Core Peptides
Established US vendor with strong 'best vendor' list presence and 98-99% purity verified on sampled batches by Janoshik/Peptide Test. Large catalog (103+ SKUs), fast 2-3 day US shipping. But COAs are not hosted batch-traceably on product pages, testing is selective (not every batch), and reviewers note aggressive affiliate programs inflate community reputation — so transparency lags its reputation.
Score breakdown
Strengths
- Large catalog (103+ SKUs), competitive mid-range pricing
- 98-99% purity from independent labs (Janoshik, Peptide Test) on sampled batches
- Fast US shipping (2-3 days), responsive support, multiple payment methods
Weaknesses
- No hosted/searchable per-batch COA library; lot numbers absent from product pages
- Selective (not 100%) third-party testing; no endotoxin/sterility data published
- Reputation partly affiliate-inflated per reviews; no on-site reviews to verify
How we rank
One formula, the same for every vendor including our partner. Argue with the weights — that's the point.
Overall = 0.40 × Transparency + 0.30 × Purity + 0.15 × Shipping + 0.15 × Value
Core Peptides: 0.40×4.5 + 0.30×7 + 0.15×8 + 0.15×6.5 = 6.1
How each axis is scored
Transparency (×0.4). COA depth, named third-party labs, breadth of test types (HPLC base; +MS, +LAL, +heavy metals, +sterility), public batch traceability. Claim-only purity (no hosted PDF) caps this axis.
Purity (×0.3). Median/recent batch purity from hosted COAs + independent lab confirmation (Finnrick/Janoshik). Self-reported '99%+' with no batch PDFs scores low.
Shipping (×0.15). US-domestic speed/reliability and stock consistency from real shipping data; international-only or undisclosed scores lower.
Value (×0.15). Purity-adjusted price per mg vs the cross-vendor median for the same peptide/vial; discount-dependency penalized.
Reviews
Why trust this comparison
- Every vendor is scored from real evidence on four public, weighted axes — before we know any margins.
- Purity claims are cross-checked against named third-party labs (MZ Biolabs, Finnrick, Janoshik). Claim-only purity is marked as such.
- The scoring code can't read which vendor pays us — the editorial-commerce firewall is enforced in software.
- We disclose the 20% / 10% Alpha Pro commission on every page, above the first link.
Vendors out-rank our own partner: Peptide Partners (9.0) and Protide Health (8.9) and Ascension Peptides (8.8) both score above Alpha Pro (8.6). We left it that way.