Be Careful With Consuming Herbs
You can’t actually pick up herbs and store them in your inventory in Umbrella Corps. Instead, enemies will randomly drop them once you kill them, and you walk over the herbs to consume them. Unfortunately, the game is designed such that you can still ‘use’ these herbs even if you’re at full health. This means that if you miss a herb sitting right in front of you, and you walk over it while at full health, you’ll consume it, and the herb will essentially be wasted.
Keep a keen eye out for the green herbs that drop from enemy bodies, and make sure to keep away from them if you’re at full health. A good tactic is to make a mental note of where the herb drops are, and then if you’re ever in trouble in the middle of the level, you can run back to your herb locations and quickly use them to regain all of your health.