Details up front: ApoB · dulaglutide.
I suspect the usual explanation for this is wrong, or at least incomplete.
I am aware this may have a boring answer. I would still like the boring answer stated clearly.
So what is the mechanism, and how well established is it?
Answer first: mild transaminase elevation is common in this population before any drug is involved, and the usual cause is hepatic steatosis rather than anything acute.
Very rapid weight loss can transiently worsen liver biochemistry, which is one of several arguments against pursuing the steepest possible trajectory.
| Quantity | Value | Derivation |
|---|---|---|
| Control-arm event rate | 8.0 % | From the trial table, not the abstract |
| Hazard ratio | 0.80 | Reported |
| Treated event rate | 6.4 % | 8.0 × 0.80 |
| Absolute risk reduction | 1.6 pp | 8.0 − 6.4 |
| Number needed to treat | 63 | 1 ÷ 0.016 |
| Relative risk reduction | 20 % | 1 − 0.80 |
The last two rows describe the same finding. Only one of them is used in headlines.
In practice, gamma-glutamyl transferase is sensitive and unspecific: it rises with alcohol, with several medications and with fatty liver, and an isolated elevation rarely changes anything on its own.
Hy's law and its variants are the standard framework for identifying drug-induced liver injury in trials and are why bilirubin is measured alongside transaminases rather than instead.
Get a baseline before you start anything, because it converts an uninterpretable result into an interpretable one for the cost of one blood draw.
edited 3 Jan 2026 by fib4_reader — reworded for clarity after a comment
Aggregated, published test results and vendor ratings built from submitted batches. Methodology stated, dataset browsable, no listing fees.
Browse resultsThis is one of the areas where the trend across several measurements is far more informative than any single result.
Weight loss of ten per cent or more typically reduces transaminases substantially in people whose elevation was driven by hepatic fat, which is the majority of mild elevations in this population.
Put another way, creatine kinase, alkaline phosphatase and bilirubin together tell you which compartment the abnormality is in, and ordering the transaminases alone throws that information away.
Population data show a substantial fraction of adults with mild transaminase elevation attributable to hepatic steatosis, which sets the base rate against which any new finding should be read.
Read the pattern before the magnitude, and the magnitude in multiples of the upper limit.
Start with the pattern. A hepatocellular pattern with alanine aminotransferase above aspartate aminotransferase points one way; a cholestatic pattern with alkaline phosphatase and gamma-glutamyl transferase points another.
Reference upper limits around forty units per litre for ALT are conventional rather than physiological; several groups have argued for limits closer to thirty for men and twenty-five for women.
On the detail: an isolated result three weeks after starting anything is difficult to interpret. A baseline taken before starting makes the same result trivially interpretable, which is the argument for baselines.
Trials in this class have generally reported improvement rather than deterioration in liver biochemistry, consistent with the weight-mediated mechanism.
Isolated mild elevation is common and usually improves with weight loss.
Before attributing anything to a compound, account for alcohol, muscle injury from new training, and any over-the-counter product being taken alongside.
Alanine aminotransferase is relatively liver-specific; aspartate aminotransferase is also present in muscle, heart and red cells. A raised AST with a normal ALT after heavy resistance training is usually muscle, and creatine kinase settles the question.
Attributing an enzyme change to a compound requires a baseline, and most people asking have not got one.
Transaminases plus bilirubin plus alkaline phosphatase, or you have not measured enough to conclude anything.
The relevant caution is that a rapid rise, particularly with bilirubin, is a different event from a stable mild elevation and needs handling differently.
Hy's law describes the combination that matters: transaminases above three times the upper limit together with bilirubin above twice the upper limit and no cholestatic explanation. That combination is a signal; isolated mild transaminase elevation is not.
Research-use material of unknown content is an unquantifiable variable in any such attribution.
New training, alcohol and over-the-counter products first. Then the interesting hypotheses.
edited 19 Jan 2026 by unit_math — tightened the wording; no substantive change
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.