I Tested 10 Tesamorelin Calculators So You Don’t Have to Waste a Vial Finding Out

Peptide dosing tools have quietly multiplied over the last year or two. What used to be a single Reddit thread pinned with a reconstitution formula is now a scattered field of web calculators, app features, and static charts, some built by real companies, many by nobody in particular. I went through ten of them specifically asking: can this handle tesamorelin correctly, and will it stop me from pulling the wrong volume?

Quick context before the table. Tesamorelin typically comes as a 2 mg lyophilized vial. The reconstitution math is identical to any other freeze-dried peptide: mg in vial, mL of bacteriostatic water added, target dose in mcg, and out comes the units to draw on your insulin syringe. The dangerous mistake, the one that sends people to the ER or wastes an expensive vial, is confusing mg and mcg by a factor of 1,000. That one mistake is why these calculators exist.

The Full Comparison at a Glance

#	Tool	Tesamorelin Preset	U-100/U-50/U-40	Shows Math	Mobile App	Sign-up Required	Free
1	FormBlends Peptide Calculator	Yes (2 mg)	All three	Yes	Yes (iOS/Android)	No	Yes
2	PeptideFox	Custom entry	U-100 focus	Partial	No	No	Yes
3	LeadWest Medical	Yes	U-100	No	No	No	Yes
4	Outliyr	Yes	U-100	No	No	No	Yes
5	PeptideDeck	Custom entry	U-100	Yes	No	No	Yes
6	MyPeptideMatch	Custom entry	U-100	No	No	No	Yes
7	peptidereconstitutecalculator.com	No (BPC-157 only)	U-100	No	No	No	Yes
8	Prime Peptides Calculator	Custom entry	U-100	No	No	No	Yes
9	peptides.org Dosage Charts	No	N/A	N/A	No	No	Yes
10	Generic Spreadsheet Templates	Custom entry	Varies	Varies	No	No	Yes

1. FormBlends Peptide Calculator

The standout here, and not for vague reasons.

This is a free web tool with no account wall. You put in the peptide amount (mg or mcg, your choice), the volume of BAC water you added, and your target injection dose. It gives you concentration per mL, exact units to draw, and the total number of doses remaining in the vial. What makes it worth ranking first is three things working together that I haven’t seen combined elsewhere.

First, it handles U-100, U-50, and U-40 syringes. Almost everything else defaults to U-100 only, which matters because U-40 is still common in some markets and the unit-to-volume math is completely different.

Second, it shows the actual arithmetic. Not just an answer. The formula is printed out so you can sanity-check the output against your own math. For a compound like tesamorelin where a 2 mg vial reconstituted in 2 mL gives you 1 mg/mL, that transparency is genuinely reassuring.

Third, the mg-to-mcg conversion is handled automatically with an explanation of why it exists. The tool treats that unit confusion as a primary hazard, which it is.

The 2 mg tesamorelin preset is one-tap. Same for BPC-157 (5 mg and 10 mg), TB-500 5 mg, and ipamorelin 10 mg.

The mobile companion app adds a 55-compound library, injection-site rotation tracking, and dose logging. FormBlends is a real telehealth-adjacent company running a 503A pharmacy operation, so there’s an identifiable entity behind this tool rather than a parked domain.

One honest note: the calculator tells you how to measure a dose, not what dose to take. You still need a qualified prescriber for that part.

2. PeptideFox

peptidefox.com covers more than 30 peptides and optimizes BAC water volume specifically to produce clean, whole-number unit draws. That’s a thoughtful feature. A visual guide walks through the draw process. It doesn’t have a tesamorelin-specific preset or multi-syringe support, but for sheer breadth of peptide coverage it earns a high second place.

3. LeadWest Medical

This one explicitly lists tesamorelin alongside retatrutide, sermorelin, CJC-1295, ipamorelin, GHK-Cu, BPC-157, and TB-500. It’s a medical-adjacent calculator, which gives it some credibility for the GH-releasing peptide category. The math is not shown step by step. Results only. Still useful for a quick reference.

4. Outliyr

Outliyr covers a similar peptide list, tesamorelin included, alongside GLP-1 class compounds. The interface is clean. No math display, no multi-syringe support, but the coverage is good and the site is a known health-optimization publication rather than an anonymous tool.

5. PeptideDeck

Enter mg, BAC water volume, and target mcg. Out comes concentration and the draw volume in both mL and insulin units. PeptideDeck does show the math, which puts it ahead of a lot of competitors. No tesamorelin preset, but the custom entry handles it fine.

