Peptide Units Converter
Convert between mg, mcg, syringe units, IU, and ml. Four modes, one tool. Enter a value, get the result instantly.
Reviewed by the Klarovel Medical Advisory Board. Last updated . Primary sources are cited below.
Save your conversion. Get the protocol behind it.
We'll send your reconstitution and a link to get your protocol: $99 one time. Previously $179 a year.
Common conversions, answered
Mass to syringe units always depends on concentration, so each answer below is given at the four concentrations you get from the usual vial and water combinations. Use the converter above for any figure not listed here.
500 mcg to units
Also searched as: 500mcg to units, 500mcg to units syringe
500 mcg is 20 units on a U-100 insulin syringe at 2.5 mg/ml, which is the concentration you get from a 5 mg vial reconstituted with 2 ml of bacteriostatic water. There is no single answer without the concentration: 500 mcg is 0.5 mg, and 0.5 mg divided by the concentration gives the volume in ml, which times 100 gives the units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 50 units (0.50 ml) |
| 2.5 mg/ml (5 mg + 2 ml) | 20 units (0.20 ml) |
| 5 mg/ml (5 mg + 1 ml) | 10 units (0.10 ml) |
| 10 mg/ml (10 mg + 1 ml) | 5 units (0.05 ml) |
- Formula: units = (0.5 mg / concentration in mg/ml) x 100.
- The syringe barrel size does not change the answer. A 30-unit, 50-unit, and 100-unit syringe all use 1 unit = 0.01 ml.
100 mcg to units
Also searched as: 100mcg to units
100 mcg is 4 units on a U-100 insulin syringe at 2.5 mg/ml. 100 mcg is 0.1 mg, so 0.1 mg divided by 2.5 mg/ml is 0.04 ml, which is 4 units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 10 units (0.10 ml) |
| 2.5 mg/ml (5 mg + 2 ml) | 4 units (0.04 ml) |
| 5 mg/ml (5 mg + 1 ml) | 2 units (0.02 ml) |
| 10 mg/ml (10 mg + 1 ml) | 1 unit (0.01 ml) |
- At 10 mg/ml a 100 mcg dose lands on a single unit mark, which leaves no room for a measurement error. A lower concentration (more water) gives you more markings to aim at.
5 mg to units
Also searched as: 5mg to units
A 5 mg vial reconstituted with 1 ml of bacteriostatic water fills exactly 100 units, so the whole vial is one full 100-unit syringe and 1 unit is 0.05 mg (50 mcg). Add more water and the same 5 mg spreads across more units.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml (5 mg + 5 ml) | 500 units total (1 unit = 10 mcg) |
| 2.5 mg/ml (5 mg + 2 ml) | 200 units total (1 unit = 25 mcg) |
| 5 mg/ml (5 mg + 1 ml) | 100 units total (1 unit = 50 mcg) |
| 10 mg/ml (10 mg + 1 ml) | 50 units per 5 mg (1 unit = 100 mcg) |
- A 1 ml insulin syringe holds 100 units. Anything above 100 units is more than one syringe, not a bigger draw.
- 5 mg is the vial size, not the dose. It is the total peptide in the vial, spread across however many doses your protocol splits it into.
100 mg to units
100 mg is 100 units only when the solution is 100 mg/ml, because 100 units is 1 ml on a U-100 syringe. At any other concentration the answer changes: divide 100 mg by the concentration to get ml, then multiply by 100.
| Concentration (vial + water) | Result |
|---|---|
| 10 mg/ml | 1,000 units (10 ml) |
| 50 mg/ml | 200 units (2 ml) |
| 100 mg/ml | 100 units (1 ml) |
| 200 mg/ml | 50 units (0.5 ml) |
- 100 mg is far above any peptide dose on this site. Peptide doses are typically measured in mcg or single-digit mg. If a protocol reads 100 mg, re-read the units before drawing anything.
units to mg
Also searched as: units in mg, units/mg
mg = (units divided by 100) times the concentration in mg/ml. One unit on a U-100 insulin syringe is always 0.01 ml, so at 2.5 mg/ml a single unit is 0.025 mg, which is 25 mcg.
| Concentration | What 1 unit is worth |
|---|---|
| 1 mg/ml | 0.01 mg (10 mcg) |
| 2.5 mg/ml | 0.025 mg (25 mcg) |
| 5 mg/ml | 0.05 mg (50 mcg) |
| 10 mg/ml | 0.1 mg (100 mcg) |
- There is no fixed units-per-mg ratio. Units measure volume on the syringe; mg measures mass. The concentration is the only thing that connects them.
- Concentration = vial size in mg divided by the millilitres of bacteriostatic water you added.
10 units to mg
10 units is 0.25 mg (250 mcg) at 2.5 mg/ml. 10 units is 0.1 ml on any U-100 syringe, and 0.1 ml times the concentration gives the dose.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.1 mg (100 mcg) |
| 2.5 mg/ml | 0.25 mg (250 mcg) |
| 5 mg/ml | 0.5 mg (500 mcg) |
| 10 mg/ml | 1 mg (1,000 mcg) |
20 units to mg
20 units is 0.5 mg (500 mcg) at 2.5 mg/ml. 20 units is 0.2 ml on any U-100 syringe, and 0.2 ml times the concentration gives the dose.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.2 mg (200 mcg) |
| 2.5 mg/ml | 0.5 mg (500 mcg) |
| 5 mg/ml | 1 mg (1,000 mcg) |
| 10 mg/ml | 2 mg (2,000 mcg) |
50 units to mg
50 units is 1.25 mg at 2.5 mg/ml. 50 units is 0.5 ml on any U-100 syringe, which is half of a 1 ml syringe or a full 0.5 ml syringe.
| Concentration (vial + water) | Result |
|---|---|
| 1 mg/ml | 0.5 mg (500 mcg) |
| 2.5 mg/ml | 1.25 mg (1,250 mcg) |
| 5 mg/ml | 2.5 mg (2,500 mcg) |
| 10 mg/ml | 5 mg (5,000 mcg) |
IU to mg conversion calculator
IU does not convert to mg by a universal factor, so no single calculator covers every substance. IU measures biological activity and mg measures mass, and the ratio between them is set per substance by a reference standard. For somatropin (HGH) the standard is 1 mg = 3 IU, so mg = IU divided by 3.
