Methodology
This ranking uses two real, checkable factors: whether a vendor uses independent third-party COA (Certificate of Analysis) testing rather than in-house-only testing, and how many products in our tracked catalog that vendor carries — a proxy for how much of our research library you can shop through a single, verified vendor. Vendors using only in-house testing are excluded from the ranked list, regardless of catalog size.
The Ranking
1
American Peptides
30 products tracked · Third-party COA
The broadest catalog of any vendor we track, entirely covered by independent testing claims.
2
Amino Vault
26 products tracked · Third-party COA
Close behind in catalog breadth, also fully third-party tested across the compounds we track.
3
SwissChems
18 products tracked · Third-party COA
A strong middle-tier catalog with consistent independent testing claims across SARMs and peptides alike.
4
UK Sarms
17 products tracked · Third-party COA
The top UK-based option on this list by catalog size, also third-party tested.
5
Chemyo
13 products tracked · Third-party COA
A US-based SARMs specialist — every listing is backed by independent FTIR/HPLC testing for identity, purity and concentration. Catalog is SARMs-only, with no peptide or GLP-1 coverage.
No Vendor Pays for a Better Spot
This ranking, like the ratings on our Reviews page, is computed from real, disclosed criteria — testing methodology and catalog breadth — not payment. MuscleChem, which uses in-house rather than third-party testing, is excluded from this specific ranked list for that reason alone, not because of price or any other factor; it remains a fully listed vendor across relevant product pages with that testing distinction clearly flagged.
FAQ
What does "third-party COA" mean?
It means the vendor provides a Certificate of Analysis from an independent lab, not just their own in-house testing — an important distinction when evaluating purity claims.
Why isn't MuscleChem on this list?
MuscleChem uses in-house testing rather than third-party verification, which is the specific, disclosed exclusion criterion for this ranking. It's still a listed vendor on this site with that distinction clearly flagged on every relevant product page.
Does a bigger catalog mean better quality?
Not by itself — catalog size here is a measure of how much of our tracked research library you can access through one already-verified vendor, not a quality score on its own.
References
Live vendor catalog and testing-status data as tracked across Compound X product comparison tables, August 2026.
