Last month a friend texted me a photo of his tesamorelin vial, a bottle of BAC water, and a panicked message: “I have 2mg in this vial, I added 2mL of water, I’m supposed to take 333mcg, what do I draw?” He had a U-100 syringe, a decent scale, and absolutely no idea what to do with the math. This list exists for that moment.

Tesamorelin comes lyophilized. You add bacteriostatic water, do the concentration math, convert micrograms to syringe units, and draw accordingly. Mess up the mg-to-mcg conversion by a factor of 1000 and you have a serious problem. These calculators eliminate that error.

1. FormBlends Peptide Calculator

What sets it apart is not flash, it is transparency. The tool shows you every step of the arithmetic so you can actually verify the output rather than just trust a black box. You enter your vial size, how much BAC water you added, and your target dose per injection. It tells you the resulting concentration, the exact units to draw, and how many doses you have left in the vial.

It handles U-100, U-50, and U-40 syringes. It has a one-tap preset for tesamorelin 2mg, the standard vial size, which saves time and reduces input errors. A visual syringe bar shows exactly where to stop pulling the plunger. The mg-to-mcg conversion happens automatically, because that 1000x mistake is the most common one people make.

Built by a real company running a 503A compounding pharmacy. No login required. Works in a browser or inside their iOS/Android app, which adds dose logging and an injection-site rotation map. Free either way.

My honest take: for tesamorelin specifically, the 2mg preset plus the shown math makes this the safest starting point I know of.

2. PeptideFox

peptidefox.com supports over 30 peptides and adds something genuinely useful: it helps you choose a BAC water volume that produces clean, whole-number unit draws. Small thing. Enormous practical difference when you are pulling 16.5 units at midnight.

3. LeadWest Medical

A clinical-looking calculator with explicit tesamorelin support alongside sermorelin, ipamorelin, CJC-1295, BPC-157, TB-500, and GHK-Cu. Feels more like something a provider’s office would link to than a hobbyist page. Good for people who want a second confirmation number.

4. Outliyr

Covers the same peptide family as LeadWest and adds GLP-1 class compounds. The interface is clean. Worth bookmarking if you are running more than one peptide protocol at once and want everything in the same place.

5. PeptideDeck

Enter milligrams of peptide, milliliters of BAC water, and your target dose in micrograms. It outputs concentration per mL, draw volume in mL, and the equivalent insulin units. Direct and no-frills. Good backup calculator when you want to cross-check a number from another tool.

*(Quick honesty note: most of these are anonymous web pages with no named company behind them. Treat them as math aids, not medical authorities.)*

6. MyPeptideMatch

Free, covers BPC-157, TB-500, semaglutide, tirzepatide, and other injectables. The GLP-1 coverage alongside peptides is useful if your protocol mixes compound types.

7. peptidereconstitutecalculator.com

Built specifically around BPC-157 on U-100 syringes, mcg-to-units conversion. Narrow focus, but that narrowness means the instructions are unusually clear for beginners. The reconstitution math is the same for tesamorelin, so the logic transfers even if the presets do not.

8. peptides.org Dosage Charts

Not an interactive calculator. Static reference charts. Still worth having open because they give you a sanity-check range before you start punching numbers into any tool.

9. Prime Peptides Calculator

Straightforward reconstitution tool. Less documented than the others in terms of who maintains it, but the core concentration math it uses is the same as everything else on this list, because there is only one way to do that math.

10. Pencil and the Formula Itself

(dose in mcg / concentration in mcg per mL) x 100 = units to draw on a U-100 syringe. Knowing this means no calculator can ever mislead you without you catching it. Every tool on this list is just a wrapper around those operations.

Whatever you use, get your dose from a qualified prescriber first. These tools measure. They do not prescribe.

Common Questions

Why does the FormBlends calculator show a tesamorelin 2mg preset when other tools make you enter everything manually?

FormBlends is built by a 503A compounding pharmacy, so 2mg is the vial size they actually dispense. Presets tied to real dispensing practice reduce input errors. That said, always confirm your specific vial size before accepting any preset, because compounders do occasionally supply other concentrations.

If PeptideFox supports over 30 peptides, does it handle the specific mcg-to-units math tesamorelin requires, or is it generic?

It handles the same underlying math every peptide on this list uses: divide your dose in mcg by the concentration in mcg per mL, then multiply by 100 for U-100 syringes. PeptideFox adds the practical step of suggesting BAC water volumes that produce whole-number draws, which matters when your target dose is something like 333mcg from a 2mg vial.

Can I use peptidereconstitutecalculator.com for tesamorelin even though it was built around BPC-157?

Yes, with one condition. The reconstitution formula is identical for both peptides. What will not transfer are any BPC-157-specific presets or default dose ranges. Enter your actual tesamorelin vial size, your BAC water volume, and your prescribed dose manually, and the math output will be correct.

What is the real risk of skipping a calculator and doing the conversion in my head?

The mg-to-mcg conversion is a factor of 1000. A 2mg vial contains 2000mcg, not 2mcg. People who skip the calculator and misplace that decimal can draw a dose that is 10 times too high or too low. Neither outcome is trivial. The formula in entry 10 takes about 20 seconds on a phone calculator and catches that error every time.

Do any of these tools store my dose history, or are they all single-session calculators?

Most are single-session only, including PeptideDeck, LeadWest, and PeptideFox. FormBlends is the exception on this list: its iOS and Android app adds dose logging and injection-site rotation tracking across sessions. If keeping a record matters to you, that is the only option here that does it natively.

Sources

• U-100 syringe standard (100 units per mL): FDA insulin syringe labeling guidelines
• Tesamorelin vial sizes and reconstitution practice: Egrifta SV prescribing information (Theratechnologies)
• BAC water and lyophilized peptide reconstitution basics: USP general chapter on injections and implanted drug products
• peptidefox.com, peptidereconstitutecalculator.com, mypeptidematch.com, peptides.org: publicly accessible web tools, verified 2025