Lot-specific analytical documentation, published data, and a documentation-first quality standard.
Phase 1 Peptides is a U.S.-based supplier of research-grade peptides built for scientists, by people who understand what researchers actually need: verified purity, fast fulfillment, and straightforward pricing. We exist to remove the friction between researchers and the materials they depend on.
We carry over 40 research compounds across five categories, including Metabolic & Endocrine, Musculoskeletal & Growth, Cellular & Longevity, Neuropeptides & Immunology, and Reproductive & Hormonal, along with reconstitution supplies. Every product is intended exclusively for laboratory research and in vitro studies.
We are not a compounding pharmacy, an outsourcing facility, or a clinical supplier. That singular focus is what allows us to do one thing exceptionally well.
The research peptide space has a trust problem. Too many suppliers cut corners on testing, obscure their sourcing, or make it difficult to verify what you're actually buying. We built Phase 1 to be the opposite of that.
We don't sell anything that hasn't passed. There are no exceptions.
Each lot is independently analyzed by third-party analytical laboratories. Materials that do not meet our purity standard are refused, and lot-specific analytical records are published where available.
Select compounds also include additional analyses such as net peptide content where applicable. Lot-specific analytical records are published as Certificates of Analysis where available — see the Lab Tests page.
Independent third-party analytical testing, with lot-specific COAs published where available.
Every COA is published unedited with batch numbers, test dates, and complete methodology.
Standard, Express, and Overnight options. Free shipping on orders over $200.
No hidden fees, no inflated markups. Phase 1 Welcome Savings apply automatically at checkout.
Lost, stolen, or damaged shipments are covered at no extra cost. Handled directly by our team.
Real humans, not bots. Reach us at support@phase1-peptides.com and most inquiries resolve within hours.
40+ independently tested peptides. Lot-specific analytical documentation where available.
Shop Peptides