Peptide lab tests & purity database

A COA is a single-batch laboratory document that reports the analytical purity of a specific lot of a research peptide. The trust-grade version comes from an independent third-party lab and includes the lot number, the analytical method (typically HPLC), the percentage purity, and the test date. Marketing pages that state '≥99% purity' without a per-batch document are a vendor specification, not a COA.

HPLC (high-performance liquid chromatography) is the standard analytical method for determining the purity of a synthetic peptide. The reported purity percentage is the area-under-the-curve of the target peptide peak relative to all other peaks. Peptides synthesised by solid-phase methods are not 100% pure even at the best labs; 99%+ is considered research-grade, and meaningful sub-99% drops usually indicate truncations, racemisation, or failed couplings.

In the records covered on this page, Ascension Peptides publishes the most consistent per-lot HPLC purity, with most batches clearing 99.5% on third-party reports. Sports Technology Labs publishes a comparable per-lot library with a wider variance across compounds. Sort the table by Purity (highest first) to see the ranked view across all 5 vendors.

No. '≥99% HPLC' on a product page is a marketing specification, a claim about what the vendor's process targets. A per-lot certificate of analysis is a document tied to the specific batch you receive, with a lot number you can match against the vial. We tag every record on this page with one of two badges: 'Per-lot COA' for vendors who publish per-batch documents, and 'Vendor spec' for vendors who publish only the marketing claim.

Most analytical chemistry courses treat 95% as the minimum threshold for a usable research-grade peptide; 98%+ is typical for well-known compounds, and 99%+ is the de-facto standard for the most-shipped catalog (BPC-157, TB-500, GLP-1 analogues, growth-hormone-releasing peptides). Lower purity does not necessarily indicate contamination but does indicate higher concentrations of related impurities, which can affect downstream research applications.

Peptide purity tracks with three things: synthesis difficulty (longer sequences are harder), the vendor's QC budget, and storage stability before testing. Smaller research compounds like DSIP, Epitalon, and PEG-MGF often test 90–98% even at reputable vendors because their solid-phase synthesis introduces predictable side products. Sub-90% on a popular compound like BPC-157 or Tirzepatide is a red flag.

Records are refreshed when partner vendors publish new lots or when we add a new vendor. The most recent test date currently in the database is 2026-03-20. We do not run the lab work; the linked COA on each row is the source of truth, and visitors should verify the document against the lot they receive.