Garlic mouthwash shows shockingly strong germ-fighting power: Study
Garlic extract has been found to offer antimicrobial effects that are on par with commonly used antiseptics and disinfectants such as chlorhexidine, according to medical researchers at the University of Sharjah.
The study, published in the Journal of Herbal Medicine, reports that garlic-based mouthwash may produce more discomfort than chlorhexidine but appears to provide longer-lasting residual activity.
"Chlorhexidine is widely used as a gold standard mouthwash but is associated with side effects and concerns over antimicrobial resistance," the authors explain. "Garlic (Allium sativum), known for natural antimicrobial properties, has emerged as a potential alternative."
Systematic Review Compares Garlic and Chlorhexidine
The researchers based their conclusions on a systematic review examining how garlic extract performs against chlorhexidine in clinical settings and whether it can realistically function as an herbal substitute.
Their analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines, which are designed to increase the reliability and transparency of systematic reviews and meta-analyses. The authors also used the PICO framework to structure their clinical research questions.
"A total of 389 articles were identified from six electronic databases in January 2024, and an additional 13 articles were included through manual citation searching. After removing duplicates and applying inclusion and exclusion criteria, only five articles were included," they report.
Review Finds Comparable Antimicrobial Performance
The selected literature consisted of randomized controlled trials and clinical studies with varying designs and low-to-moderate risks of bias. Overall, the authors found that higher concentrations of garlic extract mouthwash showed antimicrobial results similar to those of chlorhexidine.
"The effectiveness varied based on mouthwash concentration and duration of application, contributing to differences in outcomes," the review noted. "Some studies favored chlorhexidine for maintaining higher plaque/salivary pH, while others reported garlic extract to be more effective at certain concentrations. However, garlic mouthwash may cause greater discomfort."
Side Effects and Patient Considerations
Although garlic extract can produce side effects, they are typically milder than those associated with synthetic chemicals. Reported issues include a burning sensation and unpleasant odor, which may influence whether patients are willing to switch from chlorhexidine to garlic-based options.
Even with these drawbacks, the review offers strong support for the clinical antimicrobial activity of garlic extract, reporting "significant reductions in bacterial counts from baseline … suggesting the possible use of garlic extract mouthwash as a viable alternative to chlorhexidine in certain contexts."
The authors recommend additional clinical trials with larger participant numbers and longer follow-up periods to confirm the "effectiveness and improve clinical applicability" of garlic as an alternative to chlorhexidine, which is still considered the gold standard antimicrobial mouthwash.
Garlic's Long History as a Natural Antimicrobial
Garlic has long been recognized as one of the most potent naturally occurring antibacterial and antifungal crops. Scientific interest has focused particularly on allicin, a compound known for its strong antimicrobial activity. Although classified botanically as a vegetable, garlic is commonly used as both an herb and a spice.
Worldwide garlic usage reached about 30 million metric tons in 2024. China accounted for nearly 80 percent of global consumption and production. That same year, the global garlic extract market was valued at more than 15 billion dollars.
Growing Interest in Herbal Oral Care Alternatives
Garlic extracts are widely available in various health products over-the-counter. By comparison, synthetic agents like chlorhexidine usually require a prescription from a dentist or physician.
"Antimicrobial mouthwashes constitute an essential adjunct element in oral and dental care, acting against oral diseases caused by bacteria, fungi, or viruses attacking oral hard or soft tissues," the review states. "Different antimicrobial mouthwashes, whether available over-the-counter or on prescription, can be used in the management of gingivitis, dental caries, periodontal diseases, halitosis, etc."
Evidence Expands but Clinical Gaps Remain
The review points to numerous studies that demonstrate antimicrobial effects of garlic extracts against a wide range of bacteria, fungi, and viruses. It also notes that garlic extract has been explored in areas such as denture stomatitis, dentinal tubule disinfection, and intracanal medication.
"These studies have contributed to understanding the antimicrobial role of garlic extract in comparison to synthetic agents like chlorhexidine," the authors write. "However, most studies are in vitro, vary in methods, and lack clinical standardization, highlighting the need for further research to confirm garlic's efficacy in dental practice. This uncertainty presents a significant gap in the literature on evidence-based antimicrobial therapies."
Reference:
Youmna Ahmed Abdelaal, Heba Talal Saeed, Malak Ahmad Elayyan, Sara Mahmoud Bkairat, Saif Youssef Dib. The Clinical Antimicrobial Efficacy of Garlic Extract (Allium sativum) Compared to Chlorhexidine Mouthwash: A Systematic Review. Journal of Herbal Medicine, 2025; 54: 101053 DOI: 10.1016/j.hermed.2025.101053
