Dungeon Master's Guide
Potion, Rare
When you drink this potion, your Strength score changes to 23 for 1 hour. This potion has no effect on you if your Strength is equal to or greater than that score.
This potion's transparent liquid has floating in it a sliver of fingernail from a Frost or Stone giant. The potion of frost giant strength and the potion of stone giant strength have the same effect.