Annonacin is a natural acetogenin primarily found in plants of the Annonaceae family, such as soursop (Annona muricata) and custard apple. It has attracted significant scientific interest due to its potent neurotoxic effects, including inhibition of mitochondrial complex I, which disrupts cellular energy production in neurons and may contribute to neurodegenerative conditions similar to Parkinson’s disease. As a result, it is widely used in neuroscience research to model neurodegeneration, study mitochondrial dysfunction, and investigate neuronal death mechanisms. Additionally, annonacin shows potential as an anti-cancer agent in laboratory studies, where it inhibits the growth of certain cancer cells, particularly breast and liver cancer cells. Despite these properties, its neurotoxicity poses serious health risks; traditional uses in herbal medicine containing annonacin are now questioned for safety, and applications involving human consumption are strongly discouraged. Its insecticidal effects are also under exploration for natural pesticide formulations.