A potion to put others to sleep
In 1999, the Charmed Ones tried to use one of these potions against the evil witch Tuatha. Phoebe smashed the potion bottle at her feet, releasing a white smoke. However, the potion did not affect Tuatha and she merely pretended to yawn. She then used a similar potion of her own to put both Phoebe and Leo to sleep.
When the Charmed Ones were sent back in time to 1670, they met a witch named Eva, a member of the same coven as their ancestor Charlotte Warren. To save Charlotte and her unborn baby from the evil witch Ruth Cobb, Eva helped the sisters brew a sleeping potion. However, the potions were not used.
After the Charmed Ones rescued Frank Pirelli from being murdered by the Brotherhood of the Thorn, they took him back to the Manor and hid him from the Demons in their basement. Leo mentioned that Phoebe's sleeping potion worked well on him. 
- In Season 8, Billie Jenkins found a Sleep Spell in the Book of Shadows, though the entry actually describes how to brew a potion.