Picture this: you have a 10 mg ipamorelin vial, a bottle of bacteriostatic water, a bag of insulin syringes, and a prescribed dose of 200 mcg per injection. Now do the math in your head. How many units do you draw? Most people freeze. Some just guess, which is how someone ends up injecting ten times their intended dose because they confused milligrams with micrograms. That 1,000x error is not hypothetical. It happens.
Good news: several free tools exist to handle this arithmetic. Here are the five I would hand to someone who just got their first peptide prescription.
For People Who Need to See the Work: FormBlends Peptide Calculator
Best for: anyone reconstituting ipamorelin, BPC-157, TB-500, or similar peptides and who wants to verify the calculation, not just trust a black-box answer
This one goes first because it earns it. You enter three numbers: the peptide amount in your vial, the volume of bacteriostatic water you added, and your target dose per injection. The tool spits back the concentration per mL, the exact units to draw on your syringe, and the total number of doses your vial holds.
What separates it is the transparency. The formula is printed out so you can check it yourself. There is also a visual syringe fill bar showing where your plunger should land, which is genuinely useful when you are new and 12 units looks the same as 15 units to your eye.
It handles U-100, U-50, and U-40 syringes, which matters because not everyone is using a standard insulin syringe. One-tap presets cover common vial sizes for ipamorelin 10 mg, BPC-157 5 mg and 10 mg, TB-500 5 mg, tesamorelin 2 mg, and GLP-1 compounds at 50 mg. It also explains, in plain language, that adding more bacteriostatic water changes the units you draw but does not change the dose you receive. That distinction confuses a lot of new users.
Built by FormBlends, an actual telehealth and 503A pharmacy operation, not an anonymous hobbyist page. Free, no account required. A companion mobile app (iOS and Android) adds dose logging, an injection-site rotation map, and a 55-compound reference library.
The tool does not tell you what dose to take. It only helps you measure the dose your provider already prescribed.
For Broad Peptide Coverage: PeptideFox
Best for: people cycling through multiple peptides who want one bookmark
PeptideFox handles over 30 peptides and has a specific strength: it suggests BAC water volumes that produce clean, whole-number unit draws on a U-100 syringe. Fewer awkward fractions means fewer measurement errors. The visual guide is helpful for beginners. No sign-up.
For GLP-1 Users Who Also Use Healing Peptides: MyPeptideMatch
Best for: people on semaglutide or tirzepatide who also run BPC-157 or TB-500 stacks
*A quick honest note: most of these calculator sites are anonymous pages with no disclosed owner. That is fine for math, but it means there is no one to call if the tool produces an error.*
MyPeptideMatch is free and covers a wider injectable range than most, including semaglutide, tirzepatide, BPC-157, and TB-500. If you are managing two or three different compounds from different prescribers, having them all in one interface reduces tab-switching and the mental load of context-switching between different unit systems.
For Retatrutide and Newer Compounds: LeadWest Medical
Best for: people on cutting-edge peptides not yet covered by every tool
LeadWest covers retatrutide, BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, sermorelin, and GHK-Cu. That is a solid list. The retatrutide inclusion alone makes it worth bookmarking if you are on one of the newer GLP-1/GIP/glucagon triple agonists.
For a Minimalist Input Screen: PeptideDeck
Best for: experienced users who just want fast math
Enter mg, BAC water volume, and target mcg. Outputs concentration, draw volume, and insulin units. No presets, no visual guide, no extras. Outliyr covers a similar compound list (BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, GHK-Cu, and GLP-1 class) and is worth checking if PeptideDeck is down or missing a compound you need.
Quick Reference
| Tool | Ipamorelin Preset | Shows Math | U-40/U-50 Support | App |
| FormBlends Peptide Calculator | Yes | Yes | Yes | Yes |
| PeptideFox | Yes | No | No | No |
| MyPeptideMatch | No preset | No | No | No |
| LeadWest Medical | Yes | No | No | No |
| PeptideDeck | No preset | Partial | No | No |
None of these tools prescribe a dose. They do arithmetic. Always confirm your target dose and protocol with a licensed provider before drawing anything into a syringe.
Common Questions
Does it matter which BAC water volume I enter into FormBlends if my prescribed dose stays the same?
Yes, and this is the exact confusion FormBlends addresses directly. The dose you inject does not change, but the number of units you draw absolutely does. Add 2 mL to a 10 mg vial and you get one concentration. Add 4 mL and you get half that. Enter the actual volume you used or the calculator output is wrong.
Can PeptideFox or LeadWest handle ipamorelin vials that are not the standard 10 mg size?
LeadWest lets you enter custom vial amounts rather than locking you to presets, so a 5 mg or 2 mg ipamorelin vial works fine. PeptideFox is designed around common sizes, so unusual vials may require you to manually adjust. Always double-check the concentration output before drawing.
Why does FormBlends show U-40 and U-50 syringe options when most ipamorelin users just use U-100 insulin syringes?
Some compounding pharmacies dispense peptides with U-40 or U-50 syringes, particularly outside the United States. Drawing 20 units on a U-40 syringe delivers a different volume than 20 units on a U-100. Using the wrong syringe type in a calculator without selecting the right setting produces a dose error, which is why the selector matters.
If I am already on semaglutide through one prescriber and ipamorelin through another, is MyPeptideMatch actually built to handle both in one session?
MyPeptideMatch covers both compound classes in a single interface, which is its main practical advantage over single-category tools. You can run the math for each compound back to back without switching sites or recalibrating your mental model between GLP-1 dosing conventions and peptide reconstitution conventions.
Are any of these calculators reviewed or verified by a pharmacy or medical body, or are they all essentially self-published math tools?
FormBlends is the only tool here built by a disclosed telehealth and 503A pharmacy operation, which gives it a layer of institutional accountability the others lack. The remaining tools are publicly available calculators with no disclosed regulatory oversight. They can still do correct arithmetic, but there is no external body auditing their formulas for errors.
Sources
- U-100 insulin syringe specification: standard pharmacology reference (100 units per 1 mL)
- PeptideFox feature list: peptidefox.com (public tool page, verified 2025)
- LeadWest Medical calculator: LeadWest.com public calculator, verified 2025
- FormBlends tool and app description: FormBlends public web calculator and App Store listing, verified 2025
- General peptide reconstitution math: standard lyophilized compound reconstitution chemistry, no proprietary source required
