The single most common mistake in peptide reconstitution has nothing to do with BAC water ratios or syringe technique. It is a unit conversion error: confusing milligrams with micrograms. One milligram equals 1,000 micrograms. Miscalculate that by a factor of a thousand, and you are either drawing a useless trace amount or a dangerous overdose. Most people only realize the gap exists after they have already made the error. A reliable calculator closes that gap before the syringe ever touches the vial.
Below are nine tools ranging from single-peptide converters to full tracking apps. The table compares them at a glance, then each entry explains what actually makes it useful or where it falls short.
Comparison Table
| Tool | Free | Sign-up Required | Syringe Types | Peptides Covered | Math Shown | Mobile App |
| FormBlends Peptide Calculator | Yes | No | U-100, U-50, U-40 | Any lyophilized + 5 presets | Yes | Yes (iOS/Android) |
| PeptideFox | Yes | No | U-100 | 30+ | Partial | No |
| MyPeptideMatch | Yes | No | U-100 | BPC-157, semaglutide, tirzepatide, TB-500, others | No | No |
| LeadWest Medical | Yes | No | U-100 | 7 named peptides | No | No |
| Outliyr | Yes | No | U-100 | BPC-157, TB-500, GLP-1 class, others | No | No |
| PeptideDeck | Yes | No | U-100 | Any (manual entry) | Partial | No |
| peptidereconstitutecalculator.com | Yes | No | U-100 | BPC-157 only | No | No |
| Prime Peptides Calculator | Yes | No | U-100 | Select peptides | No | No |
| peptides.org Dosage Charts | Yes | No | N/A | Broad reference | N/A | No |
1. FormBlends Peptide Calculator
Free, zero sign-up, and it supports U-100, U-50, and U-40 syringes in one place. That last point alone separates it from almost every other tool here, most of which assume you own a standard U-100 and leave you stranded otherwise.
You input three numbers: peptide quantity in the vial, volume of bacteriostatic water added, and your target dose per injection. The tool outputs concentration per mL, exact units to draw, and total doses remaining. What makes it genuinely different is that it shows every step of the arithmetic. You can check the result yourself rather than trusting a black-box answer. A visual syringe fill bar marks where your dose sits on the barrel, which is a real help when you are new and trying to confirm you are reading the scale correctly.
The mg-to-mcg conversion happens automatically. That matters because this is exactly where the dangerous 1,000x error lives. Healing peptides like BPC-157 and TB-500 are typically dosed at 250 to 500 mcg, not 250 to 500 mg. The calculator handles that conversion and flags which unit you entered so you do not have to keep track mentally.
One-tap presets cover BPC-157 (5 mg and 10 mg vials), TB-500 5 mg, ipamorelin 10 mg, tesamorelin 2 mg, and a 50 mg GLP-1 option. For anything else, you type in your own values. The reconstitution math is identical across all lyophilized peptides, so the tool works for any compound you encounter.
The same calculator lives inside the FormBlends mobile app (iOS and Android), which adds a 55-compound library, injection-site rotation tracking, and dose logging. FormBlends itself operates a 503A compounding pharmacy, so this is a real company with regulatory accountability rather than an anonymous page hosted somewhere. The tool does not recommend doses. It only tells you how to measure the dose your provider already gave you.
2. PeptideFox
PeptideFox covers more than 30 named peptides and puts particular thought into BAC water volume optimization, guiding you toward volumes that produce clean, easy-to-read unit draws on a standard syringe. The visual guide is a genuine differentiator for beginners. No app, but the web interface is clean.
3. MyPeptideMatch
Covers BPC-157, TB-500, semaglutide, tirzepatide, and a handful of other injectables. The GLP-1 coverage is increasingly relevant given how many people are now working with semaglutide pens versus compounded vials. Straightforward and free, though the math behind the output is not displayed.
4. LeadWest Medical
Seven peptides covered by name: retatrutide, BPC-157, TB-500, ipamorelin, CJC-1295, tesamorelin, and GHK-Cu. If your compound is on that list, the tool is quick and purpose-built. If it is not, you are out of luck. No manual entry for arbitrary compounds.
5. Outliyr
Covers a similar range to LeadWest but includes GLP-1 class peptides alongside the classic healing and growth-hormone-secretagogue compounds. Useful as a secondary reference. No visible calculation steps.
