For the people who's not familiarized with the light novels, in the book Margarita has pathological chronic insomnia since she was born to the point she NEVER sleeps. This condition make her quite disconnected with her own humanity, caused several psycological issues, but at the same it made her immune to the poison called GIFT, which made her the ideal candidate for prepare it without any risk.
There's a point in the story where she, in an attempt to conceal the ingredients of the GIFT, ingest them and then distill them from her own blood
