Start with the paperwork, not the price
The single biggest signal of a trustworthy retatrutide listing is whether a certificate of analysis (COA) is available for the specific batch being sold, not just a generic one attached to the product page. A COA confirms what’s actually in the vial: purity, concentration, and confirmation the product matches its label.
What a real COA includes
A usable COA names the testing lab, the batch or lot number matching the vial in hand, the test date, and the measured purity percentage. A COA with no batch number, or one that’s clearly reused across every listing on a site, isn’t verifying anything specific to the product being shipped.
Delivery and handling matter as much as the lab report
Retatrutide, like other peptides, needs to be kept cool during transit. A supplier shipping without any cold-chain measures, especially during warmer months, risks degrading the product before it arrives regardless of how clean the original lab result was.
Questions worth asking before ordering
Whether the batch has a matching COA available on request, how the order ships (insulated packaging, ice packs), what the typical UK delivery window is, and whether the supplier has a way to verify a specific vial against its documented batch. A supplier that answers all of these clearly is a stronger signal than reviews alone.
Red flags
Prices dramatically below the rest of the market, no COA offered at all, vague batch numbering, and no way to contact the supplier before ordering. None of these alone is proof of a problem, but together they’re worth treating as a reason to look elsewhere.