Peptide Unit Converter
mcg, mg, IU — convert between peptide units and calculate concentrations. The math is shown, not hidden.
Unit conversion
500 MCG = 0.5 MG
Concentration calculator
Work out mg per mL from a dose amount and reconstitution volume.
500 mcg/mL
0.5 mg/mL
Research use only — not medical advice. 1 mg = 1,000 mcg. IU values are peptide-specific and come from published pharmacological references; they are not universal. Always verify the conversion factor for your specific preparation.
Quick reference: mcg to mg
The conversions people look up most. These are exact — 1 mg always equals 1,000 mcg.
| Micrograms (mcg) | Milligrams (mg) |
|---|---|
| 100 mcg | 0.1 mg |
| 250 mcg | 0.25 mg |
| 500 mcg | 0.5 mg |
| 1,000 mcg | 1 mg |
| 2,500 mcg | 2.5 mg |
| 5,000 mcg | 5 mg |
| 10,000 mcg | 10 mg |
Common questions
What is an IU (International Unit)?
An International Unit is a standardized measure of biological activity, not a fixed mass. The mcg-to-IU conversion differs for every substance: 1 IU of insulin is a different mass than 1 IU of vitamin D. That is why you must select the specific peptide when converting to or from IU.
How many mcg are in a mg?
1 mg = 1,000 mcg (micrograms). To convert mg to mcg, multiply by 1,000. To convert mcg to mg, divide by 1,000. Mixing these up is a thousand-fold error.
Why is there no universal mcg-to-IU conversion?
IU measures biological effect, not mass. Different compounds have different potencies, so the mass that produces one unit of biological activity varies. Insulin, HCG, vitamin D, and oxytocin each have their own published conversion factor.
How do I calculate concentration (mg per mL)?
Divide the total amount in mcg by the volume in mL. For example, 10 mg (10,000 mcg) in 2 mL = 5,000 mcg/mL = 5 mg/mL. The concentration section below does this for you.