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mg / mcg / IU Conversion Chart for Peptides

Fixed metric conversions between mg, mcg and ng — and why IU is different.

2026-07-23 · 3 min read

Metric mass conversions are fixed. IU (international units) measure biological activity, not mass, so there is no universal mg↔IU conversion. Convert any value with the unit converter.

FromEquals
1 mg1,000 mcg
1 mg1,000,000 ng
1 mcg1,000 ng
0.25 mg250 mcg
0.5 mg500 mcg
2.4 mg2,400 mcg

IU: depends on the substance — use the mg-per-IU factor from your vial or certificate of analysis.

Reference values are approximate and compiled for education only — not medical advice and not dosing guidance. Half-lives and concentrations vary by source, formulation and individual. Always verify against primary literature and your material's certificate of analysis.

For research & education only. These tools convert values you enter. They are not medical advice and do not recommend doses. Peptides referenced are for laboratory research use. Consult a licensed professional for any health decision.

Frequently Asked Questions

How many mcg in a mg?
1 milligram equals 1,000 micrograms. So 0.25 mg is 250 mcg.
Can you convert mg to IU?
Only with a substance-specific factor — IU measures activity, not mass.

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