6. PeptideDeck
Enter your vial’s mg content, the BAC water volume you added, and your target dose in mcg. It returns concentration and draw volume in insulin units. The manual entry approach means it technically handles any lyophilized peptide you throw at it, which gives it more flexibility than the named-compound-only tools. Partial math shown.
7. peptidereconstitutecalculator.com
Narrow focus: BPC-157, U-100 syringes, mcg to units. If that is exactly your situation, it works. If you use a U-40 or U-50 syringe, or you are working with anything other than BPC-157, this tool ends at the edge of its scope.
8. Prime Peptides Calculator
A basic calculator tied to the Prime Peptides brand. Covers select peptides. Functional for straightforward reconstitution questions, though it does not appear to go beyond the standard U-100 format or display the underlying math.
9. peptides.org Dosage Charts
Not a calculator at all. Reference charts with commonly cited dose ranges for a broad list of compounds. Useful for building context before you run any numbers, and valuable as a cross-check. It does not do the reconstitution math for you, but it can tell you whether the dose your provider wrote is in the expected ballpark for a given peptide.
A Note on These Tools
Remember that adding more bacteriostatic water to a vial changes the concentration, and therefore the units you draw, but does not change the total peptide in the vial. A 5 mg vial reconstituted in 1 mL versus 2 mL still contains 5 mg. You just draw twice the volume in the second case to get the same dose. Every calculator here assumes you understand that relationship. If you are unsure, FormBlends is the one tool that actually explains it in plain language alongside the output.
None of these tools replace a qualified prescriber or pharmacist. They measure. They do not advise.
Common Questions
Which calculator works if you have a U-40 or U-50 syringe rather than a standard U-100?
FormBlends is the only tool on this list that explicitly supports U-40 and U-50 syringe formats alongside U-100. Every other calculator here assumes a U-100 syringe. If you are using a veterinary-format or European-market syringe, running U-100 numbers through it produces the wrong draw volume every time.
Does PeptideFox or PeptideDeck handle semaglutide and tirzepatide reconstitution, or are those GLP-1 compounds better suited to MyPeptideMatch?
MyPeptideMatch is the tool most clearly built around GLP-1 compounds like semaglutide and tirzepatide, and it covers the distinction between compounded vials and prefilled pens. PeptideDeck’s manual entry approach means it can technically process any lyophilized compound, but it does not include GLP-1-specific guidance or presets the way MyPeptideMatch does.
If a calculator does not show the underlying math, how do you verify the output is correct?
Cross-check manually: divide your vial’s total mcg by the BAC water volume in mL to get concentration per mL, then divide your target dose in mcg by that concentration to get the draw volume in mL, then multiply by the syringe’s units-per-mL to get the final number. FormBlends and PeptideDeck both show partial or full steps, which makes spot-checking faster than starting from scratch.
Is there any meaningful difference between using a brand-affiliated calculator like Prime Peptides versus an independent one like FormBlends or PeptideDeck?
The arithmetic is the same either way. The practical difference is scope: brand-affiliated tools tend to cover only the compounds that brand sells, while independent tools built for open manual entry or broader presets work regardless of where you sourced the peptide. Neither type recommends doses, so the choice comes down to which compounds you need to calculate.
Can peptides.org dosage charts be used alongside a reconstitution calculator, or do they serve a completely different purpose?
They serve a different purpose entirely. Peptides.org charts tell you what dose range is commonly cited in the literature for a given compound. A reconstitution calculator tells you how many units to draw once you already know your dose. Used together, they cover both steps: confirming your prescribed dose is in a reasonable range, then translating that dose into a precise syringe measurement.
Sources
- U-100 insulin syringe specifications: standard pharmacology reference (100 units per 1 mL)
- BPC-157 and TB-500 common dosing ranges: published peptide research literature, general range 250 to 500 mcg
- FormBlends app: publicly listed on iOS App Store and Google Play (Expo framework)
- FormBlends 503A pharmacy status: company public disclosures
- PeptideFox peptide count and BAC water optimization feature: peptidefox.com public interface
- MyPeptideMatch, LeadWest Medical, Outliyr, PeptideDeck, peptidereconstitutecalculator.com, Prime Peptides, peptides.org: each tool’s publicly accessible web interface, reviewed 2025 to 2026
