Potion for Dreamless Sleep

Potion for Dreamless Sleep is a purple potion that puts the drinker into a deep sleep without dreams (GF36).

References from the canon

• After Harry's encounter with Voldemort in the graveyard during which Cedric Diggory was killed, and then the revelation that Barty Crouch Jr. was masquerading as Mad Eye Moody, Harry was exhausted but still had to tell the story to Dumbledore about Priori Incantatum, the Reverse-Spell Effect.
• Afterward, he was given this sleeping potion by Poppy Pomfrey. The potion was purple in a small bottle, and Harry was told to drink all of it, but he only managed a few sips.
• Effect: Harry felt drowsy and warm, as if "sinking deeper into the warmth of the feather mattress" (GF36).
• He was wakened  a few hours later by an argument between Minerva McGonagall and Cornelius Fudge, who had called a Dementor to the castle to suck out Barty Jr.'s soul. Then Snape showed Fudge the burning Dark Mark on his arm, but Fudge refused to believe that Voldemort had returned.
• After Fudge left and all the Order members went their separate ways, Mrs. Weasley gave Harry the rest of his potion and instantly "heavy, irresistible waves of dreamless sleep broke over him" (GF36).
• Inconsistency: On Pottermore, the potion was identified as "Sleeping Draught" but when the bottle was collected it was called "Potion for Dreamless Sleep" (Pm).