- Use the converter at the top of this page for mg, mcg, ml, and syringe units, which are pure arithmetic.
- For an IU conversion, find the reference ratio for that specific substance first, then apply it. Applying the HGH ratio to a different molecule gives a wrong number.
How many IU in a mg
For HGH (somatropin) there are 3 IU in 1 mg. For anything else the answer is different, because IU is defined per substance against its own reference preparation, not by weight.
| HGH in mg | IU |
|---|---|
| 1 mg | 3 IU |
| 2 mg | 6 IU |
| 4 mg | 12 IU |
| 5 mg | 15 IU |
| 10 mg | 30 IU |
How many mg in an IU
For HGH (somatropin) 1 IU is 0.33 mg, which is 333 mcg. Divide the IU figure by 3 to get milligrams. As above, the ratio is substance-specific and does not carry over to other molecules.
| HGH in IU | mg |
|---|---|
| 1 IU | 0.33 mg (333 mcg) |
| 2 IU | 0.67 mg (667 mcg) |
| 4 IU | 1.33 mg |
| 10 IU | 3.33 mg |
| 30 IU | 10 mg |
HGH mg to IU
Multiply HGH milligrams by 3 to get IU: 1 mg is 3 IU, 5 mg is 15 IU, 10 mg is 30 IU. To go the other way, divide IU by 3.
- HGH vials are usually labelled in IU, while the reconstitution math runs in mg. Convert to mg first, then work out syringe units from the concentration.
- Worked example: a 10 IU vial is 3.33 mg. Reconstituted with 1 ml that is 3.33 mg/ml, so a 1 IU dose (0.33 mg) is 0.1 ml, which is 10 units.
Every figure above assumes a U-100 insulin syringe, where 1 unit is 0.01 ml. Check your syringe: a U-40 syringe uses a different scale and the numbers will not transfer. These conversions are arithmetic, not dosing advice. Klarovel builds protocols from your health data and does not sell, source, or ship peptides.
Quick reference
The six conversions you encounter most often when working with peptides. Every one reduces to a single multiply or divide.
mg → mcg
× 1,000
0.25 mg = 250 mcg
mcg → mg
÷ 1,000
500 mcg = 0.5 mg
ml → units
× 100
0.1 ml = 10 units
units → ml
÷ 100
25 units = 0.25 ml
mg → IU
× 3
1 mg ≈ 3 IU
IU → mg
÷ 3
6 IU ≈ 2 mg
U-100 insulin syringe sizes
All three sizes use the same standard: 1 unit = 0.01 ml. The math never changes. Only the maximum capacity differs.
| Syringe | Capacity | Max units | Best for |
|---|---|---|---|
| 0.3 ml | 0.3 ml | 30 | Small doses under 30 units. Finest markings. |
| 0.5 ml | 0.5 ml | 50 | Moderate doses between 30-50 units. |
| 1.0 ml | 1.0 ml | 100 | Large doses or loading protocols up to 100 units. |
How peptide unit conversion works
Peptide doses are prescribed in weight (mg or mcg), but you measure them in syringe units. The bridge between the two is concentration, expressed as mg/ml.
Concentration is set during reconstitution: divide the total peptide in the vial by the volume of water you added. A 5 mg vial with 2 ml of BAC water gives you 2.5 mg/ml.
Once you know the concentration, every conversion is the same two steps. To go from dose to units: divide the dose (mg) by the concentration (mg/ml) to get ml, then multiply by 100 for units. To reverse it, divide units by 100 to get ml, then multiply by the concentration.
Forward: units = (dose_mg ÷ concentration) × 100
Reverse: dose_mg = (units ÷ 100) × concentration
Example: 250 mcg at 2.5 mg/ml → (0.25 ÷ 2.5) × 100 = 10 units
Common questions
Units, mass, volume, and how they relate.
Sources
The arithmetic is ours. The constants and dose schedules it relies on are not ours to assert, so these are the primary documents behind them, retrieved 2026-09-25.
- Bacteriostatic Water for Injection, USP (Hospira), prescribing label. DailyMed, U.S. National Library of Medicine.
Bacteriostatic water is sterile water with 0.9% benzyl alcohol, supplied in a multiple-dose container for repeated withdrawals to dissolve drugs for injection.
- Humulin R U-100, prescribing information. DailyMed, U.S. National Library of Medicine.
U-100 means 100 units per ml, and a U-100 dose must be measured with a syringe marked for U-100. This is the conversion behind step 3 of the formula.
- BD Insulin Syringe, 510(k) K190054 summary. U.S. Food and Drug Administration.
The syringes are intended for U-100 insulin and come in 1 ml, 0.5 ml and 0.3 ml capacities, the three barrel sizes the unit counts on this page apply to.
Go beyond the calculator
Your health profile, your protocol.
The Klarovel engine maps your questionnaire and goals against a 41-peptide catalog, resolves contraindications, calibrates dosing, and sets the cycling schedule. Safety-checked by the Klarovel engine before delivery.
$99 one time. Previously $179 a year. No subscription.