Liver Values After Winter: What the Numbers Mean

TL;DR: Elevated AST, ALT, or GGT in spring are common and usually reversible. Instead of a detox tea, a baseline check with four values is more informative; 6 to 8 weeks without alcohol also shows how far values recede. For NAC and silymarin the evidence is limited to inconsistent; the rest is marketing. Whether and how elevated values are treated is for a doctor to decide.

This article is purely informational and does not replace medical advice. Use, dose, and therapy should be clarified with a doctor — if ALT is above 3× the upper limit or you have upper abdominal pain, please always see a doctor.

What Winter Does to Your Liver

From October to March, alcohol consumption and calorie intake rise noticeably in Germany, statistically speaking. Christmas, New Year’s Eve, carnival parties, cozy evenings in the cold — it all adds up. At the same time, physical activity drops: less cycling, less jogging, more couch time.

The result shows up in your blood. The liver is the body’s most important metabolic organ. It breaks down alcohol, processes dietary fats, and produces bile. When the liver has too much to process for too long, the cells react — and you can see that in three values.

AST (GOT) rises with liver cell damage and muscle damage. ALT (GPT) is liver-specific and rises mainly with liver cell damage. GGT responds to alcohol, bile stasis, and medications. Together they give you a picture of what winter has done.

A typical spring result: GGT at 85 U/L (normal: below 60 U/L), ALT mildly elevated at 52 U/L. Both values below 2× the upper limit. This is common, not dramatic — but a signal a doctor can help put into context.

The good news: the liver is an organ with exceptional regenerative capacity. Mildly elevated values often recede within 6 to 10 weeks.

The Right Spring Check: Which Values Really Count

Not every lab value makes sense in a spring screening. Here is the sensible baseline panel — and what you can read from it.

Baseline panel (15–30 euros self-pay):

Extended panel for risk factors (40–70 euros): Albumin, alkaline phosphatase (ALP). Albumin below 3.5 g/dl is a sign of chronic liver damage. Elevated ALP points to bile duct problems.

In Lab2go you can document the context of each measurement: alcohol in the last 2 weeks, supplements, training. That makes it visible at the next test whether a trend is emerging.

The De Ritis Ratio: The Ratio Says More Than a Single Value

A single value tells you that something is elevated. The ratio between the two transaminases tells you more about where it’s coming from. The De Ritis ratio is AST (GOT) divided by ALT (GPT) — a division you can do yourself once both numbers are on your report.

Ratio below 1 — ALT dominates. This is the usual pattern after winter: fatty liver, diet-related strain, early liver cell damage. ALT is liver-specific, so a low ratio points to the organ itself.

Ratio between 1 and 2 — not a distinct finding, but an overlap zone. This isn’t a cleanly separated zone: in the comparison study by Sorbi et al. (Am J Gastroenterol, 1999), ratios in fatty liver reached up to 2.8, while alcoholic liver disease already started at 1.1 — both groups sit side by side in this band. A single value doesn’t separate the causes here; context decides: how long ago was your last hard training session? What medications and supplements are you taking? When was your last drink?

Ratio of 2 and above — a matter for a doctor. In the study by Nyblom et al. (Alcohol and Alcoholism, 2004), 69% of hospitalized patients with alcohol-related cirrhosis had a ratio of 2 or higher, while 64% of alcohol-dependent patients in inpatient withdrawal treatment stayed at 1.0 or below. The direction of this finding matters: a high ratio points to already-advanced liver disease — not simply to someone having drunk a lot.

The most common false alarm sits on the other side of the division: AST is also found in skeletal muscle. If you trained hard in the week before the blood draw, elevated AST is often not a liver problem but muscle soreness showing up in your blood: after an intense strength session, AST and ALT stayed above the reference range in healthy men for at least seven days afterward (Pettersson et al., Br J Clin Pharmacol, 2008). Note the date of your last hard session with every measurement, or you’ll be comparing two numbers at the next test that arose under different conditions.

And the frame around all of this: the ratio is a clue, not a diagnosis. It indicates which direction to look further — the interpretation itself needs to be confirmed by a doctor.

Evidence-Based Detoxification vs. Detox Marketing

“Detox” is one of the most misused words in the health market. The liver detoxifies continuously — around the clock, without a break. It doesn’t need juice or tea for that.

How the liver detoxifies:

The liver cleans blood in two phases. In Phase I, fat-soluble toxins are converted into reactive intermediates by cytochrome P450 enzymes. In Phase II, these intermediates are made water-soluble and excreted. For Phase II, the liver mainly needs glutathione, glucuronic acid, and sulfate. NAC supplies the sulfur for glutathione.

What is not supported for “detox” offerings:

• Juice cures: No evidence of detoxification effects. High fructose content even adds extra strain on the liver.
• Liver detox teas: Most contain dandelion or artichoke — both show mild choleretic effects (more bile flow) in large amounts, but no transaminase-lowering effect in RCTs.
• “Flushing out toxins”: The liver is not a filter you can rinse out. Toxins are conjugated to glutathione and excreted via bile or the kidney — not flushed out by fluid.

What research looks at: Studies examine the influence of less alcohol, more exercise, and weight loss in people who are overweight, as well as NAC and silymarin. Whether any of this is relevant in an individual case is for a doctor to assess based on the values. More in the next sections.

Anyone wanting to understand what liver values mean in the full context will find an overview in the guide Understanding Liver Values: AST, ALT, GGT, Bilirubin.

