All seven vendors we compared in September list Semax, and Peptide Plugs documents its testing best: its product page gives a lot, a Freedom Diagnostics accession code, purity and measured content. PSPeptides and Alpha Pro Peptides also post Semax certificates with a named lab, and NextGenPeps names Janoshik with an endotoxin result. No vendor has independent Finnrick data for Semax.
Notice: Research peptides are sold for in-vitro laboratory research only. They are not FDA-approved, not for human or animal consumption, and this page is not medical advice.
Our criterion: a Semax-specific COA with a named lab and lot number beats a generic "third-party tested" claim. We don't test products; we check what each vendor publishes.
Regulatory status of Semax
- FDA: Semax isn't an approved drug. FDA's Category 2 compounding page (content current as of April 22, 2026) lists "semax (heptapeptide)" among nominations "withdrawn by the nominators," with FDA's note that it "may pose risk for immunogenicity for certain routes of administration."
- July 2026 advisory vote: FDA's Pharmacy Compounding Advisory Committee voted 8 yes, 5 no, 1 abstaining to recommend Semax for the 503A bulks list (RAPS; Restore Health Consulting). It's non-binding and concerns licensed pharmacy compounding, not research-use sales. As of September 26, 2026, we found no FDA decision.
- WADA: the 2026 Prohibited List doesn't name Semax (2026 list text). Its S0 section prohibits substances "with no current approval by any governmental regulatory health authority for human therapeutic use."
- DEA: not on DEA's controlled substances list dated August 27, 2026.
More: are peptides legal? and FDA peptide regulation in 2026.
Semax by vendor
Single-vial prices shown on September 26, 2026, including any displayed sale price. $/mg is price divided by labeled mg. Vendors appear in our editors' order, which isn't sorted by score.
| Vendor | Stocks it | Vial size(s) | Price | $/mg | Semax COA / lab | Review |
|---|
| American Peptides | Yes | 10 mg | $65 | $6.50 | Lot SEMX10-0803; lab not shown | Review |
| NextGenPeps | Yes | 10 mg | $42 | $4.20 | Janoshik, June 19, 2026, 98.848%; no lot shown | Review |
| PSPeptides | Yes | 11 mg | $42.99 | $3.91 | North American Diagnostics, batch PSP-06112026SX, June 11, 2026 | Review |
| Ascension Peptides | Yes | 10 mg | $50.00 | $5.00 | Kovera Labs, batch 30-05260628, June 23, 2026 | Review |
| Peptide Plugs | Yes | 10 mg | $40 | $4.00 | Freedom Diagnostics, lot 148-03-DK, accession code | Review |
| Swiss Chems | Listed, stock not confirmed | 30 mg | $73.95 | $2.47 | No Semax report found | Review |
| Alpha Pro Peptides | Yes (stock not shown) | 10 mg | $34.99 | $3.50 | Freedom Diagnostics, Aug 20, 2026 | Review |
Notes on the table:
- American Peptides: the Semax page lists one 10 mg size. Its COA page shows lot SEMX10-0803 plus two superseded lots, with no lab or purity shown. It also sells Semax sprays and blends, which this page doesn't cover.
- NextGenPeps: the product page showed $42, down from $52. Its COA library lists a June 2026 Janoshik report with endotoxin under 1 EU per vial, and a July 2025 BioRegen report.
- PSPeptides: the product page links heavy metals and endotoxin reports too. The June certificate reports 99.93% purity and 10.90 mg measured for an 11 mg vial, by HPLC with mass spectrometry.
- Ascension Peptides: the product page lists Kovera Labs (June 2026) and MZ Biolabs (February 2026) batches, with no purity shown on the page (checked September 26, 2026). Regular price is $59.99.
- Peptide Plugs: the product page reports 99.79% purity and 12.28 mg measured, 22.8% over the 10 mg label. The $24 advertised price is for 10 or more vials. It also sells a Selank + Semax 20 mg blend.
- Swiss Chems: the product page showed an out-of-stock notice for the selected option. We found no Semax report on its test results page.
- Alpha Pro Peptides: the August certificate is from Freedom Diagnostics: 99.34% purity by LC-MS and 12.99 mg measured. The PDF prints lot "0724," while the testing page lists it under a different ID. An older May row for Semax lists a second net content labeled "GLP SM," so read that entry carefully.
- Licensed Peptides (added to our list September 28, 2026; not in the table): it sells Semax only as a nasal spray, which was sold out (shop, checked September 28, 2026), so it isn't comparable with the vials above. Review
What is Semax?
Semax is a synthetic peptide described in PubMed-indexed papers as "an analog of ACTH(4-10)", a fragment of adrenocorticotropic hormone. Published studies are mostly in rodents, such as work on BDNF expression in the rat hippocampus. That research doesn't establish effects in people.
How to check a Semax COA
- Match the lot on the certificate to your vial label, and check that the PDF's lot matches the vendor's listing.
- Read the lab name on each PDF, then look the lab up.
- Check identity by mass spectrometry, not just HPLC purity.
- Compare measured content to the label. Measured Semax ranged from 10.90 mg (11 mg label) to 12.99 mg (10 mg label) across these certificates, which changes concentration math.
See how to read a peptide COA, the COA checklist and the reconstitution calculator.
Independent test data
None of the seven vendors we compared had independent Finnrick results for Semax on September 26, 2026. Licensed Peptides, which we added on September 28, 2026, has no Finnrick profile. Finnrick lists ten tests for Swiss Chems, covering BPC-157, ipamorelin and CJC-1295 only, and the other six vendors we compared have no Finnrick tests. Every certificate above was commissioned by the vendor, which chooses the sample it sends. More on community testing: what is Finnrick?
Vendor links
In our editors' order. Each review covers the vendor's policies, red flags and full testing record.
Bottom line
For Semax, Peptide Plugs has the most checkable documentation. PSPeptides and Alpha Pro Peptides name labs on recent certificates, though PSPeptides' blog publishes human dosing guides, which we count against it. NextGenPeps names Janoshik and reports endotoxin but shows no lot. Ascension names labs without showing purity on the page, American Peptides doesn't show the lab, and Swiss Chems posts no Semax report. For the full comparison, see best peptide vendors in the USA and third-party tested peptides.
Rank 1
