Free Peptide Dosage Calculator – Exact Syringe Units from Concentration or Body Weight

Last updated August 2026 · Free · No signup required · Mobile-friendly

Use this free peptide dosage calculator when you already know your concentration (or want to calculate dose by body weight). Enter your target dose and concentration to get the precise volume and insulin syringe units to draw. Perfect for daily or weekly protocols once your vial is reconstituted.

Two calculation modes explained

Fixed Dose mode is the most common. You already know exactly how many micrograms or milligrams you want to administer (for example 250 mcg of BPC-157 or 2.5 mg of Tirzepatide). Enter that dose and your current concentration and the calculator returns the exact volume and units to draw.

Body-Weight mode is useful for peptides that are typically dosed in mcg per kilogram of body weight (many research growth-hormone secretagogues and some healing peptides). Enter your weight, the mcg/kg dose, and concentration — the tool first calculates the total micrograms needed, then converts it to syringe units.

How the dosage math works

Once concentration is known, the conversion is straightforward:

Body-weight dosing – when and why it is used

Some research peptides are traditionally dosed relative to body weight rather than as a flat microgram amount. This approach aims to produce more consistent blood levels across different body sizes. Common examples in the research literature include certain GHRPs and growth-hormone releasing hormones.

When using body-weight mode:

• Always confirm the mcg/kg figure with your protocol or clinician.
• Use accurate current body weight (not an estimate).
• Re-calculate if body weight changes significantly over a longer protocol.

Common concentration values after reconstitution

• 5 mg peptide + 2 mL BAC water → 2.5 mg/mL
• 10 mg peptide + 2 mL BAC water → 5 mg/mL
• 5 mg peptide + 1 mL BAC water → 5 mg/mL
• 10 mg peptide + 1 mL BAC water → 10 mg/mL

These are the most frequently used starting points. The Dosage Calculator lets you plug in any custom concentration you actually prepared.

Choosing the right syringe for accurate dosing

Smaller barrel syringes (0.3 mL and 0.5 mL) give finer marks and are preferred when the calculated volume is under ~0.25 mL (25 units). A 1 mL syringe remains the most versatile choice for doses between 10–80 units.

Frequently Asked Questions

Free peptide dosage calculator · No registration · Updated August 2026