Peptide Vendor Reviews: 100 US Vendors Independently Audited
Detailed editorial reviews of every US peptide source we have audited. Lab evidence, shipping policy, pricing, tenure, and transparency scored on a public formula and updated as new evidence comes in.
About This Review Program
Peptide Source Review is an independent editorial directory of US research-peptide vendors. Every vendor in the catalog is reviewed using the same published formula, with the underlying evidence linked from each vendor page. We do not accept payment for placement. Sponsorship and affiliate relationships are disclosed and never influence the scoring.
The catalog currently covers:
- 100 US peptide vendors, each with a full editorial review
- 2,401 product listings spanning 71 peptides
- 1,686 certificates read and checked (70% of carried listings); 1,436 products have a certificate whose key we confirmed at the issuing laboratory and credited under the lab rule (the figure on the verification page)
- 32 lab profiles covering the third-party labs that vendors in the directory name as their testers
Full methodology, including the scoring formula and gate rules, is published on How We Rate. Editorial principles, conflict-of-interest controls, and the editorial firewall around affiliate revenue are documented on Why Trust Us.
Top 20 Vendors by Score
This ranking is rebuilt from our current scores every time the site updates; each vendor page shows the date of its latest audit. Click through to see lab evidence, shipping policy details, pricing analysis, and the full editorial breakdown.
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Reviews by Peptide
Sometimes the best vendor for one peptide is not the best vendor for another. Each per-peptide page orders vendors by the lab-rule score of their certificate for that compound (out of 10), then by the vendor's published score, then alphabetically. Price per milligram is shown but does not change the order.
- BPC-157: Synthetic peptide fragment
- TB-500: Thymosin beta-4 fragment
- GHK-Cu: Copper tripeptide
- CJC-1295: Growth-hormone secretagogue
- Ipamorelin: Growth-hormone secretagogue
- Semax: ACTH-derived peptide
- Selank: Tuftsin analog
- Melanotan-2: Melanocortin agonist
- Sermorelin: Growth-hormone secretagogue
- Tesamorelin: Growth-hormone secretagogue
- Retatrutide: GLP-1 family (triagonist)
- Tirzepatide: GLP-1 family (dual agonist)
- Semaglutide: GLP-1 family
- NAD+: Coenzyme (dinucleotide)
- MOTS-c: Mitochondrial-derived peptide
- KPV: Alpha-MSH fragment
- Epitalon: Bioregulator tetrapeptide
- Thymalin: Thymic peptide preparation
How These Reviews Are Built
Each vendor review goes through the same five-step process:
- Site audit. We document the vendor's published shipping policy, refund policy, payment methods, contact details, business address, and any regulatory disclosures.
- COA collection. Every COA the vendor publishes for each peptide we track is collected, archived, and indexed.
- Lab verification. Each COA's named lab is checked against our verified lab catalog. Unnamed labs, self-issued documents, and unverifiable claims are flagged.
- Certificate reading. Where the lab is named, we read each certificate and record batch numbers, analyst signatures, purity percentages, tested dates, and other batch-specific metadata. This catches URL rot, stale COAs, and documents that look real but turn out to be marketing material rather than test reports.
- Scoring. The published formula combines lab credibility, shipping/refund integrity, pricing relative to market, operating history, and business transparency. The gate cap applies when third-party testing cannot be independently verified.
We aim to re-audit every vendor at least once a quarter; a store that is not taking orders keeps the scores from its last full audit, is checked daily and is re-audited when it reopens (rule F1), and a vendor that shows its catalogue only to signed-in customers is read through an account (rule F3). The methodology change log is published at Methodology Changelog.
What the Reviews Surface
Some of the things our audits have surfaced that buyers would not find without independent verification:
- Vendors publishing self-issued "COAs" from their own internal "research department" as if they were third-party reports.
- Vendors linking "Certificates of Manufacturing" (notarized marketing documents) in the COA slot, with no actual test results inside.
- Vendors whose COA URLs return 404 (file moved or deleted) months after publication.
- Vendors whose most recent published COA is 3-5 years old.
- Vendors whose site has gone offline entirely (domain not resolving).
- Vendors whose GLP-1 listings were no longer on their site after an FDA warning letter named those products.
- Vendors whose Freedom Diagnostics COAs test two or three vials and include an endotoxin result; our rubric credits the endotoxin result (+0.5), but the number of vials tested is not scored.
Each of these findings is documented on the relevant vendor page with a clear note and the underlying evidence linked.
Frequently Asked Questions
How recently were these reviews updated?
Our most recent audit was published on 2026-11-06. Specific vendor "last scored" dates are shown on each vendor profile page. Affiliate status plays no part in scoring or in when a vendor is re-audited.
Can I trust a vendor under the testing gate?
The testing gate means we could not independently verify the vendor's third-party testing. It records that testing could not be verified; it is not a finding of a quality or safety problem. Some gated vendors may work with a lab we have not been able to confirm. Read the specific reason on the vendor page and form your own judgment.
Do you accept paid reviews?
No. Vendors cannot pay for a review, pay to change a score, or pay for placement on the directory. We may have affiliate relationships with select vendors, disclosed on the Affiliate Disclosure page, but those relationships do not influence the scoring.
How can I submit a correction or new vendor?
Use the Submit page. Corrections are reviewed and published with attribution when appropriate. New vendor submissions go through a 1-2 week audit before appearing in the public ranking.