"I don't think they exist here, since no one seems to have heard of them," Hermione murmurs. She'd spoken about this potion to someone before, but she can't for the life of her remember who. She seems to remember a frail-looking young man with an obscured face, but... well, that's neither here nor there. "Dreamless Sleep Potions will knock someone out for quite a bit of time, depending on how strong it is and how much the person manages to drink. If it's just some sort of herbal remedy, that might be safer."

Anything that doesn't involve magic sounds relatively safe to Hermione now, but that's another matter altogether.