NAC and Silymarin: What the Evidence Shows

Two substances are most often studied in connection with liver protection and transaminases. This section puts the research into context; it is not a recommendation to use them.

NAC (N-Acetylcysteine)

NAC is the acetylated form of the amino acid cysteine. It is converted in the liver into glutathione — the body’s most important endogenous antioxidant and the central molecule of Phase II detoxification. NAC is the standard antidote for acetaminophen overdose and is used for that purpose under medical supervision.

What the evidence shows: Research examines whether NAC replenishes the liver’s glutathione reserves. There are signals from smaller studies of a lowering effect on transaminases in non-alcoholic fatty liver disease; no reliable effect size can be derived from them. Whether anything changes for a given person is shown only by a follow-up measurement — not a percentage figure.

Risks and side effects: Nausea and heartburn are described as possible side effects. Whether use makes sense at all is a matter to clarify with a doctor, especially if other medication is being taken.

Silymarin (Milk Thistle Extract)

Silymarin is the active compound complex from milk thistle (Silybum marianum), consisting of silybin, silydianin, and silychristin. The mechanisms are well studied: silymarin stabilizes the cell membranes of hepatocytes, has antioxidant effects (inhibits lipid peroxidation), inhibits NF-κB (an inflammatory pathway), and has mild anti-estrogenic effects on liver cells.

What the evidence shows: There are signals of a favorable effect of silymarin on liver values, but the evidence is inconsistent and the reported effects are small.

Interactions and risks: People taking medication should clarify possible interactions with a doctor or pharmacist. Supplements cannot replace medication.

Lifestyle: What the Research Shows

Supplements do not replace anything here. In the research, lifestyle factors have the biggest influence.

Abstaining from alcohol: The factor with the fastest effect on the values. GGT has a half-life of 14 to 26 days. After 6 to 8 weeks without alcohol, GGT is back in the normal range for most people. ALT follows within 2 to 3 weeks.

Exercise: In studies, 150 minutes of aerobic activity per week (such as cycling, swimming, brisk walking) was associated with less liver fat in NAFLD, even when weight stayed the same. The proposed mechanism: aerobic activity increases fat oxidation in the liver and improves insulin sensitivity. How far ALT follows varies a great deal between individuals — only your own follow-up measurement is reliable.

Diet: From the liver’s perspective, the following are mainly discussed:

• Fructose sources (soft drinks, fruit juices, a lot of fruit at once). Fructose is metabolized almost exclusively in the liver.
• Saturated fats from processed food.
• Omega-3 fatty acids from fatty fish are being studied in connection with liver triglycerides.
• Coffee is consistently associated with a lower NAFLD risk in observational studies — one of the most stable observations in liver research. No reliable effect size can be derived from this, though: these are associations, not measured risk reductions.

Body weight: Weight loss goes along with less liver fat. A reduction of 7 to 10% of body weight is the order of magnitude that NAFLD studies work with — whether and how far liver values follow is shown by a follow-up measurement after 3 to 6 months.

When You Need to See a Doctor

Mildly elevated values in spring are common — they are not an alarm. But four situations require medical evaluation.

ALT above 3× the upper limit: That’s 135 U/L in men and 102 U/L in women. At that point, self-tracking is no longer enough. Causes can include viral hepatitis, drug-induced liver injury, or autoimmune hepatitis.

GGT persistently above 150 U/L: If GGT is still above 150 U/L after 8 weeks without alcohol, it needs evaluation with an ultrasound and extended lab work.

Bilirubin elevated above 2.5 mg/dl: If skin or the whites of the eyes turn yellowish, bilirubin is above 2 to 3 mg/dl. That’s jaundice and always a case for a doctor.

Upper abdominal pain: A feeling of pressure or pain under the right rib cage together with elevated liver values — see a doctor immediately. This can indicate gallstones or liver inflammation.

For values below these thresholds, documenting the trend in Lab2go can help make patterns visible. A single outlier after winter is not a problem. Three measurements over 6 months without improvement is a pattern worth discussing with a doctor.

Spring Check: Four Steps of Interpretation

Why winter can stress liver values, what the numbers mean, and what research examines is covered above. To close, an overview of how an assessment typically unfolds — as information, not as instructions.

1. Baseline value: AST, ALT, GGT, and bilirubin are measured (15 to 30 euros at a primary care doctor or online). The result can be documented in Lab2go, together with the context: alcohol in the last 2 weeks, current supplements, last training session.

2. Alcohol break and trend: GGT halves for every 2 to 4 weeks of abstinence. After 6 weeks it becomes visible how far the values drop — that gives a baseline without the alcohol artifact.

3. Medication and supplements: With elevated values, the doctor also checks which medications and supplements are being taken, since GGT responds to medication. Whether NAC, silymarin, or other products come into question is for a doctor to clarify.

4. Follow-up measurement after about 8 weeks: The same panel, with the context documented again. If values remain above 2× the upper limit, medical evaluation is indicated.

For an overview of your own biomarkers, the Biomarker Baseline Checklist offers orientation. The features of Lab2go show how to document all your values over time — and the plans & pricing help you choose the right package.

This article is purely informational and does not replace medical advice, diagnosis, or treatment. Use, dose, and therapy should be clarified with a doctor. If ALT is above 3× the upper limit, you have visible jaundice, or upper abdominal pain, consult a doctor immediately. Supplements cannot replace medication. Ask your doctor or pharmacist if you suspect interactions with existing medication.