"You turn into a newt
! Your armor
falls around you! You find you must drop your weapon
"Do you want your possessions identified?
Don't drink this in a combat situation unless you are truly desperate, as noted above.
This one of the only NetHack potions I can think of where blessed/cursed status is completely irrelevant. You quaff, you polymorph. You throw it at something else, they polymorph. Remember that polymorphing occasionally causes a system shock that deals you 30 damage immediately.
This potion is ineffective if you possess the unchanging intrinsic.