No. It is an absolute that cannot be substantiated, and it also trips ad policy at Meta and Google, so it costs you the ad account as well as the substantiation argument. Remove it. A money-back guarantee is a refund policy and can be stated as one; it is not a results claim.
Unsubstantiable absolute; also an ad-policy trigger.
We file this under false regulatory and rate it high. It is enforced by FTC, Meta, Google, which matters because a single phrase can fail in more than one place at once: a listing suppression, an ad-account review and a warning letter are three different consequences of the same sentence.
This is the rewrite an audit ships for this phrase, in the words we would hand you.
Remove. A money-back guarantee is a refund policy, not a results claim.
Every structure/function claim on this page still needs the FDA disclaimer wherever it appears. That requirement has its own ruling.
Run one ASIN through the free check. You get the severity counts on your own copy, ruled against all 92 standards, with no sales call attached.