What's an optimal fasting insulin level?

Metabolic-health practitioners aim for roughly 2–6 µIU/mL, well below the wide lab reference range of about 2–25. That optimal target is evidence-informed rather than a formal guideline number — no major body publishes one — so treat it as a direction, not a hard cutoff.

My lab says my insulin is 'normal' — why does this tool flag it?

The lab reference range (about 2–25 µIU/mL) describes the population walking through the door, which is largely insulin-resistant. 'In range' is not the same as optimal. This tool compares your number against the optimal zone, so a value the lab calls normal can still read as above-optimal here.

How do I convert pmol/L to µIU/mL?

Roughly divide pmol/L by 6 to 7. The exact factor is contested (both 6.0 and 6.945 are used) and assay-dependent, so don't trust a converter to the decimal — compare against the reference range printed on your own report.

Tool

Is your fasting insulin optimal, or just “lab-normal”?

Your lab grades your insulin against a wide range built from a largely insulin-resistant population — so an above-optimal number comes back “normal.” This tool resolves your actual value against the optimal zone, adds your HOMA-IR if you have a fasting glucose, handles the µIU/mL ↔ pmol/L mess, and adjusts for keto and PCOS.

Fasting insulin

Fasting glucose (optional)

Add it to unlock your HOMA-IR

Any of these apply? (optional)

Enter your fasting insulin to see where it lands against optimal — not just the wide “lab-normal” range. Add fasting glucose to get your HOMA-IR too.

For the full picture — whether to test, which test, and what actually lowers insulin (ranked honestly), see the fasting insulin guide.