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Works with any peptide

Peptide Reconstitution Calculator

This is the general calculator — it works with any lyophilised research peptide. Enter what is in the vial, how much bacteriostatic water you are adding, and the amount you are measuring for. It returns the concentration, the draw volume in millilitres, and the exact number of units on a U-100 insulin syringe, updating as you type.

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Reconstitution reconstitution calculator

Step 1

Syringe

U-100 insulin
Step 2

Peptide in vial

Step 3

Target amount

Step 4

Bacteriostatic water

Volume to draw
Concentration
Draw volume
Doses / vial

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Quick summary

  • Works with any peptide — enter your own vial size, water volume and target amount.
  • Returns concentration (mg/mL), draw volume (mL) and U-100 syringe units, live.
  • On a U-100 syringe, 100 units = 1 mL. Measurement tool only — it never recommends an amount.
Tool type
Reconstitution + unit calculator
Works with
Any lyophilised peptide
Syringe basis
U-100 · 100 units = 1 mL
Units accepted
mg or mcg
Cost
Free, no signup

What this Reconstitution calculator does

This calculator does one job well: it turns your vial size, the amount of bacteriostatic water you add, and your target amount into a concentration (mg/mL), a draw volume (mL), and the matching units on a U-100 insulin syringe. Change any input and the result updates instantly.

Reconstitution ships as a freeze-dried powder. Before it can be measured into a syringe it has to be reconstituted — dissolved in bacteriostatic water. How much water you add sets the concentration, and the concentration sets how many units each amount works out to. The presets above cover the most common Reconstitution vial setups; use the custom fields for anything else.

Research-use only — not medical advice. This page and calculator are educational measurement and research-planning tools. They do not recommend an amount, diagnose, or treat anything. Products referenced are sold strictly as research chemicals and are not for human or veterinary use.

How to use the Reconstitution calculator

Pick your syringe

Choose the U-100 insulin syringe you'll draw with. Smaller syringes (0.3 mL / 30u) have finer lines, which helps when the draw is small.

Enter your vial and water

Set the milligrams in your Reconstitution vial and the bacteriostatic water you added. Together these set the concentration.

Set your target amount

Toggle mg or mcg and pick (or type) the amount you're measuring for. The calculator does the conversion for you.

Read the draw

The result panel shows concentration, draw volume, and the exact U-100 units to pull, plus how many doses your vial contains.

Reconstitution reconstitution math, explained

The math is short. Concentration = vial size ÷ bacteriostatic water. Draw volume = target amount ÷ concentration. Units = draw volume × 100 (a U-100 syringe reads 100 units per mL). The table below shows common Reconstitution setups and the units for a 1 mg amount at each.

Vial sizeBac waterConcentrationUnits per 1 mg
5 mg1.0 mL5 mg/mL20 units
5 mg2.0 mL2.5 mg/mL40 units
10 mg1.0 mL10 mg/mL10 units
10 mg2.0 mL5 mg/mL20 units
10 mg3.0 mL3.33 mg/mL30 units
20 mg2.0 mL10 mg/mL10 units
30 mg3.0 mL10 mg/mL10 units

Reconstitution amount-to-units reference

How common amounts convert to U-100 syringe units at two example concentrations. These are arithmetic conversions for reference, not a recommendation of any amount.

Units to draw at 5 mg/mL (e.g. 10 mg vial + 2 mL)
AmountVolume (mL)U-100 units
250 mcg0.05 mL5 units
500 mcg0.10 mL10 units
1 mg0.20 mL20 units
2 mg0.40 mL40 units
5 mg1.00 mL100 units (a full syringe)
Units to draw at 10 mg/mL (e.g. 10 mg vial + 1 mL)
AmountVolume (mL)U-100 units
250 mcg0.025 mL2.5 units
500 mcg0.05 mL5 units
1 mg0.10 mL10 units
2 mg0.20 mL20 units
5 mg0.50 mL50 units

Mixing, color & storage tips

The only formula you need

Concentration = vial amount ÷ water added. Draw volume = target amount ÷ concentration. Units = draw volume × 100. Everything here comes from those three lines, which is why the tool shows the intermediate numbers — you can check them by hand.

Pick water for a readable draw

Water volume is the one variable fully under your control. More water means a lower concentration and a larger, easier-to-read draw of the same amount. Aim for 10–40 units; below about 5 units, small reading errors become large percentage errors.

mg and mcg

1 mg = 1000 mcg. Mixing them up is a thousand-fold error and the costliest mistake in this arithmetic. Confirm which unit your reference uses before entering anything, and sanity-check any result that looks extreme.

Mixing and storage

Add water slowly down the inside wall of the vial rather than onto the powder, then swirl gently — never shake. Refrigerate the reconstituted vial, keep it out of light, and do not freeze it.

Reconstitution supplies checklist

A simple reconstitution shopping list. Confirm vial size and batch documentation before you buy.

Reconstitution research vial
COA-verified, third-party tested
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Bacteriostatic water
0.9% benzyl alcohol, for reconstitution
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U-100 insulin syringes
0.3–1.0 mL, for accurate small draws
Any pharmacy
Alcohol prep pads
Sterilize the stopper before each draw
Any pharmacy
Verified USA Supplier
Research peptides research vial
Summit Research Supply Verified

Research peptides

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Reconstitution — frequently asked questions

What does this peptide calculator do?

It converts your vial size, bacteriostatic water volume and target amount into three numbers: concentration in mg/mL, draw volume in mL, and the matching units on a U-100 insulin syringe. It is a measurement tool, not a recommendation.

Is the reconstitution calculator free?

Yes. It runs entirely in your browser, is free, and requires no account or signup.

Does 100 units really equal 1 mL?

On a U-100 insulin syringe, yes. U-100 means 100 units per millilitre, so 1 unit is 0.01 mL and 100 units fills the barrel. That conversion holds regardless of what is in the vial.

How much bacteriostatic water should I add?

Whatever makes your target land on a readable number of units. A 10 mg vial with 2 mL gives 5 mg/mL; with 1 mL it gives 10 mg/mL and halves the units. Try a couple of volumes and use the one that reads cleanest.

Does adding more water give me more doses?

No. Draws per vial equal vial amount ÷ target amount, regardless of water. More water only spreads each draw across more units — it never adds compound.

Does it work with any peptide?

Yes — the arithmetic is universal. For compound-specific reference tables and handling notes, use the per-compound calculators in the Calculators menu.

Is this medical advice?

No. This page is for education and research planning only. It does not diagnose, treat, or recommend an amount. Compounds referenced are sold strictly as research chemicals and are not for human or veterinary use.

For laboratory research use only. PepGuru is an educational tool for measurement, dilution, and reference. Reconstitution and other compounds referenced are sold strictly as research chemicals and are not for human or veterinary use, not drugs, and not intended to diagnose, treat, cure, or prevent any disease. Nothing here is medical advice. Some supplier links are affiliate links and may earn us a commission. This never affects tier placement or review conclusions.
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