The Global Directory of Peptide Suppliers

Peptides.SO is the global peptide supplier marketplace. We help researchers compare prices, read verified reviews, and find trusted suppliers for research peptides — all in one place.

We aggregate pricing data from verified suppliers and display it side by side. You can filter by peptide name, category, price range, purity, and stock status to find the best deal for your research needs.

Yes. Suppliers go through a verification process that includes reviewing certificates of analysis (COAs), third-party testing documentation, and ongoing customer feedback monitoring. Verified suppliers display a trust badge on their profile.

Peptides.SO is completely free for researchers and buyers. Compare prices, read reviews, set price alerts, and use our research tools at no cost. Suppliers pay a small commission on referred sales.

We offer free tools including a Reconstitution Calculator, Cost-per-mg Calculator, Half-Life Tracker, and Research Routine Planner — all designed to help researchers plan and optimize their peptide experiments.

Create a free account, then navigate to the supplier or peptide page you want to review. Click "Write a Review" and share your experience. Reviews are verified and moderated to ensure authenticity.

A Certificate of Analysis (COA) is a quality document from a peptide manufacturer or third-party lab confirming purity, identity, and safety testing results for a specific lot. A complete COA for research peptides includes HPLC purity percentage, mass spectrometry identity confirmation, and ideally endotoxin or sterility data. Always request a lot-specific COA before purchasing.

Trustworthy research peptide suppliers consistently provide lot-specific COAs with HPLC purity data (98%+), mass spectrometry confirmation of molecular weight, and ideally third-party lab verification. On Peptides.SO, check each supplier's Testing Scorecard and verified customer reviews. Suppliers with completed scorecards and consistent positive reviews are generally the most reliable.