I. purpurea does not sequester ergot alkaloids in its seeds unlike the other Ipomoeas.

Wink, Michael & Ben-Erik van Wyk (2008). Mind-Altering and Poisonous Plants of the World. Timber Press p.150

Seed, a diuretic and laxative. Has been used to treat oedema, oliguria, ascariasis, constipation, to expel parasitic worms (Yeung. Him-Che. Handbook of Chinese Herbs and Formulas. Institute of Chinese Medicine, Los Angeles 1985). The seed also contains small amounts of the hallucinogen LSD(Duke. J. A. and Ayensu. E. S. Medicinal Plants of China Reference Publications, Inc. 1985 ISBN 0-917256-20-4)

https://pfaf.org https://pfaf.org/user/Plant.aspx?LatinName=Ipomoea+purpurea#:~:text=Ipomoea%20purpurea%20is%20a%20ANNUAL,flower%20from%20July%20to%20September.