Research Tools
Molarity Calculator
Convert between molar concentration (nM/μM/mM/M) and mass concentration (mg/mL/μg/mL) for any peptide or small molecule. Select a compound for automatic MW lookup or enter a custom molecular weight.
1. Select Compound or Enter MW
2. Conversion Mode
3. Enter Concentration
⚠ Select a compound or enter a custom MW above to see results.
Rodent Dose → Molar Amount
Useful for in vitro planning: given an in vivo dose, calculate the absolute molar amount injected.
BPC-157 typical: 10 μg/kg · Ipamorelin: 100 mcg/kg
Compound MW Reference Table
| Compound | Category | MW (g/mol) | |
|---|---|---|---|
| BPC-157 | Recovery | 1,419.55 | |
| TB-500 (Thymosin Beta-4 fragment) | Recovery | 4,963.5 | |
| GHK-Cu | Recovery | 403.95 | |
| Ipamorelin | GH Axis | 711.85 | |
| CJC-1295 No DAC | GH Axis | 3,367.97 | |
| CJC-1295 (DAC) | GH Axis | 3,647.28 | |
| Sermorelin | GH Axis | 3,357.93 | |
| MK-677 (Ibutamoren) | GH Axis | 624.77 | |
| Tesamorelin | GH Axis | 5,135.79 | |
| Hexarelin | GH Axis | 887.05 | |
| Semaglutide | Metabolic | 4,113.58 | |
| Tirzepatide | Metabolic | 4,813.48 | |
| Retatrutide | Metabolic | 4,762.49 | |
| AOD-9604 | Metabolic | 1,815.11 | |
| NAD+ | Longevity | 663.43 | |
| Epitalon | Longevity | 390.35 | |
| SS-31 (Elamipretide) | Longevity | 640.82 | |
| MOTS-c | Longevity | 2,174.5 | |
| Follistatin 344 | Longevity | 37,340 | |
| Selank | Nootropics | 751.86 | |
| Semax | Nootropics | 813.96 | |
| DSIP | Nootropics | 848.83 | |
| Thymosin Alpha-1 | Immunology | 3,108.47 | |
| KPV | Immunology | 341.38 | |
| LL-37 | Immunology | 4,493.35 | |
| PT-141 (Bremelanotide) | Reproductive | 1,025.2 | |
| Melanotan II | Reproductive | 1,024.2 | |
| Kisspeptin | Reproductive | 1,302.51 | |
| Oxytocin | Reproductive | 1,007.19 | |
| Snap-8 | Cosmetic | 1,076.22 |
Why Molar Concentration Matters
Cell culture & in vitro assays
Receptor binding EC₅₀ and Ki values are reported in molar units (nM/μM). When preparing peptide solutions for cell culture, you must convert your stock mg/mL concentration to nM to know whether you're working near, at, or above the EC₅₀. For example, semaglutide's GLP-1R EC₅₀ ≈ 0.06 nM — a 1 mg/mL stock is ~243 μM, or ~4 million-fold above the EC₅₀.
Comparing compounds of different MW
A “10 μg/mL” solution of BPC-157 (MW 1,420 g/mol) contains 7.04 μM, while 10 μg/mL of SS-31 (MW 641 g/mol) contains 15.6 μM — more than twice the molar concentration. Equimolar dosing requires MW-adjusted preparation, not equivalent mg/kg dosing.
Reporting in publications
Most peer-reviewed journals require molar units for dose-response curves and mechanistic studies. Converting your working concentrations to nM/μM before submission is required — this tool generates the exact values for your methods section.