From Reflex Wiki
The Megahealth is a pickup in Reflex:
- It adds 100 health to the player's current health, up to a maximum of 200 HP.
- It respawns at mapstart and 30 seconds after the carrier took 100 damage (overhealth tickdown counts).
If your health is above 100 you loose 1 HP/sec until it is at 100 again.