We Tested 9 Peptide Vendors. Only 3 Passed Our Purity Standards.

If you've spent any time researching peptide vendors, you know the landscape is a minefield. Every vendor claims "99%+ purity" and waves around certificates of analysis — but most of those CoAs are self-generated, untested by any independent lab, and in some cases, entirely fabricated.

We wanted to find out which vendors actually deliver what they promise. So over the past six months, we ordered research peptides from nine of the most-recommended US-based vendors and sent samples to Janoshik Analytical (Czech Republic) for independent HPLC purity testing — the gold standard for peptide verification.

The results were eye-opening. Some vendors delivered research-grade material with verified purity above 98%. Others fell dramatically short — including one popular vendor whose BPC-157 tested at just 74% purity with significant unidentified impurities.

How We Evaluated

Each vendor was scored across four dimensions: independently verified purity (weighted heaviest), shipping reliability and speed, pricing relative to verified quality, and customer service responsiveness. We also factored in community reputation from research forums and whether the vendor provides batch-specific CoAs from accredited labs.

Our Top 3 Verified Vendors

Full Comparison

Methodology

The research peptide market is growing rapidly, but quality remains wildly inconsistent. Our recommendation is simple: verify independently, don't trust self-generated CoAs, and prioritize vendors who welcome third-party scrutiny.

We'll continue updating this comparison as we test new batches and additional vendors. If you want to stay informed, grab the full report above — we send updates whenever new lab data comes in.