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PeptideHub

IU to mcg Conversion Calculator for HGH & Peptides

Convert International Units (IU) to micrograms (mcg) for HGH and related compounds. Note: most research peptides (BPC-157, TB-500, Ipamorelin, etc.) are dosed in mcg — not IU. IU dosing applies primarily to human growth hormone (somatropin), where the standard conversion is 1 IU = 333 mcg.

Common research range for BPC-157: 250–500 mcg, 2× daily, subcutaneous. Cycle: 4 weeks on / 2 off.

Educational use only. This calculator performs unit math on the values you provide and is not a substitute for medical advice. Verify every calculation independently.

Result

Concentration
2500 mcg / mL
Per syringe unit
25.00 mcg / unit
Draw to this mark
15.0 units (0.15 mL)
Dose, all units
375 mcg · 0.375 mg
Doses per vial
13.3 doses
Days per vial
6.7 days
Vials needed for 4-week cycle
5 vials

Numbers are computed from your inputs. Verify all calculations independently. Educational use only.

How to Use This Calculator

  1. Confirm the compound uses IU: Verify your compound is dosed in International Units. For most peptides, this only applies to HGH (somatropin). If working with mcg-dosed peptides, use the Peptide Reconstitution Calculator instead.
  2. Enter dose in IU: Input the IU dose from your research protocol. The calculator converts to mcg using the HGH standard of 1 IU = 333 mcg.
  3. Enter vial concentration: Input the IU per vial (e.g., 10 IU/vial or 3.33 mg/vial) and the volume of diluent added to determine the concentration.
  4. Read syringe draw: The calculator returns the draw volume in mL and U-100 units for your IU dose.
  5. Cross-reference with the table: Use the IU → mcg table below to double-check the conversion for common HGH dose points.

Example Calculation — HGH 2 IU Dose

A researcher has a 10 IU HGH vial (equivalent to approximately 3.33 mg) reconstituted with 1 mL BAC water. The protocol calls for a 2 IU dose.

StepCalculationResult
IU → mcg2 IU × 333666 mcg
Vial concentration3,330 mcg ÷ 1 mL3,330 mcg/mL
Volume for dose666 ÷ 3,3300.20 mL
U-100 units0.20 × 10020 units

HGH IU to mcg Reference Table

Standard conversion for 191-amino-acid recombinant somatropin (1 IU = 333 mcg):

HGH Dose (IU)mcg equivalentmg equivalent
0.5 IU166.5 mcg0.167 mg
1 IU333 mcg0.333 mg
2 IU667 mcg0.667 mg
3 IU1,000 mcg1 mg
4 IU1,333 mcg1.333 mg
5 IU1,667 mcg1.667 mg
6 IU2,000 mcg2 mg
10 IU3,333 mcg3.333 mg

IU vs mcg — Which applies to your compound?

CompoundDosed inIU conversion
HGH (somatropin)IU or mg1 IU = 333 mcg
InsulinIUCompound-specific
BPC-157mcgNot applicable
TB-500mcg or mgNot applicable
IpamorelinmcgNot applicable
CJC-1295mcgNot applicable
GHK-CumcgNot applicable

Frequently asked questions

How many mcg is 1 IU of HGH?+

For human growth hormone (HGH / somatropin), 1 IU is approximately equal to 333 mcg (0.333 mg). This is the WHO-defined conversion for 191-amino-acid recombinant HGH. So 2 IU = 667 mcg, 4 IU = 1,333 mcg, and so on.

Are most peptides dosed in IU?+

No. The vast majority of research peptides — BPC-157, TB-500, Ipamorelin, CJC-1295, GHK-Cu, etc. — are dosed in micrograms (mcg), not International Units. IU dosing is primarily relevant for HGH (somatropin) and insulin. Do not assume an IU conversion applies unless the compound explicitly uses IU.

What is an International Unit (IU)?+

An International Unit is a measure of biological activity rather than mass. It is defined by the WHO for each specific compound based on the amount needed to produce a standard biological effect. Because biological activity differs between molecules, there is no universal IU-to-mcg conversion — each compound has its own.

How do I convert IU to units on an insulin syringe for HGH?+

First convert IU to mcg (multiply by 333), then reconstitute your HGH vial and find the concentration in mcg/mL. Divide dose mcg by concentration to get the mL volume, then multiply by 100 for U-100 syringe units. The calculator automates this chain.

What is a typical HGH research dose in IU?+

Preclinical and clinical research protocols for HGH vary widely. Low-dose protocols studied in the literature often range from 1–2 IU/day. Higher doses (4+ IU/day) appear in performance-focused studies. This calculator is for educational reference only — always defer to a licensed physician.

Does the IU conversion differ between brands of HGH?+

The biological definition is standardised at 1 IU = 333 mcg for 191-amino-acid recombinant somatropin. However, some older or lower-purity preparations had different potency. For research-grade recombinant HGH, the 333 mcg/IU figure is the accepted reference.