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Tool / Longevity

ALT & AST Interpreter.

The "true healthy" ALT limit is lower than what most labs print. Enter your liver enzymes to see your tier against the stricter ACG threshold — and what the AST/ALT ratio hints at.

Healthy ALT upper limit used: 33 U/L

U/L

U/L

The Science

The healthy ALT limit is lower than your lab prints.

ALT (SGPT) and AST (SGOT) are enzymes released when liver cells are stressed or damaged. Many labs still flag ALT only above ~40 U/L, but that legacy limit was derived from populations riddled with undiagnosed fatty liver. The 2017 ACG guideline put the true healthy upper limit near 29–33 U/L for men and 19–25 U/L for women — which is why a "normal" lab ALT can still be mildly elevated by the stricter standard this tool uses.

The AST/ALT (De Ritis) ratio adds context: a ratio below 1 is typical of fatty liver (MASLD), the most common cause of a mild rise, while a ratio of 2 or more points toward alcohol-related injury or advanced fibrosis. Because AST also leaks from muscle, a hard workout shortly before a blood draw can raise it independently of the liver — rest a few days before retesting a borderline value.

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HOMA-IR Calculator →Fatty liver and insulin resistance are two faces of the same metabolic problem.ApoB Interpreter →Metabolic liver disease travels with atherogenic lipoproteins — check the particle count.TDEE Calculator →Losing 7–10% of body weight often normalizes liver enzymes; start with energy balance.
References
  1. Kwo PY, Cohen SM, Lim JK. (2017). ACG Clinical Guideline: evaluation of abnormal liver chemistries. Am J Gastroenterol, 112(1), 18–35.
  2. Botros M, Sikaris KA. (2013). The De Ritis ratio: the test of time. Clin Biochem Rev, 34(3), 117–130.
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