From Guild Wars 2 Wiki
Before completion: Learning to eat these mushrooms tweaks your adrenal glands, giving you a surge of adrenaline and instantly refreshing your skills.
— In-game description
- Adrenal Mushrooms also refill all profession-specific resources such as Adrenaline, Initiative, Life force and Energy.
- Individual Adrenal Mushrooms have a cooldown of 30s.
- If a skill that summons a creature doesn't have a sequence skill, and doesn't kill the existing creature when the new one is summoned, Adrenal Mushrooms allow having multiple summons at the same time.
- This includes all racial skills that summon a creature or object, Mistfire Wolf, and summoned thieves.
- Fire Elemental Powder and Pocket Jade Armor only allow for one summon between the two consumables at a time.
- Chronomancers can double the number of summons thanks to Continuum Split, allowing a chronomancer to summon up to 16 racial summons, if they have a racial skill that summons 2 creatures in those spots with 3 adrenaline mushrooms in close distance from each other, such as the platform where the tetrad of Mordrem champions is fought.