SCP-686 is a white liquid resembling high-grade milk but with complex proteins, extra vitamins and minerals. SCP-686 causes increased lactation in mammals, affecting both genders. Initial symptoms include breast swelling and nipple sensitivity, leading to 0.5-1 liter of milk daily. If not milked regularly, mammary development spreads, forming an udder-like structure with 6-8 pairs of teats, producing up to 40 liters daily. The host becomes mentally dull and must eat continuously.