From Brotato Wiki
Item
Adrenaline is an in-game item that can be bought from a Shop or can be found in a Crate. Most Items modify the Stats of the player, and some of them provide additional effects.
Adrenaline
Adrenaline has 50% chance to provide you with a 5 heal when you dodge an attack. This can be a powerful way of healing if you have the maximum amount of dodge, 60% or close to that amount. This can be especially useful on melee builds that are more likely to get hit often such as Brawler. The Character Ghost can reach up to 90% dodge chance, making Adrenaline a powerful option for healing.