Allicin is a sulfur-containing compound derived from garlic (Allium sativum), known for its antimicrobial properties. The use of garlic, and by extension allicin, in supporting or treating bladder infections (urinary tract infections, or UTIs) is primarily rooted in traditional medicine. Historically, garlic has been used across various cultures for its general ability to combat infections. Allicin, in particular, has shown broad-spectrum antibacterial activity in laboratory (in vitro) studies, including against some common urinary pathogens like Escherichia coli. However, there is a lack of robust clinical evidence specifically supporting allicin's efficacy in treating bladder infections in humans. Only a few small or preliminary studies have explored garlic extracts for UTIs, and these are not sufficient for definitive conclusions.

Most of the current support for allicin in bladder infections comes from traditional use and laboratory research, rather than large-scale human clinical trials. As such, while the antimicrobial properties of allicin are scientifically plausible and supported by laboratory data, its direct application and effectiveness in treating bladder infections in people remain unproven. For now, its use is best characterized as traditional, with limited scientific validation.