Onions’ health properties mean the vegetable may offer a bevy of benefits for the hair. "Rich in antioxidants and flavonoids, onions offer antimicrobial, antifungal, and anti-inflammatory benefits," says Kerry Yates, a trichologist and founder of Colour Collective based in Dallas. These properties make it a potential solution to alleviate fungal infections that can cause dandruff, she adds. While there’s a lack of high-quality research on how these properties translate to your scalp, one review published in 2020 in the Journal of Pharmacy and Bioallied Sciences noted the antifungal and antimicrobial potential of onion extract and onion essential oils.