Math onlyThis is an independent calculator. It turns the numbers you type into a syringe reading and nothing more. Most peptides discussed online are not FDA-approved for any use, and this site never suggests an amount. Each peptide page states the regulatory status and the evidence, with sources.
How the peptide calculator works
Three numbers decide the answer: how much peptide is in the vial, how much liquid you added, and how much you need to measure. The calculator runs the same three lines of arithmetic you could do on paper.
Worked example. A 5 mg vial mixed with 2 mL holds 5 ÷ 2 = 2.5 mg/mL. An amount of 100 mcg is 0.1 mg, so it sits in 0.1 ÷ 2.5 = 0.04 mL. On a U-100 syringe that is 0.04 × 100 = 4 units. Each unit of this mix holds 25 mcg.
A U-100 insulin syringe is marked so that 100 units equal 1 mL.[2] If your syringe is marked U-40 or only in mL, the unit numbers on this site do not apply. The full code behind the calculator, with its tests, is on the formulas page.
mcg or mg: check before you type
Peptide amounts are often written in micrograms (mcg), while vials are labeled in milligrams (mg). One milligram is 1,000 micrograms, so 250 mcg is 0.25 mg. The calculator has a mg/mcg switch next to the amount. A slip between the two is a thousandfold error. The mg to mcg chart lists the common conversions.
Concentration quick reference
The concentration depends only on the vial and the diluent volume. These rows cover round combinations. "mcg per unit" tells you what one line on a U-100 syringe holds.
| Vial + diluent | mg/mL | mcg per unit | Units per 100 mcg |
|---|---|---|---|
| 2 mg + 1 mL | 2 | 20 | 5 |
| 2 mg + 2 mL | 1 | 10 | 10 |
| 2 mg + 3 mL | 0.667 | 6.67 | 15 |
| 5 mg + 1 mL | 5 | 50 | 2 |
| 5 mg + 2 mL | 2.5 | 25 | 4 |
| 5 mg + 3 mL | 1.667 | 16.67 | 6 |
| 10 mg + 1 mL | 10 | 100 | 1 |
| 10 mg + 2 mL | 5 | 50 | 2 |
| 10 mg + 3 mL | 3.333 | 33.33 | 3 |
Units for example amounts
The grid below is pure arithmetic for a 5 mg vial. The amounts are round numbers chosen to show the pattern; they are not doses for any peptide. For other vial sizes, see the units charts.
| Amount | 1 mL | 2 mL | 2.5 mL | 3 mL |
|---|---|---|---|---|
| 50 mcg | 1 | 2 | 2.5 | 3 |
| 100 mcg | 2 | 4 | 5 | 6 |
| 200 mcg | 4 | 8 | 10 | 12 |
| 250 mcg | 5 | 10 | 12.5 | 15 |
| 500 mcg | 10 | 20 | 25 | 30 |
| 1,000 mcg | 20 | 40 | 50 | 60 |
Look along any row: doubling the water doubles the units for the same amount. At 1 mL, 50 mcg is only 1 unit, which is below what most syringe markings can show reliably. That is why the diluent volume matters, and it is covered in the reconstitution guide.
Peptide molecular weight from a sequence
A peptide's molecular weight is the sum of its amino acid residues plus one molecule of water: BPC-157's 15 residues come to 1,419.56 g/mol. Paste any sequence in one-letter codes below to get the weight, the formula and the mg-to-nanomole conversion.
peptide_mw
sequence → formula, average and monoisotopic mass
Calculating…
Formula. MW = sum of residue masses + H2O. Average masses use IUPAC atomic weights; monoisotopic masses use NIST isotope masses.
How the molecular weight is calculated
Each amino acid in a chain has lost one water molecule to the bond on either side, so the calculator adds up the residue formulas and then adds one water back for the two free ends.
Atomic weights are the IUPAC abridged standard values,[4] and monoisotopic masses use NIST's isotope masses for 1H, 12C, 14N, 16O and 32S.[5] The code is checked against published formulas every time the site is built:
| Peptide | Calculated formula | Calculated MW | Published MW |
|---|---|---|---|
| BPC-157 | C62H98N16O22 | 1,419.56 | 1,419.5[6] |
| TB-500 (Ac-LKKTETQ) | C38H68N10O14 | 889.02 | 889[7] |
| MOTS-c | C101H152N28O22S2 | 2,174.62 | 2,174.6[8] |
| Sermorelin (C-terminal amide) | C149H246N44O42S | 3,357.93 | 3,357.9[9] |
| CJC-1295, no DAC (amide) | C152H252N44O42 | 3,367.95 | 3,367.95[10] |
| AOD-9604 (1 disulfide) | C78H123N23O23S2 | 1,815.1 | 1,815.1[11] |
Molecular weight is what turns micrograms into molecules. Some studies report amounts in nanomoles per kilogram; ipamorelin's intravenous study is one. Each peptide page shows micrograms and nanomoles side by side.
Peptide pages
Each page has the calculator set up for that peptide's units, its FDA status, and what published human studies show. A page lists doses only when they come from an FDA-approved label or a published human trial.
- BPC-157Not approved 15-amino-acid peptide. Human data: a few tiny, uncontrolled studies.
- TB-500Not approved A 7-amino-acid fragment of thymosin beta-4. No human trials of TB-500 itself.
- BPC-157 + TB-500 blendNot approved Two peptides in one vial: the arithmetic of a fixed ratio.
- TesamorelinFDA-approved Egrifta SV and Egrifta WR. Labeled doses, diluents and volumes.
- CJC-1295 / ipamorelinNot approved Two growth-hormone secretagogues, often sold together. Both rejected for compounding in 2024.
