From Brotato Wiki
Blood Donation
Item
Tier 3
Stats
+40 Harvesting
You take 1 damage per second (does not give invulnerability time)
You take 1 damage per second (does not give invulnerability time)
Price
50
Item
Blood Donation 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.