Gender Change Potion

Character sprite set and hurt sounds, and that is essentially the whole list. It sticks until you drink another one. A handful of NPCs read your character differently in conversation, the Stylist most noticeably, but nothing in combat, crafting or progression cares.

It wants one of every herb in the game, which for a fresh character means a lot of walking for a cosmetic change. Early in a run it is honestly faster to make a new character and move your gear across. The calculation flips completely once you have an alchemy plot with all the herb types planted, at which point you can brew a shelf of them and stop thinking about it.

The Garland is the only other recipe that asks for every herb, which is a strange pair of items to have that in common.