Supplements are used in The Last Of Us Part 2 to learn new recipes and upgrade your character. Check out this The Last Of Us Part 2 supplement location guide to find them all as you are playing. If you miss some you will be weaker down the line.
The Last Of Us Part 2 Supplement Location Guide
In the bathroom up there you can find two pills.
We are updating this guide as we go so check back soon for more.
from GamersHeroes http://www.gamersheroes.com/game-guides/the-last-of-us-part-2-supplement-location-guide/