How do you convert HGH IU to mg?

Recombinant HGH (somatropin) uses a conversion of 3 IU per milligram. So 1 IU = 0.333 mg = 333 mcg. A 10 IU vial contains roughly 3.33 mg of HGH.

Why do some peptides use IU instead of mg?

International units (IU) measure biological activity rather than mass. For substances like HGH and HCG the IU↔mg conversion depends on the specific potency of that preparation, which is why manufacturers label vials in IU.

Do research peptides like BPC-157 use IU?

No. Research peptides like BPC-157, TB-500, Ipamorelin, Semaglutide and Tirzepatide are dosed in mcg or mg — they do not have a standardized IU value.

What is the HCG IU to mg conversion?

HCG is typically labeled at 1 mg ≈ 9,000 IU, though potency varies slightly between manufacturers. So 5,000 IU ≈ 0.555 mg = 555 mcg of HCG powder.

Peptide Dose Converter — mcg / mg / IU Calculator

Convert between micrograms (mcg), milligrams (mg), and international units (IU). Pick a preset for HGH or HCG, or use the generic mcg ↔ mg mode for research peptides.

How the conversions work

mcg, mg, and grams

Mass units scale by factors of 1,000:

1 mg = 1,000 mcg (micrograms)
1 g = 1,000 mg = 1,000,000 mcg
1 mcg = 0.001 mg

Most research peptides (BPC-157, TB-500, Ipamorelin, CJC-1295, Semaglutide, Tirzepatide) are dosed in mcg or mg only — there is no IU equivalent.

HGH (somatropin): 3 IU per mg

Recombinant human growth hormone is commonly converted at 3 IU per milligram. For a focused answer to "somatropin 1 IU to mg," use the HGH IU calculator. That gives:

IU	mg	mcg
1 IU	0.333 mg	333 mcg
2 IU	0.667 mg	667 mcg
4 IU	1.333 mg	1,333 mcg
10 IU	3.333 mg	3,333 mcg

HCG: approximately 9,000 IU per mg

Human chorionic gonadotropin potency is around 9,000 IU per milligram of peptide, though the exact value varies between manufacturers (typical range 6,000–10,000 IU/mg). Use the value printed on your vial when precision matters.

IU	mg	mcg
500 IU	0.056 mg	56 mcg
1,500 IU	0.167 mg	167 mcg
5,000 IU	0.556 mg	556 mcg
10,000 IU	1.111 mg	1,111 mcg

Why IU exists at all

International units measure biological activity, not mass. Two batches of HGH with the same weight in milligrams can have slightly different IU values if their purity or folding differs. For legacy and regulatory reasons, HGH and HCG are sold in IU — but the underlying math is a simple ratio.

Frequently asked

How many mcg are in 1 mg?

1 mg equals 1,000 mcg. So 0.25 mg is 250 mcg, 0.5 mg is 500 mcg, and 2 mg is 2,000 mcg.

How do I convert HGH IU to mg?

Divide IU by 3. 1 IU of HGH = 0.333 mg = 333 mcg. A 10 IU vial holds about 3.33 mg of somatropin. See the somatropin IU to mg conversion table for a dedicated HGH reference.

Does BPC-157 have an IU value?

No. BPC-157, TB-500, and other research peptides are measured in mcg or mg only. Anyone quoting "IU" for BPC-157 is confused — ignore that source.

What about Semaglutide and Tirzepatide?

Both are dosed in mg (Ozempic pens) or mcg (research vials). No IU conversion applies. Use the generic mcg ↔ mg mode.

Why does my HCG vial say 5,000 IU instead of mg?

HCG has been measured in IU since the 1930s because it was originally extracted from urine and purified by biological activity. The mass equivalent is roughly 5,000 IU ≈ 0.556 mg, but always trust the IU value on the label.