Consumable items are common in Returnal, and you should use them frequently and wisely to extend your runs.
A consumable is usually easy to spot from a distance because of the orange glow that surrounds it. When you first begin playing, you can equip a single consumable item (or multiple units of the same consumable, such as a minor healing item). As you near the second biome, you will unlock a second consumable item.
When you pick up your first consumable, it automatically attaches to the first available slot. You can equip second and third consumable types to the second and third slots, provided you have unlocked them. The slot you currently have highlighted determines which item you will use when you press the L1 button. If you have multiple slots, press left or right on the D-pad to switch between them.
Make sure the consumable you wish to use is highlighted at all times, or that you have at least highlighted an item you don’t mind losing if you accidentally press the L1 button in the heat of battle.
Some consumable items provide a brief effect. They may refill a portion of your integrity meter or unequip a random parasite or even disable all current malfunctions. Other consumable items provide a perk of some sort for a set period of time, usually 30 seconds.
For instance, an item might erect a barrier that wards off enemy projectiles while enhancing any shots you fire through that same barrier. Or an item might lower your maneuverability but double your damage output, or it might produce harmful shockwaves that damage nearby enemies whenever you jump and land.
If you have your maximum consumables equipped and approach another, you can make a decision about whether to acquire the new one or to keep the consumable you currently have highlighted in your inventory. If your integrity is running low, this might be a good opportunity to use a vial to refill it and pick up a different consumable item, should the opportunity present itself. Always try to make the most of the items offered, but never drop an item you probably need for one you likely don’t.