Plant-induced chronic hepatotoxicity is mainly idiosyncratic, however, metabolic activation is often implicated.

Prolonged exposure to pyrrolizidine alkaloids leads to hepatic veno-occlusive disease and pulmonary arterial hypertension.

Plant-induced chronic neurotoxicity can result from thiamine depletion, hypothyrosis or disruption of neuronal metabolism.

Aristolochic acids cause interstitial fibrosis and tubular atrophy leading to renal failure, and urothelial carcinomas.

Cannabinoids and certain flavonoids have potent immunosuppressive effects and could be harmful for immunodeficient persons.