medication that requires liver monitoring. We accept LFT results from any NHS lab, private GP, or recognised private lab.

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