However, there is a chance to reverse your hair cycle when it's a vellus hair. For many individuals, hair reverts from terminal hair to vellus hair before the hair follicle completely dies. Terminal hairs are the thick, long and dark hairs that have fully matured. Vellus hairs are short, thin, lightly-coloured hair that develops on the human body in childhood. Vellus hair has a similar structure to terminal hair and both types of hair grow from a hair follicle. The most common form of hair loss, male pattern baldness, can affect both men and women. This type of baldness occurs when a hormone called Dihydrotestosterone (DHT) attacks the hair follicle. This hormone weakens the hair, causing it to turn thin and brittle, and eventually fall out. If hair regrows, it may be weaker vellus hair rather than terminal hair. Many treatments for baldness attempt to convert vellus hair back to terminal hair by preventing DHT from attacking the hair.
Can Onion Juice reverse the process and turn vellus hair into terminal hair?
Well it may have have worked for someone but is it effective? To be effective something needs to have a degree of success when producing a certain result. When referring to over the counter medicines, if the product had 80%+ effectiveness then it is seen by doctors as an effective cure to whatever they are treating. Therefore, onion juice as a remedy for hair loss may be effective, but it's not effective enough! While it might work for one person, it may not work for the next thousand people.
There has not been any supporting evidence to suggest Onion Juice working as a hair loss remedy for enough people. To be consider effective it needs to work 80% of the time. So it may have worked for someone but if that is only 1 in 1,000 people then it can hardly be called effective !