Fey Whisper (5e Equipment)
From D&D Wiki
Price per dose: 2,500 gp
There exists on the prime material plane a dark red flower called Fey Whisper that springs up near fey crossings. This flower has been known to put the consumer into a trance-like state for several hours. Someone proficient in Survival can find a patch of fey whisper after making a successful DC 24 Survival check. Fey whispers typically grow in patches of 1d4 flowers.
To make the poison, you must dry the flower. After drying completely, crush the petals into a powder, mix with a potion of healing, and boil the substance for an hour, stirring occasionally. After an hour has passed, dry the syrupy liquid and grind it into a fine powder. Up to 2 doses can be made from a single flower. When mixed in liquid, the fey whisper dissolves completely. The consumer will notice an added mild sweetness to whatever they are drinking.
1d6 hours after ingesting fey whisper, the creature must make a DC 21 Constitution saving throw, or become poisoned and unconscious. On a success, they are only poisoned. While the creature is poisoned in this way, it must make a Constitution saving throw once an hour. The DC increases by 1 every hour (maximum 26). While the creature is poisoned in this way, it cannot regain hit points and it takes 2d8 poison damage for each failure. If its hit points are reduced to 0, the creature dies. After 3 successes, the creature is no longer poisoned.