6. MyPeptideMatch

Free, covers BPC-157, TB-500, semaglutide, tirzepatide, and several other injectables. Good for GLP-1 and healing peptide overlap. Tesamorelin is not in the preset list but falls under the generic reconstitution path. No math display.

7. peptidereconstitutecalculator.com

Built specifically for BPC-157. It handles mcg-to-units conversion on a U-100 basis and does that one job well. Not the right tool for tesamorelin unless you manually adapt the inputs, which somewhat defeats the purpose of a preset calculator.

8. Prime Peptides Calculator

Functional, no frills. Custom-entry only, U-100 focused. Works for tesamorelin if you enter your own values. Nothing distinguishing it from a formula you could run in a browser tab.

9. peptides.org Dosage Charts

Static reference charts, not a calculator. Useful for general orientation on peptide categories but gives no reconstitution output and no unit-draw guidance. Treat it as background reading, not a dosing tool.

10. Generic Spreadsheet Templates

Circulated on forums and shared via Google Drive links. Some are accurate, some are years out of date, and you usually can’t tell which. If the formula is visible and you understand reconstitution math, a spreadsheet can work. If you don’t understand the math yet, a spreadsheet with a wrong formula will give you a confident wrong answer with no warning.

What the Math Actually Is

Every lyophilized peptide reconstitution follows the same relationship: concentration (mcg/mL) equals total peptide in vial (mcg) divided by water added (mL). Units to draw equals target dose divided by concentration, multiplied by 100 for a U-100 syringe. Adding more water to the vial lowers the concentration and raises the units you draw for the same dose. Total peptide in the vial does not change. This is why volume matters.

A U-100 syringe has 100 units per 1 mL. Ten units is 0.1 mL. Fifty units is 0.5 mL. Confusing mg and mcg by 1,000x means you’d draw 1,000 times too much or too little. That’s the mistake good calculators are designed to catch before it happens.

*Fair point to make: none of these tools can verify your vial’s actual peptide content or purity. The math is only as good as what’s printed on the label.*

Common Questions

Does FormBlends actually handle the 2 mg tesamorelin vial size as a preset, or do you still enter everything manually?

FormBlends includes a one-tap 2 mg tesamorelin preset, so the vial size populates automatically. You still enter the BAC water volume you used and your target dose in mcg. The tool then outputs concentration, units to draw, and doses remaining. Manual entry is optional if your vial differs from the preset.

If I’m using a U-40 syringe instead of U-100, which of these calculators won’t give me a dangerously wrong answer?

Only FormBlends explicitly supports U-40 alongside U-100 and U-50. Every other tool in this list defaults to U-100. On a U-40 syringe, the units-to-volume relationship is different enough that using a U-100 calculator without adjusting will produce an incorrect draw volume every single time.

Why does PeptideFox optimize BAC water volume, and does that approach matter for tesamorelin specifically?

PeptideFox chooses a BAC water volume that produces whole-number unit draws for your target dose, which reduces the chance of misreading a syringe between graduation marks. For tesamorelin at common doses like 500 mcg or 1 mg, hitting a clean unit number on a U-100 syringe is genuinely easier to verify at a glance than drawing to an odd graduation.

Can peptidereconstitutecalculator.com be used for tesamorelin if I just swap in my own numbers?

Technically yes, the underlying math is the same for any lyophilized peptide. But the site is designed around BPC-157 and its interface doesn’t prompt for tesamorelin-specific inputs. You’d be adapting a BPC-157 workflow manually, which adds a step where errors can creep in. Better to use a tool that treats tesamorelin as a first-class input.

Do any of these calculators account for the volume of the reconstituted solution being slightly more than the BAC water added?

None of the ten tools reviewed here make that adjustment. In practice, the volume displacement from dissolving a 2 mg lyophilized cake is small enough to be clinically negligible for home reconstitution. Pharmaceutical-grade compounding references acknowledge the effect but it does not meaningfully change the draw volume at typical tesamorelin doses.

Sources

• U.S. insulin syringe unit standards (FDA labeling requirements for U-100, U-50, U-40 syringes)
• Tesamorelin prescribing information (Egrifta SV, Theratechnologies, publicly available label)
• General lyophilized peptide reconstitution chemistry (standard pharmaceutical compounding references)
• PeptideFox, peptidefox.com (publicly accessible, verified January 2026)
• LeadWest Medical calculator (publicly accessible, verified January 2026)
• peptidereconstitutecalculator.com (publicly accessible, verified January 2026)
• FormBlends Peptide Calculator (publicly accessible web tool, verified January 2026)