The Secret Potion

wolfbane - poisonous Eurasian perennial herb with broad rounded leaves and yellow flowers and fibrous rootstock
Aconitum lycoctonum, wolf's bane, wolfsbane
aconite - any of various usually poisonous plants of the genus Aconitum having tuberous roots and palmately lobed leaves and blue or white flowers

This is what Little Red Riding Hood took with her when she visited her psychiatrist. Slipped in his tea. (He shouldn't have shot Granny!)

bane ben n. & v. [OE bana = OFris. bona, OS, OHG bano, ON bani, f. Gmc: ult. connections unkn.] A n. 1 A slayer, a murderer. Long arch. rare. OE. 2 A thing which causes death or destroys life, esp. poison. Long arch. exc. in comb., as henbane, wolf's bane, etc. OE. 3 Murder, death, destruction. ME-M17. 4 Ruin, woe. Chiefly poet. LME. 5 A cause of ruin, harm, or trouble. L16.
2 TOLKIEN The Ring gleamed and flickered as he held it up'Behold Isildur's Bane!' said Elrond. 3 SHAKES. Macb. I will not be afraid of death and bane Till Birnam Forest come to Dunsinane. 4 R. GREENE That sweet boy that wrought bright Venus bane. 5 BURKE Theoretic plans of constitution have been the bane of France. C. BRONTe She who had been the bane of his life. M. M. KAYE His attentions soon became the bane of the boy's existence.