Core Power Peptides
Rank 3 of 4. Documentation score 4 of 6.
The catalog and price we recommend; the paperwork still has real gaps.
Affiliate link. We may earn a commission if you buy. It does not change the rank above.
What the documents show
101 products across a wide catalog, including tirzepatide, semaglutide, cagrilintide and mazdutide, with free US shipping over $100 and stated 2–5 day domestic delivery.
Source: corepowerpeptides.is/The homepage shows one sample COA: purity 99%, lot CP-2510-025, tested 26 October 2025 by Freedom Diagnostics. Unchanged since our first check.
Source: corepowerpeptides.is/Says every batch gets HPLC and mass spectrometry testing and calls its products third-party tested by independent, ISO-certified labs.
Source: corepowerpeptides.is/about/Runs its own affiliate program paying 25% per referred sale, which is how this page is funded.
Source: corepowerpeptides.is/affiliate-registration/Says products are made in FDA-registered, cGMP-compliant labs in the USA. We could not check that.
Source: corepowerpeptides.is/
What we could not confirm
The About page says "Full COA available for every batch. No redacted data, just pure results." The tirzepatide 50mg product page has a COA tab, but it shows no certificate, only a Trustpilot widget; the listing says a COA is "available on request" instead.
There is still no COA library or batch lookup. The /coa/, /lab-tests/ and /lab-results/ addresses return 404.
The one sample COA on the homepage names Freedom Diagnostics and one lot number; we have not seen a report for any other product, including tirzepatide.
We found no full legal entity name or street address, only "Precision Science Labs, CA" in the footer, next to a support email on a different domain than the storefront.
The homepage runs customer testimonials describing personal weight-loss and muscle-gain results directly above a footer disclaimer stating the products are not for human use. We do not repeat those claims here.
Retatrutide does not appear in the catalog, despite a blog post on the site aimed at "retatrutide before and after" search traffic.
How we scored this
The score adds three checks, each worth 0 to 2 points: whether an outside lab wrote the report (see reading a certificate of analysis), whether it names the batch you would receive (see spotting a fake COA), and whether the method is stated (see HPLC and mass spectrometry). The full rules are on our methodology page.
Details
- Lab named
- Freedom Diagnostics (named on one sample COA)
- Method
- HPLC and MS (stated)
- Purity
- The site advertises 99%+ purity, guaranteed. Its one published sample COA shows 99% exactly.
- Company
- Not found on the site
- Affiliate program
- 25% commission per referred sale
- Checked
- 29 September 2026, from the vendor's public pages
These are the vendor's claims and our observations. We have not tested any product. Research peptides are sold for laboratory research only and are not for human consumption.