seeing a new variant of the old myths floating around, this one claims it only "works" the first time and never again after. sounds like nonsense but curious if theres any real basis or if its just a new coat of paint on on old lore.
no solid basis I'm aware of for a one-time-only mechanism specifically. more likely explanation is expectation and novelty doing a lot of the perceived difference between a first and later experience, not the compound itself changing how it interacts with you.
Agree with Jules on the mechanism point, and I'd add that if someone's genuinely tracking a change in their own response over repeated occasions, that's worth raising with a doctor rather than explaining it away with forum folklore either direction.
Convenient claim for anyone trying to get you to buy something "new and improved" for the next round though
yeah that's kind of where my radar went off too idk