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Peptide reconstitution calculator.

Turn vial size, water, and your own target amount into the exact syringe units and volume to draw — in one screen.

Educational unit-conversion / reconstitution math only. Works solely from values you enter. It does not recommend any dose, protocol, compound, treatment, sourcing, or personal use — nothing here is medical advice.
Medication (optional — 30+ in library)
Peptide in vial (mg)
Reconstitution water (mL)
Target amount per draw
Syringe
Draw to
10
units
Volume to draw
0.1
mL
At this amount
20
draws / vial
After one draw
4.75
mg left
Syringe · draw to 10 of 100 units
0
10
20
30
40
50
60
70
80
90
100

Each unit on a 100u · 1.0 mL syringe ≈ 25 mcg of this solution.

Concentration
2.5
mg / mL
Concentration
2,500
mcg / mL
Per U-100 unit
25
mcg / unit
Show the math
5 mg × 1000 = 5,000 mcg in the vial
2 mL × 100 = 200 U-100 units of liquid
5,000 mcg ÷ 200 units = 25 mcg per unit
250 mcg ÷ 25 mcg/unit = 10 units
10 units ÷ 100 = 0.1 mL
5,000 mcg ÷ 250 mcg = 20 draws per vial
Compare reconstitution volumes (5mg vial)
Water
mcg / unit
units for 250mcg
1 mL505
2 mL2510
2.5 mL2012.5
3 mL16.6715
5 mL1025

More water → lower concentration → more units for the same amount.

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Get the vial, water, target, and 10-unit draw sent to your inbox so it's easy to reference — and follow when the evidence changes. Free, no account.

U-100 syringe mathFDA-label & USP-referenced unitsHow we review →Human-reviewed editorial process · math cross-checked.

Worked example: 250 mcg from a 10 mg vial

  1. 10 mg × 1000 = 10,000 mcg in the vial.
  2. Add 2 mL water → 2 × 100 = 200 units of liquid. 10,000 ÷ 200 = 50 mcg per unit.
  3. 250 mcg ÷ 50 mcg/unit = 5 units (0.05 mL). The vial holds 40 such draws.

mg vs. mcg vs. IU vs. units

Milligram (mg)Weight of peptide1 mg = 1,000 mcg
Microgram (mcg)Weight of peptide1,000 mcg = 1 mg
International Unit (IU)Biological activityNo mg conversion without a known ratio
Syringe unitVolume drawnU-100: 100 units = 1 mL

Calculator FAQ

Is the calculator free?

Yes — completely free, no account needed. You can optionally email yourself a setup to reference later.

How do I convert mg to syringe units?

The tool converts the peptide weight in your vial into a concentration (mcg per insulin unit) from the water you add, then divides your target amount by that concentration. The full step-by-step is in the calculator's “show the math.”

What's the difference between mg, mcg, IU, and units?

mg and mcg are weight (1 mg = 1,000 mcg). IU is biological activity and does not convert to weight without a known ratio. A syringe “unit” is volume — on a U-100 syringe, 100 units = 1 mL.

Which syringe sizes are supported?

0.3 mL (30 units), 0.5 mL (50 units), and 1.0 mL (100 units).

How much bacteriostatic water should I add?

That's your choice and it changes concentration, not total peptide. Use the compare-volumes table to see how 1, 2, 3, and 5 mL change the units for the same amount.

Does this give medical or dosing advice?

No. It only does arithmetic on values you enter. It never suggests an amount, protocol, or whether anything is safe or advisable. It is not medical advice.

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