Anti-Radiation Pills are an item found in RUST that immediately removes 25 points of radiation upon consumption.
The drawback is that the Anti-Radiation Pills also removes 10 points of hydration on each use. However, you can mitigate this effect by drinking water from a River, Lake, Small Water Bottle, Bota Bag, or Water Jug, as this will also reduce your radiation.
You can add the pills to your hotbar for immediate consumption with a hotkey. However, keep in mind that taking too many Anti-Radiation Pills can dehydrate you quickly.
Dehydration will slow you down, and reduce your health recovery, so pair the pills with water whenever you take them.
The Anti-Radiation Pills are ideal for environments where radiation levels are so high that you take radiation damage even when wearing a Hazmat Suit.
You will often find Anti-Radiation Pills in ration boxes. However, they are incredibly cheap to purchase from the Bandit Camp monument.
Make sure to pack a few when visiting places like the roof of the Launch Site monument.