Tools/Unit converter
Peptide unit
converter
The conversions that cause the most errors when reading a study or a certificate of analysis — mg vs mcg, mL vs syringe units, mg/mL vs mcg per unit, IU vs mg — all in one place. Unit arithmetic for educational use only; nothing here is a dosing recommendation.
01 · Mass
mg ↔ mcg
Vial labels are written in milligrams; study doses are often quoted in micrograms. Each step down the ladder (g → mg → mcg → ng) is a factor of 1,000.
Result
5,000mcg
1 mg = 1,000 mcg
Common conversions
- 1 mg1,000 mcg
- 250 mcg0.25 mg
- 1 g1,000 mg
02 · Volume
mL ↔ syringe units
A U-100 insulin syringe is graduated so that 100 units = 1 mL. "Units" here are syringe marks (a volume), not International Units (a biological activity).
1 cc = 1 mL. U-40 and U-50 syringes exist but are not modelled here; check the barrel before reading a mark as U-100.
Result
10units
1 mL = 100 units on a U-100 syringe
U-100 syringe marks
| Volume | Syringe units |
|---|---|
| 0.05 mL | 5 units |
| 0.10 mL | 10 units |
| 0.25 mL | 25 units |
| 0.30 mL | 30 units |
| 0.50 mL | 50 units |
| 1.00 mL | 100 units |
03 · Concentration
mg/mL ↔ mcg per unit
Reconstitution gives a concentration in mg/mL. Dividing by the 100 units in a millilitre turns that into the amount in each syringe mark: 1 mg/mL = 10 mcg per unit. Percent strength is weight per volume: 1% w/v = 1 g per 100 mL = 10 mg/mL.
“Per unit” values assume a U-100 syringe (100 units per mL).
Result
25mcg/unit
1 mg/mL = 10 mcg/unit
Rule of thumb
1 mg/mL = 10 mcg / unit
Percent strength
1% w/v = 10 mg/mL
04 · Somatropin
IU ↔ mg
Somatropin (recombinant human growth hormone) is the one common peptide with a fixed IU-to-mass factor: 3 IU per mg, set by the WHO International Standard 98/574. Enter either side.
Older somatropin lots were calibrated against earlier standards at other ratios; the 3 IU/mg figure is the current WHO reference. Check the certificate of analysis for the lot you are reading.
Result
3IU
1 mg somatropin = 3 IU
Somatropin only. hCG, insulin, EPO and other IU-labelled products are standardised by biological activity against their own reference preparations and have no fixed milligram equivalent, so this converter does not attempt them. Read the IU figure on those labels as-is.
05 · Schedule arithmetic
Amount every N days
Studies describe schedules in different ways — a weekly total, a daily amount, a figure per 28-day cycle. This re-expresses one description as the others so two papers can be compared on the same footing.
Per day
250mcg
Per week
1,750mcg
Per 28 days
7,000mcg
250 mcg ÷ 1 day = 250 mcg per day, then × 7 and × 28.
Pure arithmetic on a schedule described in a study. It is not a dosing recommendation and does not account for half-life or accumulation.
Reference tables
The same factors the converter uses, laid out for reading off the page. All syringe figures assume a U-100 barrel (100 units = 1 mL).
Mass units
Each row is one unit expressed in the others.
| Unit | Grams | Milligrams | Micrograms / nanograms |
|---|---|---|---|
| 1 g | 1,000 mg | 1,000,000 mcg | 1,000,000,000 ng |
| 1 mg | 0.001 g | 1,000 mcg | 1,000,000 ng |
| 1 mcg | 0.000001 g | 0.001 mg | 1,000 ng |
| 1 ng | 0.000000001 g | 0.000001 mg | 0.001 mcg |
U-100 syringe marks
Volume drawn versus the unit graduation on the barrel.
