Neem (Azadirachta indica) has a long history of traditional use in Ayurvedic, Unani, and other traditional medicine systems for treating infections. More recently, scientific studies have investigated its antimicrobial properties. Laboratory research has demonstrated that extracts from neem leaves, bark, and oil possess activity against a variety of bacteria, fungi, and viruses, including common pathogens such as Staphylococcus aureus, Escherichia coli, and Candida species. These effects are attributed to compounds such as nimbidin, nimbin, azadirachtin, and others found in neem.

However, the majority of these studies are in vitro (test-tube) or involve animal models. There are very limited clinical studies in humans assessing neem as a direct alternative or adjunct to antibiotics for treating infections. The existing human data are generally of low quality or involve topical applications for skin infections. Current evidence does not robustly support using neem as a replacement for conventional antibiotics in systemic infections, but it may have a role as a complementary agent, particularly in topical or mild cases, pending further research. Safety and dosage in human use also require more rigorous study.