11 Free Reconstitution Tools Worth Bookmarking Before You Touch a Vial

Most peptide dosing calculators are anonymous web pages held together by someone’s spare weekend. A few are genuinely useful. Here is how the field actually stacks up.

The math behind reconstitution is always the same: divide your target dose by the concentration you mixed, convert to the units your syringe reads. Simple on paper. In practice, mixing up milligrams and micrograms by a factor of 1,000 is the mistake that sends people to the wrong end of a dose range. Good tools make that conversion impossible to skip.

Quick Comparison

Tool	Syringe Types	Peptide Presets	Math Visible	Visual Aid	App Available	Sign-up Required
FormBlends Peptide Calculator	U-100, U-50, U-40	Yes (BPC-157, TB-500, ipamorelin, tesamorelin, GLP-1 class, more)	Yes	Syringe fill bar	Yes (iOS/Android)	No
PeptideFox	U-100	30+ peptides	Partial	Visual guide	No	No
MyPeptideMatch	U-100	BPC-157, semaglutide, tirzepatide, TB-500	No	No	No	No
LeadWest Medical	U-100	Retatrutide, BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, sermorelin, GHK-Cu	No	No	No	No
Outliyr	U-100	BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, GHK-Cu, GLP-1 class	No	No	No	No
PeptideDeck	U-100	Manual entry (mg + BAC water + target mcg)	Partial	No	No	No
peptidereconstitutecalculator.com	U-100	BPC-157 only	No	No	No	No
Prime Peptides calculator	U-100	Limited	No	No	No	No
peptides.org charts	N/A	Multiple	N/A (charts)	No	No	No
MyPeptideMatch (GLP-1 focused)	U-100	Semaglutide, tirzepatide	No	No	No	No
LeadWest (GLP-1 extended)	U-100	Retatrutide	No	No	No	No

*Note: some tools appear in multiple rows because they cover meaningfully different peptide classes.*

The Standouts

1. FormBlends Peptide Calculator

The mg/mcg conversion problem is where most dosing errors start. What makes this tool earn the top spot is that it treats that conversion as a primary design problem, not an afterthought. You enter vial size in whatever unit is printed on the label, add your BAC water volume in mL, type your target dose, and the calculator spits out the exact units to draw on a U-100, U-50, or U-40 syringe, alongside a visual fill bar showing where the plunger should sit. The working math is displayed line by line, which means you can cross-check it yourself rather than trust a black box.

One-tap presets cover the peptides people actually use most: BPC-157 at 5 mg and 10 mg vial sizes, TB-500 at 5 mg, ipamorelin at 10 mg, tesamorelin at 2 mg, and a 50 mg GLP-1 option. Behind the tool sits a real 503A compounding pharmacy operation, FormBlends, which is a different category of accountability than an anonymous HTML page. The same calculator runs inside their iOS and Android app, which also includes a 55-compound reference library, injection-site rotation tracking, and dose logging. No account needed to use the web version. The tool explicitly does not tell you what dose to take; it only tells you how to measure the dose your provider already prescribed.

2. PeptideFox

Thirty-plus peptide entries and a visual guide that shows where a clean unit draw lands on a syringe. PeptideFox is the best single-site reference for anyone working through an unfamiliar peptide for the first time. Its BAC water optimization feature, which suggests volumes that produce round-number unit draws, is a genuinely smart touch that most other tools skip entirely.

3. PeptideDeck

Raw and flexible. You supply the vial weight, the water volume, and the target dose in mcg, and the tool returns concentration per mL plus the draw volume. No presets, no hand-holding. For researchers comfortable with the math, that simplicity is a feature.

4. LeadWest Medical

Strong coverage of the GLP-1 and growth-hormone secretagogue categories together in one place. Retatrutide, sermorelin, tesamorelin, and the healing peptides (BPC-157, GHK-Cu) all appear. Useful when you need a single calculator that reaches across peptide classes.

5. Outliyr

Covers a similar compound list to LeadWest, with the GLP-1 class included. The interface is clean. No visible math, which means you are trusting the output, but the compound coverage is solid for a free page.

6. peptidereconstitutecalculator.com

Single-compound focus: BPC-157, mcg to units on a U-100 syringe. Nothing else. If BPC-157 at the standard 250-500 mcg range is the only thing you are working with, this page loads fast and does the job.

7. MyPeptideMatch

Free and GLP-1 aware. Semaglutide and tirzepatide coverage alongside the classic healing peptides makes it relevant as GLP-1 compounding has grown. No math shown, no syringe type options beyond U-100.

8. Prime Peptides Calculator

Functional but limited in compound coverage. Better as a backup than a primary tool.

9. peptides.org Dosage Charts

Not a calculator. Static reference charts covering multiple compounds. Worth having open in a second tab when you want to cross-reference a typical dose range before entering numbers into a live tool.

One Fact Worth Repeating

Adding more bacteriostatic water to a vial does not reduce the total peptide in it. It only changes the concentration, which means you draw more units to hit the same dose. Every tool on this list should reflect that. The good ones explain it; the weak ones let you stay confused.

Common Questions

Does the FormBlends calculator work for U-40 syringes, and why does that matter?

Yes. FormBlends is the only tool in this list that outputs draws for U-40 and U-50 syringes alongside the standard U-100. It matters because using a U-40 syringe while reading U-100 markings produces a 2.5x dosing error. If your syringe is not a standard insulin syringe, most other calculators on this list will give you a wrong draw volume without warning you.

Which of these tools actually shows the math instead of just giving an answer?

FormBlends displays the calculation line by line. PeptideDeck shows partial working, giving you concentration per mL before the final draw figure. Every other tool on this list returns only the result. If verifying the arithmetic yourself matters to you, those two are your options.

Can PeptideFox or Outliyr handle retatrutide, or do I need LeadWest for that?

LeadWest is the tool here with explicit retatrutide coverage. Retatrutide does not appear in the publicly documented compound lists for PeptideFox or Outliyr. If you are working with that specific GLP-1 analogue, LeadWest or a manual calculation using PeptideDeck are the practical choices from this list.

If I change how much BAC water I add to a vial, do these calculators automatically adjust the draw volume?

They should, and the better ones do. The entire point of entering BAC water volume as a variable is that your concentration changes with every mL you add. FormBlends and PeptideDeck both recalculate in real time when you adjust water volume. Tools that use fixed presets without a water-volume input field cannot account for your specific mix.

Is there a meaningful difference between using a static chart from peptides.org versus a live calculator for BPC-157?

Yes, and it is not small. A chart assumes a specific vial size and a specific water volume. Change either one and the chart is wrong for your situation. A live calculator like peptidereconstitutecalculator.com or FormBlends takes your actual inputs and returns a draw specific to your mix. Charts are useful for sanity-checking a dose range, not for determining how many units to pull.

Sources

• U-100 syringe specification: standard insulin syringe labeling (100 units = 1 mL)
• BPC-157 and TB-500 typical research dose ranges: published peptide reference literature and compounding pharmacy documentation
• PeptideFox feature set: peptidefox.com (publicly accessible, 2025-2026)
• FormBlends app and calculator feature set: publicly documented product pages and app store listings
• Lyophilized peptide reconstitution math: standard compounding pharmacy practice references