How do I calculate the concentration of a reconstituted peptide solution?

Divide the vial mass (mg) by the diluent volume (mL) to get mg/mL, then multiply by 1,000 to convert to mcg/mL.

How do I convert mg/mL to micrograms per milliliter for peptide math?

Multiply the mg/mL value by 1,000. For example, 2.5 mg/mL equals 2,500 mcg/mL.

How do I find the dose per unit on a U-100 insulin syringe?

Divide the concentration in mcg/mL by 100. A 2,500 mcg/mL solution delivers 25 mcg per unit.

Peptide Reconstitution Math: Step-by-Step With Worked Examples

Machine-readable facts for this Lab article. The full page is https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step.

TL;DR

Calculate peptide concentration by dividing vial mass in mg by diluent volume in mL, then multiply by 1,000 for mcg/mL. Three worked examples and common errors.

Facts Index

Fact ID	Category	Entity	Attribute	Value	Source
peptide-reconstitution-math-step-by-step:title	identity	Peptide Reconstitution Math: Step-by-Step With Worked Examples	title	Peptide Reconstitution Math: Step-by-Step With Worked Examples	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:published	identity	Peptide Reconstitution Math: Step-by-Step With Worked Examples	published	2026-07-11	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:last-reviewed	identity	Peptide Reconstitution Math: Step-by-Step With Worked Examples	last reviewed	2026-10-03	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:author	identity	Peptide Reconstitution Math: Step-by-Step With Worked Examples	author	Preppin' Peppers Editorial Team	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:topics	identity	Peptide Reconstitution Math: Step-by-Step With Worked Examples	topics	bacteriostatic water, calculator, laboratory hardware, peptide math, reconstitution, research, U-100	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:summary	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	summary	Calculate peptide concentration by dividing vial mass in mg by diluent volume in mL, then multiply by 1,000 for mcg/mL. Three worked examples and common errors.	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-1	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	What It Is	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-2	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	The three quantities you start with	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-3	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Step 1: concentration per milliliter	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-4	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Step 2: concentration per U-100 unit	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-5	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Step 3: draw volume for a given target	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-6	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Worked example 1: 5 mg vial, 2 mL diluent	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-7	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Worked example 2: 10 mg vial, 1 mL diluent	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-8	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Worked example 3: 2 mg vial, 3 mL diluent	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-9	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Reading the three examples side by side	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-10	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Common error 1: unit confusion (mg vs mcg)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-11	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Common error 2: dead volume	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-12	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Common error 3: double conversion	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-13	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	A note on purity	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-14	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	Printable quick-reference formula box	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:section-15	content	Peptide Reconstitution Math: Step-by-Step With Worked Examples	section	What the research community gets wrong about reconstitution math	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:product-gansulin-metal-peptide-pen	products	Peptide Reconstitution Math: Step-by-Step With Worked Examples	references product	Gansulin Pen · Reusable Click-Dial, 3 ml (1-60 Units)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:product-gansulin-3ml-cartridge	products	Peptide Reconstitution Math: Step-by-Step With Worked Examples	references product	Gansulin-Compatible 3 ml Glass Cartridge for Pens (10-Pack)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:source-www-nist-gov	source	Peptide Reconstitution Math: Step-by-Step With Worked Examples	cites	NIST: Metric (SI) Prefixes (milli = 10^-3, micro = 10^-6) - www.nist.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:source-www-nist-gov-2	source	Peptide Reconstitution Math: Step-by-Step With Worked Examples	cites	NIST Guide to the SI, Chapter 6: Rules and Style Conventions for Using Units - www.nist.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)
peptide-reconstitution-math-step-by-step:source-dailymed-nlm-nih-gov	source	Peptide Reconstitution Math: Step-by-Step With Worked Examples	cites	DailyMed (U.S. NLM): HUMULIN R label, concentration 100 units/mL (U-100) - dailymed.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/peptide-reconstitution-math-step-by-step) (evidence)

FAQ

How do I calculate the concentration of a reconstituted peptide solution?: Divide the vial mass (mg) by the diluent volume (mL) to get mg/mL, then multiply by 1,000 to convert to mcg/mL.
How do I convert mg/mL to micrograms per milliliter for peptide math?: Multiply the mg/mL value by 1,000. For example, 2.5 mg/mL equals 2,500 mcg/mL.
How do I find the dose per unit on a U-100 insulin syringe?: Divide the concentration in mcg/mL by 100. A 2,500 mcg/mL solution delivers 25 mcg per unit.