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How to verify a supplement you bought on Amazon is genuine

A five-step check for commingled inventory

Short answer: check that the listing shipped from the brand or an authorized seller, then match the batch or lot code on the bottle you received to a public lab certificate for that batch. If the code matches a real certificate from a named lab, the bottle is genuine. If the code is missing, unreadable, or matches nothing, consider the certificate chain unverified and contact the brand.

Why Amazon is a special case

Amazon uses commingled inventory: when a listing is fulfilled by Amazon, units from many third-party sellers of the same product can be pooled in one bin. That means a bottle listed under the official brand can physically originate from a seller the brand never authorized. This is the most common source of authenticity complaints shoppers raise about supplements bought online.

The five-step checklist

What each outcome means

If the lot code matches a public certificate from a named, accredited lab, the bottle is genuine and you are done. If the brand publishes certificates but none matches your lot, the bottle is unverified, and the brand's support team can confirm whether that lot is theirs. If the brand publishes no independent certificate at all, there is nothing to verify against, which is a gap in the brand's transparency rather than a judgement on the bottle.

The shortcut

ScanCheck automates steps three and four. It holds a live index of 20,407 public certificates across 1,174 brands. Point your camera at the label: a green verdict means the brand has a public independent certificate on file, shown with the batch, lab, date, and method. Amber means the brand is indexed but this batch is not on file yet, so you can request it. Red means no public independent certificate exists to check against.

Related: how to tell if a Certificate of Analysis is real.

Frequently asked

Does Amazon mix inventory from different sellers?
Yes. Under commingled inventory, units of the same product from different third-party sellers can be pooled together, so a bottle on a brand listing can originate from an unauthorized seller.
How do I match a bottle to its lab certificate?
Read the lot or batch code stamped on the bottle and find the published certificate that carries the same code from a named, accredited lab. Matching codes is what ties the report to the bottle in your hand.
What if there is no code on the bottle?
A missing or covered lot code means you cannot tie the bottle to any certificate. Contact the brand with your order details before relying on it.
Is buying direct from the brand safer than Amazon?
Buying from the brand or a brand-authorized seller removes commingling risk, because the units are not pooled with third-party stock of the same listing.
Check supplements by lot number with the ScanCheck app Free on the App Store Get app