Units? Micrograms? Milliliters? Tick Marks? Frustrated? Calculating accurate peptide doses can be difficult and frustrating. It doesn’t have to be. PepCalc makes peptide calculator math simple.

Public interest in peptide therapy has recently taken off in the wellness space, but the math involved in determining accurate syringe measurements can be confusing to even experienced users and practitioners. It doesn’t have to be.

Quick Note: Peptides are still a “gray” area (they can be sold for research purposes, but legally consumers need a prescription to use them), so I am unable to discuss where or how to purchase. Best to find a practitioner or clinic that offers peptide therapy.

Jeremy (my cofounder at Awesome Labs and fellow biohacker) and I decided to build an app to make it easy for anyone to do calculations (more about our peptide calculator app, PepCalc, in a bit). But first, an overview of peptide dose calculation math…

Peptide Dose Calculation Math

Without getting into the actual math, the problem can be stated as such:

Given a vial containing “X” amount of peptide powder that is then reconstituted in “Y” amount of sterile water, how many units or ticks on a syringe with volume “Z” must I draw the liquid up to in order to reach a desired dose of “D”? 

It’s not rocket science, but it’s far from straightforward!

Peptide Dose Calculation Variables

Let’s take a closer look at the variables that need to be taken into consideration to accurately calculate doses:

1. Desired Peptide Dose

This is the starting point — how much peptide powder (not including the liquid) needs to be in the syringe? Peptide doses are usually measured in micrograms (mcg), but sometimes they may be shown in milligrams (in which case just divide by 1,000 to get micrograms).

Left: U-40 insulin syringes (in units); Right: Tuberculin syringes in mL/cc)

2. Syringe Details (Type, Units, Tick Marks, Volume)

This is where things start to get complicated because syringes come in a number of different configurations:

a. Syringe Type
There are two main types of syringes — tuberculin (non-insulin) and insulin.

Tuberculin (non-insulin) syringes are metric and simply have mL/cc markings reflecting volume.

Insulin syringes are labeled either U-40 or U-100, indicating the type of insulin they are meant to be used with. This is where a lot of confusion arises in the peptide space. U-40 syringes are meant to be used with pre-mixed U-40 insulin vials containing a ratio of 40 units of insulin per 1 mL/cc of water. U-100 syringes are meant to be used with pre-mixed U-100 insulin vials containing a ratio of 100 units of insulin per 1 mL/cc of water. When used with pre-mixed insulin, all unit markings are equal across insulin syringes.

Fun fact: Differing insulin syringes were created to make it easier to dose smaller amounts of insulin. U-40 syringes are considered “canine” syringes and are used for dosing all types of animals.


The peptide dosing confusion stems from the fact that peptide users generally work with insulin syringes but do not have premixed vials of peptide solution.


b. Syringe Volume
There are seven sizes of insulin syringes, ranging in volume from 0.3 mL to 2.0 mL, and tuberculin syringes are typically 0.5 mL or 1.0 mL (but even 2 mL and larger sizes exist).

Left: 1 mL U-100 insulin syringe with 100 tick marks; Right: 1 mL U-100 insulin syringe with 50 tick marks

c. Tick Marks
Tick marks are the lines on the side of the syringe that show increments of units or mL/cc. Like a ruler, there are usually larger lines that indicate major values (10, 20, etc.), and between these lines are one or more smaller equally spaced lines to indicate smaller units (useful when trying to measure precise amounts).

d. Units (Insulin Syringes Only)
While all tuberculin syringes will display tick marks in mL/cc, remember that because insulin syringes are made to inject insulin, the tick marks on insulin syringes represent numbers of units. This is another area that trips most people up — the unit markings will need to be converted to corresponding volume in mL based on whether the syringe is calibrated for U-40 or U-100 insulin. In some cases, insulin syringes will display both units and mL/cc, but tuberculin syringes will not have any units markings.

3. Vial Details

Peptides typically come in a small sealed vial in powder form and must be reconstituted with bacteriostatic (sterile) water before they can be used.

Preparing to add bacteriostatic water to a vial of research peptides

a. Peptide Amount
While the amount of dry peptide in the sealed vial is fixed (measured in milligrams vs. micrograms per dose), the amount of water added will change the dilution and affect how much liquid needs to be drawn from the vial for the same peptide dose (for example, adding 2 mL of water will require twice as much liquid to be drawn, versus adding 1 mL of water, to achieve the same dose).

b. Water Amount
The amount of sterile water added to the vial — typically, more than one syringe full.


Existing Peptide Dose Calculators — Difficult to Use, Sometimes Inaccurate

Jeremy and I started out by making our own spreadsheets to manage calculations. We tried searching for an existing tool that could suit our needs (why re-invent the wheel, right?), and while we did find several web-based calculators, they all had drawbacks — from non-intuitive user interfaces to inflexible or missing options, and in some edge cases would even produce inaccurate results (when we double-checked their math).

Introducing PepCalc — a Simple Peptide Reconstitution and Dose Calculator

If all of this sounds overwhelming, fortunately, there is now an easier way! As I alluded to earlier, we decided to build an app to take all of the headache out of peptide math. It’s called PepCalc, and it’s available on both iOS and Android. We’d love for you to check it out! 👇👇

PepCalc, our peptide calculator app. Available on iOS and Android!

We’re building some cool stuff over at Awesome Labs, a health and wellness technology studio — sign up for our mailing list to get on our early beta user list. 💪

You can also follow Awesome Labs on Instagram and Twitter.

About Bob

Bob Troia is a technology entrepreneur and citizen scientist who is focused on the intersection of data-driven citizen science, health and wellness, human performance, longevity, and self-optimization. He has been featured on CBS News Sunday Morning, PBS NewsHour Weekend, National Geographic Explorer, CBC (Canada), SBS-TV (South Korea), Fast Company, Men's Fitness, Outside Magazine, and on many leading health and wellness podcasts.