Hemlock (5e Equipment)
From D&D Wiki
Price per dose: 200 gp
Hemlock poison is extracted from the poisonous varieties of apiaceae. The plant has a smooth green hollow stem, usually spotted or streaked with red or purple on the lower half of the stem. It disrupts the central nervous system and even small doses can result in respiratory collapse and death. The poisons in hemlock are so deadly that people have died after eating game birds that had eaten hemlock seeds.
1d6 hours after ingestion, the subject must pass a DC 14 Constitution saving throw or take 14 (4d6) poison damage. If the saving throw is failed by 5 or more, the subject also falls unconscious for 1 hour.
If the subject takes charcoal tablets within 1 hour of the initial ingestion, they have advantage on the saving throw.