The Anabolic Accelerant is a piece of REACT Tech Gear in Rainbow Six Extraction, which is unlocked at Tech Tier 4 when you reach Milestone 18 and, like all REACT Tech, can be developed using one REACT Token. The in-game description of the Anabolic Accelerant is a little vague, leaving many players unsure how to use it. The fact is that you don’t “use” the Anabolic Accelerant, as such. It has a passive effect that triggers automatically when the required conditions are met.
If you have the Anabolic Accelerant equipped, it will automatically activate if and when your total HP drops below 50. Your total HP is your actual HP (the large number next to your Operator’s portrait in the bottom-left corner of the screen), and any Health Boost you might have (the blue “+XX” after your actual HP). The Anabolic Accelerant will slowly replenish your HP until the total is back up to 50. By “slowly” we mean, by our estimation, 3 HP every 8 seconds. So if, for example, your actual HP drops to 1, the Anabolic Accelerant will give you a maximum HP boost of 49. There is no limit to how much it can do this — it doesn’t ever run out but, of course, your Operator’s HP still can. While the Anabolic Accelerant can’t take your HP above 50, you can still use Medkits to boost your HP even higher.