- SermorelinDiscontinued Once sold as Geref. Discontinued in 2008, not for safety reasons.
- GHK-CuNot approved Copper peptide. Studied on skin; injectable use has no published trials.
- MOTS-cNot approved 16-amino-acid mitochondrial peptide. No human trials of MOTS-c itself.
- PT-141 (bremelanotide)FDA-approved Vyleesi: a prefilled 1.75 mg autoinjector. No mixing needed.
- SS-31 (elamipretide)FDA-approved Forzinity, approved 2025 for Barth syndrome. Ready-to-use; no mixing.
- AOD-9604Not approved Growth hormone fragment. Obesity trials failed; committee voted 0–12.
- KPVNot approved Lys-Pro-Val tripeptide. No human data by any route.
- EpitalonNot approved AEDG tetrapeptide. FDA flags a theoretical cancer risk.
- SemaxNot approved ACTH-based heptapeptide. Intranasal studies only.
- SelankNot approved TP-7 heptapeptide. Never reviewed by the FDA committee.
- CagrilintideNot approved Amylin analogue; CagriSema under FDA review.
- MT2 (melanotan II)Not approved Melanotan II. Never approved; FDA cites melanoma reports.
- Thymosin alpha-1Approved in Italy Thymalfasin (Zadaxin). Not approved in the U.S.; 2025 sepsis trial negative.
- KisspeptinNot approved Reproductive-hormone signal. Kisspeptin-10 is on FDA Category 2.
- DSIP (emideltide)Not approved Delta sleep-inducing peptide. Small IV studies, 1981–1998.
- GHRP-6Not approved Growth hormone-releasing hexapeptide. On FDA 503B Category 2.
- HexarelinNot approved GHRP-6 plus one methyl group. Studied in the 1990s, never approved.
- LL-37Not approved Human cathelicidin. Topical wound trials; FDA cites tumor concerns.
Guides and reference
- Peptide status tableFDA approval, compounding and WADA status side by side
- Are peptides safe?Approved vs research-use peptides, per the FDA
- Are peptides legal?Approval, compounding and the 2026 HHS policy
- Are peptides banned in sports?Where each peptide sits on the WADA 2026 list
- Bac water for peptidesWhat the bacteriostatic water label says
- How to store peptidesFridge or room temperature, from the labels
- What are peptides?Definitions, sizes and the 40-amino-acid line
- HGH peptides comparedSermorelin vs tesamorelin vs ipamorelin and CJC-1295
- Is NAD a peptide?Why NAD+ is a coenzyme, and its FDA status
- Are peptides steroids?Chemistry, U.S. law and WADA, side by side
- What is a peptide bond?How amino acids join, with dipeptide and tripeptide pages
- Copper peptide serumWhat topical GHK-Cu studies show
- How to reconstitute peptidesThe steps, label instructions and open formulas
What this site will not do
This site does not suggest amounts, link to sellers or hide its math.
- Suggest amounts. You type the amount. The site does not recommend one, and it publishes no protocols, cycles or "stacks".
- Link to sellers. There are no shop links, discount codes or vendor reviews anywhere on the site.
- Hide the math. Every formula is printed next to the tool that uses it.
This matters because of how peptide calculators have been used. In August 2026 the FDA warned a seller of "research use only" peptides. The agency said that selling bacteriostatic water next to a "peptide guide" and a "peptide calculator" showed the products were meant for people.[1] This site sells nothing. It is an arithmetic and education tool, and the formulas are open so anyone can check them.
New to the subject? Start with what peptides are and keep the peptide glossary open for the terms. A peptide drug is a chain of up to 40 amino acids; longer chains are regulated as biological products in the U.S.[3]
Frequently asked questions
How do I calculate a peptide dose in units?
Divide the mg in the vial by the mL of liquid you added to get mg per mL. Divide the amount you need (in mg) by that concentration to get mL. Multiply mL by 100 for units on a U-100 syringe. The calculator above does all three steps.
How many units is 100 mcg?
It depends on the concentration. At 2.5 mg/mL (5 mg in 2 mL) it is 4 units. At 5 mg/mL (5 mg in 1 mL) it is 2 units. At 1 mg/mL (2 mg in 2 mL) it is 10 units.
How much water should I add to a peptide vial?
There is no single number. More water makes small amounts easier to measure but makes larger amounts take more of the syringe. The reconstitution guide shows the trade-off. For an approved medicine, follow its label; for example, the tesamorelin label specifies its own diluent and volume.
Is there a free peptide calculator app?
This page is a free peptide calculator that works in any phone or desktop browser, with nothing to install and no account. Your numbers stay in the browser; the copy-link button saves a result as a URL.
Does the calculator work for every peptide?
Yes. The arithmetic is the same for any powder dissolved in a known volume and measured on a U-100 syringe. The calculator cannot know whether a product actually contains what its label says.
Why does the calculator not suggest a dose?
Because most of these peptides are not approved medicines, and dosing is a medical decision. The site does math and education only. Peptide pages report doses only from approved labels or published human studies, with sources.
Sources
- Warning letter: Royal Peptides LLC
- 510(k) clearance K233794, Insulin Syringe ("U-100 means there are 100 units of insulin in every mL")
- Final rule: Definition of the term "biological product" (85 FR 10057)
- Abridged standard atomic weights 2024
- Atomic weights and isotopic compositions for all elements
- PubChem CID 9941957: BPC-157
- PubChem CID 62707662: TB-500 (Ac-LKKTETQ)
- PubChem CID 146675088: MOTS-c
- PubChem CID 16132413: sermorelin
- FDA briefing document: CJC-1295-related bulk drug substances
- PubChem CID 71300630: AOD-9604