How many units do I draw?
Divide the milligrams in the vial by the millilitres of water you added to get the strength in mg/mL. Divide your dose by that strength to get millilitres, then multiply by 100 to get units, because one unit on an insulin syringe is 0.01 mL. So 10 mg in 2 mL is 5 mg/mL, and a 500 mcg dose is 10 units.
The only constant
1 unit
= 0.01 mL
True on every insulin syringe, whatever size the barrel.
How much is in the vial?
Printed on the label, in milligrams
How much water did you add?
Bacteriostatic water, in millilitres
What dose are you taking?
The dose you already intend to use
Which syringe?
Barrel size, printed on the wrapper
Draw to
10 units
on a 0.5 mL insulin syringe (0.1 mL)
- Strength once mixed
- 5 mg/mL
- Doses in the vial
- 20
10 mg in 2 mL makes 5 mg/mL. A 500 mcg dose is 0.1 mL of that, which is 10 units.
This is arithmetic, not advice. It converts a dose you already have into a mark on a syringe. It does not tell you what dose to take. Dosing belongs with a qualified clinician.
A unit is a hundredth of a millilitre. Everything after that is division.
Water does not change your dose. It only decides how far up the barrel that dose lands, which is why adding more of it makes a small dose easier to draw accurately.
Peptide reconstitution chart
Find your vial, then the amount of water you added. Every figure is units on a standard insulin syringe.
| Water added | Strength | 250 mcg dose | 500 mcg dose | 1000 mcg dose |
|---|---|---|---|---|
| 5 mg vial | ||||
| 1 mL | 5 mg/mL | 5 units | 10 units | 20 units |
| 2 mL | 2.5 mg/mL | 10 units | 20 units | 40 units |
| 3 mL | 1.67 mg/mL | 15 units | 30 units | 60 units |
| 10 mg vial | ||||
| 1 mL | 10 mg/mL | 2.5 units | 5 units | 10 units |
| 2 mL | 5 mg/mL | 5 units | 10 units | 20 units |
| 3 mL | 3.33 mg/mL | 7.5 units | 15 units | 30 units |
| 5 mL | 2 mg/mL | 12.5 units | 25 units | 50 units |
| 15 mg vial | ||||
| 3 mL | 5 mg/mL | 5 units | 10 units | 20 units |
| 20 mg vial | ||||
| 2 mL | 10 mg/mL | 2.5 units | 5 units | 10 units |
| 4 mL | 5 mg/mL | 5 units | 10 units | 20 units |
The sum, worked through
- 1
Find the strength
10 mg of powder, 2 mL of water.
10 ÷ 2 = 5 mg/mL
- 2
Find the volume
You want 500 mcg, which is 0.5 mg.
0.5 ÷ 5 = 0.1 mL
- 3
Turn it into units
A unit is a hundredth of a millilitre.
0.1 × 100 = 10 units
Questions people ask
How do I work out peptide units on an insulin syringe?
Divide the milligrams in the vial by the millilitres of water you added. That gives the strength in mg per mL. Then divide your dose by that strength to get the volume in mL, and multiply by 100 to get units, because one unit on an insulin syringe is 0.01 mL. For example, 10 mg in 2 mL is 5 mg/mL, so a 500 mcg dose is 0.1 mL, which is 10 units.
Does adding more water change my dose?
No. The amount of peptide you take stays the same. More water spreads that same amount over more liquid, so you draw to a higher mark on the syringe. That is useful when a dose lands on a mark too small to measure accurately, and it does not change how many doses the vial contains.
How much bacteriostatic water should I add?
There is no single correct amount, because water only decides how far up the barrel your dose lands. Pick the amount that puts your dose on a round, easy-to-read number. The calculator shows you which volume does that.
What does U-100 mean on a syringe?
It means the syringe is marked for U-100 insulin, where 100 units fill 1 mL. So one unit is 0.01 mL no matter which size barrel you have. A 1 mL syringe holds 100 units, a 0.5 mL holds 50, and a 0.3 mL holds 30.
Does this tell me what dose to take?
No. It converts a dose you already have into a mark on a syringe. Choosing a dose is a clinical decision and belongs with a qualified clinician who knows your history.
Doses these are usually studied at
What the published research and clinical use describe, so you have a number to put into the calculator. These are reported ranges, not recommendations, and they are not a substitute for a clinician.
- BPC-157
- 250–500 mcg per day
- Cerebrolysin
- 5–10 mL/day
- CJC-1295
- 100 mcg/injection (no DAC) or 2 mg/week (DAC)
- DSIP
- 100–300 mcg at bedtime
- Epithalon
- 5–10 mg/day
- GHK-Cu
- 1–3 mg/day
- GHRP-2
- 100–300 mcg 1–3x/day
- GHRP-6
- 100–300 mcg 1–3x/day
- Hexarelin
- 100 mcg 1–2x/day (cycled)
- Humanin
- 1–5 mg (estimated)
- IGF-1 LR3
- 20–50 mcg/day
- Ipamorelin
- 200–300 mcg 1–3x/day
- KPV
- 200–500 mcg/day
- LL-37
- 50–100 mcg 2–3x/week
- Melanotan II
- 0.25–0.5 mg (titrate up)
- MOTS-c
- 5 mg 1x/week
- Oxytocin
- 16–40 IU
- PT-141
- 1.75 mg as needed
- Retatrutide
- Trial doses ran from 1 mg to 12 mg weekly, started low and raised gradually
- Selank
- 250–500 mcg 1–3x/day
- Semax
- 200–600 mcg/day
- Sermorelin
- 200–500 mcg nightly
- SS-31
- 5–10 mg/day
- TB-500
- 2–5 mg 2x/week
- Thymosin Alpha-1
- 1.6 mg 2x/week
- VIP
- 50 mcg 1–3x daily
Why is it a range and not a number?
Because the same dose does not land the same way in everyone. Part of that is size, age and what else you take. Part of it is the genes that build the receptors a peptide works through, which differ from person to person and do not change over your lifetime.
The arithmetic on this page is exact. Where you sit inside a range is not, and no calculator can tell you. Reading your own variants is the part we can actually do, and it is worth doing before you settle on a number with a clinician rather than after.