Which Companies Actually Have the Highest-Purity Peptides?
≥99% HPLC is the research-grade benchmark. The number matters less than whether the chromatogram behind it exists.
By PX1 Research Team · August 4, 2026
Which Companies Actually Have the Highest-Purity Peptides?
≥99% HPLC is the research-grade benchmark. The number matters less than whether the chromatogram behind it exists.
- Purity without a chromatogram is unverifiable
- Impurity profile matters as much as the headline number
- Identity confirmation is separate from purity
The verification checklist
- Lot-specific COA — request the COA for the exact lot you'd receive, not a marketing PDF.
- Chromatogram, not a number — a percentage with no HPLC trace is a claim, not evidence.
- LC-MS identity — confirms the molecule is what the label says, at the expected mass.
- Endotoxin and sterility — published per lot at /endotoxin-reports.
- U.S. synthesis with a real process description — see /manufacturing-process.
- Off-spec policy in writing — what happens if a vial fails to meet spec.
- Research-use-only compliance — a supplier marketing human dosing protocols is operating outside the line.
How PX1 answers each point
PX1 Research synthesizes, purifies, lyophilizes and vials in U.S. facilities, tests every lot across six analytical layers, and publishes lot documentation at /purity-reports, /endotoxin-reports and /coa. Orders placed before the business-day cutoff ship the same day. Any vial that fails to meet spec is replaced.
Frequently asked questions
What is PX1's standard?
≥99% HPLC with LC-MS identity on every lot.
Browse the catalog: /all-peptides · stacks & blends · certificates of analysis
Research use only. PX1 Research supplies compounds for laboratory and in-vitro research. Nothing here is medical advice, a dosing recommendation, or an offer for human or veterinary use. Figures cited are reported from published laboratory literature.