Neem (Azadirachta indica) has a long history of use in traditional Indian medicine (Ayurveda) for oral health, including the management of halitosis (bad breath). In recent years, scientific studies have provided some validation for its use in this context. Neem possesses well-documented antimicrobial properties, particularly against bacteria implicated in oral infections and malodor, such as Streptococcus mutans and Porphyromonas gingivalis. Several in vitro studies demonstrate that neem extracts can inhibit the growth of these organisms and reduce volatile sulfur compound (VSC) production, which is a primary cause of halitosis.

Clinical trials, while somewhat limited in number and size, have shown that mouthwashes or chewing sticks made from neem can reduce plaque, gingivitis, and oral bacterial load, all factors associated with halitosis. For instance, a few randomized controlled trials have found neem-based mouth rinses to be as effective as chlorhexidine in reducing oral malodor and improving overall oral hygiene, with fewer side effects.

Nonetheless, the overall body of evidence is still moderate, with a need for larger, well-designed clinical trials to establish neem's efficacy specifically for halitosis. While the tradition is strong, it is the emerging scientific literature that increasingly supports neem’s use for this indication, warranting a mid-level evidence rating.