| Volume | Syringe units |
|---|---|
| 0.05 mL | 5 units |
| 0.10 mL | 10 units |
| 0.25 mL | 25 units |
| 0.30 mL | 30 units |
| 0.50 mL | 50 units |
| 1.00 mL | 100 units |
Concentration equivalents
Common reconstitutions and the amount held in each U-100 syringe unit. Peptide in vial ÷ diluent volume = mg/mL; mg/mL × 10 = mcg per unit.
| Reconstitution | Concentration | Per syringe unit |
|---|---|---|
| 5 mg in 1 mL | 5 mg/mL | 50 mcg / unit |
| 5 mg in 2 mL | 2.5 mg/mL | 25 mcg / unit |
| 10 mg in 2 mL | 5 mg/mL | 50 mcg / unit |
| 2 mg in 1 mL | 2 mg/mL | 20 mcg / unit |
Frequently asked questions
How many mcg are in a mg?
1 milligram (mg) equals 1,000 micrograms (mcg). Going the other way, 1 mcg is 0.001 mg, so 250 mcg is 0.25 mg and 500 mcg is 0.5 mg. Vial labels are usually written in mg while study doses are often quoted in mcg, which is why this single factor of 1,000 causes more reading errors than any other.
How many units are in 1 mL on an insulin syringe?
A U-100 insulin syringe is graduated so that 100 units equals 1 mL. Each unit mark is therefore 0.01 mL: 10 units is 0.1 mL, 50 units is 0.5 mL, and a full 1 mL syringe reads 100 units. Other syringe scales (U-40, U-50) exist, so check the barrel before reading a mark as U-100.
What is the difference between syringe units and IU?
They are unrelated. A syringe unit is a volume: one hundredth of a millilitre on a U-100 barrel. An International Unit (IU) is a measure of biological activity defined for a specific substance against a WHO reference preparation. Ten units drawn on an insulin syringe tells you nothing about how many IU are in the syringe until you know the concentration of what is in it.
How do I convert mg/mL to mcg per unit?
Multiply the mg/mL figure by 10. One millilitre holds 100 syringe units, so 1 mg/mL is 1,000 mcg spread across 100 units, or 10 mcg per unit. A vial reconstituted to 2.5 mg/mL contains 25 mcg in every unit mark; at 5 mg/mL each mark holds 50 mcg.
How many IU is 1 mg of HGH (somatropin)?
Under the current WHO International Standard for somatropin (98/574), 1 mg of somatropin is defined as 3 IU, so 1 IU is roughly 0.333 mg. Older reference standards used other ratios, so the factor on a given certificate of analysis should be read from that document. This 3 IU per mg factor applies to somatropin only.
What does % w/v mean?
Weight per volume: grams of solute per 100 mL of solution. A 1% w/v solution contains 1 g in 100 mL, which is 10 mg/mL or 1,000 mcg per 100 units. Percent strength is common on pharmaceutical labels and rare on research peptide vials, which almost always state the total mass in the vial instead.
Why doesn't the converter turn hCG IU into mg?
Because there is no fixed answer. hCG, insulin, EPO and many other biologics are labelled in IU defined by biological activity against their own reference preparations, and the mass that delivers one IU varies by product and purity. Somatropin is the exception because its WHO standard fixes 3 IU per mg. For everything else the IU figure on the label is the figure to use.
Is this medical advice?
No. The converter performs unit arithmetic only. It does not recommend compounds, amounts, or schedules, and nothing on this page should be read as guidance for human or veterinary use. Canada Peptides products are sold for research use only.
Related tools and reading
Next step
From the units to the vial
The dosage calculator turns a vial size and diluent volume into syringe marks; the usage guides cover reconstitution technique, storage, and handling fundamentals.
Disclaimer
This converter performs unit arithmetic only. It does not recommend compounds, amounts, schedules, or protocols, and it does not tell you what dose to use. Canada Peptides compounds are sold for research use only, and nothing on this page is medical advice. Consult a licensed physician before using any peptide compound in any context outside controlled research.