Tools

Peptide calculator

Vial size, bacteriostatic water, your intended dose - and this page returns the concentration, the draw volume, and the exact units on a U-100 insulin syringe. Every peptide calculator you will find in search belongs to a company selling peptides. This one belongs to a regulatory-status reference thatsells nothing - the math has no thumb on the scale.

Peptide reconstitution calculator

Math on the numbers you enter - nothing more. Peptlas sells nothing and suggests no amounts.

Enter your intended dose above and the draw appears here, with the math shown.

Results are arithmetic, not advice. Peptlas is a regulatory-status reference: it does not recommend amounts, schedules, or use of any compound. Read the full disclaimer.

The math, shown once

Reconstitution is the step where a freeze-dried (lyophilized) peptide powder is dissolved in bacteriostatic water. The arithmetic that follows trips people up because three unit systems collide: the vial is labeled in milligrams, doses are discussed in micrograms, and syringes are marked in insulin units. The whole calculation is two divisions:

  1. Concentration = vial contents ÷ water added. A 5 mg vial is 5,000 mcg; add 2 ml of water and every milliliter holds 2,500 mcg.
  2. Draw = dose ÷ concentration. Suppose a dose of 250 mcg: 250 ÷ 2,500 = 0.1 ml. A U-100 syringe marks 100 units per ml, so 0.1 ml sits at the 10-unit line.

The water amount is a free choice - it changes the concentration, never the amount of peptide. More water makes the same dose a larger, easier-to-read draw. That is the entire lever, and it is why no single "correct" water volume exists for any vial.

Calculators by compound

Each compound page pre-loads its commonly sold vial sizes, works the math with that compound's numbers - and shows where it currently stands with U.S. regulators, because that context is what this site exists to give.

Questions people actually ask

How do you calculate peptide reconstitution?
Two steps of arithmetic. First, concentration: the vial amount in micrograms divided by the water added in milliliters (a 5 mg vial is 5,000 mcg; with 2 ml of bacteriostatic water that is 2,500 mcg/ml). Second, draw volume: your dose in micrograms divided by that concentration (250 mcg at 2,500 mcg/ml is 0.1 ml). On a U-100 insulin syringe, milliliters times 100 gives the units to draw - 0.1 ml is 10 units.
How many units is my dose on an insulin syringe?
Units = (dose in mcg ÷ concentration in mcg/ml) × 100, because a U-100 syringe marks 100 units per milliliter. The calculator on this page does the conversion and shows the draw on a 100-unit scale.
How much bacteriostatic water should I add to a peptide vial?
Mathematically, any amount - water changes the concentration, not how much peptide is in the vial. More water means a lower concentration, so the same dose becomes a larger, easier-to-measure draw; less water means a smaller draw. The practical constraint is that the full draw for your dose should land at a readable line on your syringe. This site reports regulatory status and does the math; it does not recommend amounts.
Why does this calculator not suggest doses?
Peptlas is a neutral regulatory-status reference. It sells nothing, takes no money from vendors, and makes no health claims - that neutrality is the reason to trust its numbers. Dosing is a decision between a person and a licensed clinician; this tool only converts the numbers you already have into syringe units.
What is a U-100 insulin syringe?
A syringe marked in insulin units where 100 units equal 1 milliliter - the most common syringe used to measure small liquid amounts. Every result on this page shows both milliliters and U-100 units, so the math works for any syringe.

The question behind the question

Most people doing this math have a quieter question underneath it: where does this compound actually stand with regulators? That answer changes - an FDA advisory committee voted on seven peptides in July 2026, and rulemaking is in motion for several more. The atlas keeps a dated, source-linked answer for every compound it tracks:

BPC-157: In limboTB-500 (Thymosin Beta-4): In limboSemaglutide: RestrictedTirzepatide: RestrictedRetatrutide: RestrictedIpamorelin: In limbo

Plus 12 more compounds on the full atlas, each verified by hand (most recently Aug 11, 2026 (ET)), with every change logged andthe method public.