while I think it’s effects should stay hidden because for a new player it becomes somewhat obvious that they either boost stats or increase infection. However, I gotta agree with Hail that we should get a stat screen. I’d love to know a concrete number or at least a tracker of some kind.
If there's a stat screen, it could be, say, a room in the decaying building that has some sort of fitness analysis machine, maybe also solar-powered in some way so that it's not necessary to use batteries (but with the setup being far too big and heavy to carry back to the base). That way you get to show all relevant stats to the player (like strength and fluid volume out of max, for example) without making it easy to micromanage the hell out of it, and it would fit decently in the game's own story.