Core Peptides vs SwissChems — US head-to-head 2026
Core Peptides (US-domestic, 6.7) and SwissChems (US-shipping, 7.7) are the two most-discussed US peptide vendors. They differ on catalog scope (peptide-only vs SARMs+peptides), affiliate commission (10% vs 20%), domestic vs international warehousing, and regulatory profile. This head-to-head compares them across the methodology axes.
Catalog scope: Core Peptides is peptide-only (BPC-157, TB-500, GHK-Cu, Selank, Semax, Epithalon, growth-hormone secretagogues, melanotans, etc). SwissChems is dual-catalogue — SARMs (Ostarine, RAD-140, LGD-4033, etc) plus peptides. The dual-catalogue brings broader product range but attracts more regulatory attention because SARMs are state-scheduled in California and several other states.
Testing: every certificate on Core Peptides' product pages is a Vanguard Laboratory HPLC-UV/VIS report — identity by match to a reference standard on most lots, plus chromatographic purity (98.46% to >99.80% on the lots PeptideGuide lists) — with no mass-spectrometry identity or endotoxin result (92 certificates read 2026-10-30). SwissChems ships HPLC + LC-MS verified at 99.3% stated purity. On the methodology SwissChems has the deeper testing (8/10 against Core Peptides' 5/10). Neither has documented third-party blind multi-lab testing.
Affiliate commission: SwissChems 20%, Core Peptides 10%. SwissChems has the highest affiliate commission in the US segment, making it the favoured choice for content creators. PeptideGuide discloses every affiliate relationship at /disclosures and the methodology weighting puts trust + testing ahead of commission.
Regulatory profile: Core Peptides operates peptide-only with strict research-use-only labelling. The peptide-only catalog has cleaner regulatory profile. SwissChems' dual SARMs+peptides catalog brings more enforcement attention. The broader US-segment enforcement pattern is consistent: vendors with dual-catalogue or therapeutic-claim positioning face higher regulatory risk than peptide-only RUO-compliant operators.
Verdict: Core Peptides wins for US-domestic researchers prioritising regulatory cleanliness, fast shipping, and peptide-focused operation. SwissChems wins for content creators (highest commission) and researchers needing broader catalog including SARMs. Both are operationally sound; the choice depends on use case.
✓Pros
- Core Peptides: peptide-only catalog — cleaner regulatory profile
- Core Peptides: US-domestic 2-4 day shipping, no customs
- SwissChems: 20% affiliate commission — highest in US segment
- SwissChems: broader catalog including SARMs
×Cons
- SwissChems: dual SARMs+peptides catalog attracts more regulatory attention
- SwissChems: SARMs state-scheduled in CA + others — verify locally
- Core Peptides: smaller catalog than SwissChems
- Core Peptides: HPLC-only certificates — no mass-spec identity or endotoxin result
- Both: no third-party blind multi-lab testing
Should content creators use SwissChems for the affiliate?
SwissChems' 20% commission is the highest in the US segment. For affiliate-driven content, that's a meaningful revenue advantage. Disclosure is required under FTC Endorsement Guides (16 CFR Part 255) — see /disclosures.
Is the SARMs catalog risky for me?
Buying peptides from a SARM-selling vendor doesn't turn the peptide into a SARM. SARMs are state-scheduled in California and several other states; peptides are not. The dual-catalogue puts more regulatory attention on the vendor (and could disrupt supply continuity if enforcement hits) but doesn't change the legal status of the peptide you ordered.
Why does SwissChems score higher than Core Peptides?
Testing depth. SwissChems ships HPLC + LC-MS verified certificates (testing 8/10); Core Peptides' certificates report HPLC only (testing 5/10, purity 8/10). Core Peptides still scores higher on regional fit, and both sit at trust 6, but testing and purity together carry half of the methodology weight. Composite: SwissChems 7.7, Core Peptides 6.7.
Can I order from both?
Yes. You can order from both, for example SwissChems for SARMs or for products Core Peptides doesn't carry. PeptideGuide has no data on how many buyers do this.
What if I see a US vendor that is not on PeptideGuide's leaderboard?
Two reasons a US vendor would not appear in the ranked tier: (1) PeptideGuide methodology requires published per-batch CoAs as a floor — a vendor without published per-batch CoAs scores 3/10 on the testing axis and is listed outside the ranked tier with that gap stated (Pepsup, added September 2026, is the current example); (2) a vendor that stops trading is moved to exited status and leaves every ranked surface. A documented FDA Warning Letter or operational problem does not remove a vendor: it is shown as a warning on the card and, when it forms an open incident, caps the trust axis at 3/10 (2/10 when critical) — SwissChems is ranked #3 with exactly that warning. If a vendor you're considering is not on the list, the absence is intentional.
More from this region.
Other articles covering this region's vendors, regulatory framework, and research peptides.
- 2026-11-02Earlier versions said many US researchers use Core Peptides as their primary vendor and SwissChems as a secondary one. PeptideGuide has no data on this; the claim was removed.
- 2026-10-31Earlier versions gave SwissChems a higher composite and compared testing with a 7-parameter blind multi-lab protocol at Particle Peptides. SwissChems now scores 7.7 after its value axis was re-priced, and Particle Peptides is tested by a single independent laboratory (testing 9/10).
- 2026-10-30Earlier versions said Core Peptides ships HPLC + LC-MS + endotoxin verified COAs and outscores SwissChems. The 92 certificates linked from its product pages (Vanguard Laboratory, read 2026-10-30) report HPLC-UV/VIS only; re-scored on that evidence, it ranks below SwissChems.