ALP — Liver and Bone in One Number
Alkaline phosphatase is concentrated in the liver, the bile ducts and the bones — which is exactly what makes a raised value ambiguous until you know which of the three it came from.
Alkaline phosphatase is an enzyme concentrated in the liver, the bile ducts and the bones — which is exactly what makes a raised value ambiguous until you know which of the three it came from.
The biomarker
- Name: Alkaline Phosphatase (ALP)
- Units: U/L
- Standard range: 20–130 U/L (varies between laboratories)
- Optimal range: no separate "optimal" band is published; interpret within the reference range against your own history
How to read your result
| Pattern | What it points to |
|---|---|
| Raised alongside ALT, AST or bilirubin | Points toward the liver or a bile-duct obstruction |
| Raised with normal liver enzymes | More often points to bone turnover — growth, a healing fracture, or a bone condition |
| Source unclear | An ALP isoenzyme test separates the liver fraction from the bone fraction |
| Low | Uncommon; can relate to malnutrition or specific rare conditions — a clinical question, not a self-assessed one |
| Physiologically higher | ALP is normally higher in adolescents and in pregnancy |
What moves the needle
- Never read it alone. ALP is interpreted alongside ALT, AST, GGT and bilirubin.
- If it is raised, a GGT drawn at the same time helps separate liver from bone: GGT rises with liver-source ALP, not with bone-source.
- Alcohol: reduce or pause it before a repeat draw if liver markers are the question.
- Referral: a persistently raised ALP is a clinician's question — the follow-up test depends on which fraction is elevated.
- Never treat a raised ALP with a supplement.
Why this test is worth asking for
- It already sits on the standard comprehensive metabolic panel, so it usually costs nothing extra to read properly.
- It is one of the few routine values that reports on two unrelated systems at once — which is a strength when it is read in context and a trap when it is read alone.
- Read together with GGT and ALT and AST, it turns an ambiguous number into a direction.
Sources
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
