Dietary Supplement vs Drug: What Separates the Two Under FDA Rules

The difference is the stated purpose and the proof required. A drug must be shown to work for its use before sale. A supplement is not approved by FDA before it is sold (FDA, Questions and Answers on Dietary Supplements).

FDA explains that a product represented, explicitly or implicitly, for the treatment, prevention or cure of a specific disease is treated as a drug (FDA, Questions and Answers on Dietary Supplements). So the same capsule can be a supplement in one description and a drug in another. The words used to sell it decide.

Yes, and that is the trap. FTC states that a health claim can be made by implication, even when the disease is never named (FTC, Health Products Compliance Guidance).

The label of Reviralis Complete never mentions herpes, outbreaks or flare-ups. The sales page does speak of "outbreak" and "flare-ups" and says the product helps "quiet the internal signal your body sends before an outbreak" (Reviralis sales page). We quote these as the seller's words only. The site does not rule on a legal question, but it does check the words against evidence.

Regulators have acted on products sold online for sexually transmitted infections, and say no over-the-counter or online supplement can treat or prevent them (HIV.gov, FDA and FTC Act on Fraudulent HIV and STD Products).