What it means
Prescription (Rx) medicines need a licensed prescriber because they need medical judgment to use safely. Over-the-counter (OTC) medicines have been shown safe to use with the label alone.
For weight loss, the only FDA-approved OTC medicine is orlistat 60 mg, sold as Alli. Every GLP-1 medicine, including the Wegovy pill and Foundayo, requires a prescription.
Dietary supplements are a third category. They do not need FDA approval before sale, and makers do not have to prove they work. The FDA has found hundreds of weight-loss supplements containing hidden drug ingredients, some of them banned.
A product sold without a prescription and claiming to work "like a GLP-1" is either a supplement making a marketing claim or an unapproved drug. Neither has the trial evidence behind approved medicines.
Why it matters
If a website offers a GLP-1 medicine without any prescription step, that is a sign the product is not legitimate.