Peptide Sciences Alternatives: Research Vendors Still Trading in 2026
By Russel Martin · Updated · Editorial policyContains affiliate links. We may earn a commission on purchases. More
Peptide Sciences is reported to have shut down in March 2026, and US searches for the brand fell from about 135,000 a month in January to about 22,000 in September. If you used it for research supply, these are the vendors we have checked that are still trading, with the facts that matter for a switch.
| Vendor | Status | Ships from | Lab reports | Refunds | Trustpilot |
|---|---|---|---|---|---|
 PSPeptides | Open | USA | Per lot; lab: N.A. Diagnostics | No returns; defects in 3 days; refund + test cost if purity < 80% | 4.6(268) |
 American Peptides | Open | USA (LA) | Per lot; lab: Bioviridian | Final once shipped; damage within 72 h | 4.1(69) |
 Ascension Peptides | Open | USA | Lot numbers not confirmed; lab not named | All sales final | — |
 Biotech Peptides | Open | — | Lot numbers not confirmed; lab not named | "30-day refund" but no returns | — |
 Core Peptides | Open | USA | Per lot; lab: Vanguard Laboratory | Refund request within 30 days of order | — |
| Limitless Life Nootropics | Open | — | Per product (no lot numbers seen); lab not named | Unopened items within 10 days | 3.3(164) |
 Palmetto Peptides | Open | USA | Per lot; lab not named | All sales final | — |
 Peptide Partners | Open | — | Lot numbers not confirmed; lab not named | Refund only before shipping | — |
 Pure Health Peptides | Open (domain redirects) | USA (CA) | Lot numbers not confirmed; lab not named | No general refund policy; insured parcels only | 4.5(68) |
 Swiss Chems | Open | — | Per lot; lab not named | Peptides non-returnable | — |
This page contains affiliate links; we may earn a commission. Read the Peptide Sciences review for what we could and could not confirm.
How to choose a replacement
- Start with testing. Prefer vendors that list a COA per lot and name the lab: on our check, PSPeptides, Core Peptides and American Peptides did both.
- Read the refund terms. They range from refund requests within 30 days to all sales final.
- Check lost-parcel cover. Biotech Peptides says it resends lost orders free; several others do not address lost parcels at all.
- Identify the company. A business address and phone number are published by Biotech Peptides, Core Peptides and American Peptides.
- Compare price last, per mg, once the checks above are met.
Full checklist: how to tell if a peptide vendor is legit.
Frequently asked questions
Did Peptide Sciences shut down?
Third-party sources report that its website went dark on 6 March 2026 with a notice that the company had voluntarily shut down. We could not confirm this with the company itself.
What should I look for in a replacement vendor?
A certificate of analysis for each lot that names the lab, a written refund and reship policy, a company name and address, and clear shipping terms. Compare price per mg only after those checks.
Is a site using the Peptide Sciences name the same company?
Not necessarily. A well-known name that has gone quiet is easy to copy. Check the domain, the company details and the COAs before ordering from any site using the name.