There is strong evidence that Onion Oil treats hair loss. It contains nutrients like Vitamin C, Vitamin B9( Folate), Potassium, Vitamin B6 and so many other compounds. The beauty benefits of it is linked to the root strengthening of the hair. Hence, Prevents Hair Loss. This served as an anti-inflammatory, antioxidant, fungicidal and antibacterial treatment. Especially when it is used in the form of Oil. This acts upon the scalp and hair.