Thousands of women are burning their hair with candles as part of a trendy but bizarre beauty treatment

A Brazilian beauty treatment known as velaterapia is gaining popularity thanks to Victoria's Secret models like Alessandra Ambrosia and Barbara Fialho.

Ambrosia was the latest to Instagram the hair treatment, spotted by BuzzFeed, but Fialho was the first to popularize the hair burning trend online back in 2014 when it was covered by everyone from The Daily Mail to Fashionista.

The idea behind velaterapia is that it burns off split ends and makes hair look smooth and shiny. One Brazilian spa called Laces describes the treatment as "cauteriz[ing]" the hair:

It is a process where a flame cauterizes the hair, leaving behind a passage of nutrients to its interior, removes split ends and the impermeability of the hair caused by brushing and other chemicals.

First, the hair stylist divides and twists the hair into small sections. Then, they take a lit candle to the hair, carefully moving it up and down the twisted section.

The process looks something like this:

YouTube

Velaterapia takes between two to three hours and can be done on any type of hair, from dyed to straightened, according to Laces salon. It's said to be especially effective for "dry and damaged hair that combats the stress caused by chemical treatment, dying, and constant styling," according to Elle magazine.

The treatment has been popular in South America since the 1960s, according to The Daily Mail, where women frequently try to do the dangerous hair treatment by themselves at home. 

Of course, not everyone is a fan of the bizarre trend. 

"While burning split ends might remove the split in the hair, you are also creating a potential vulnerability to the fiber itself, which results in weaker strands," Elizabeth Cunnane-Phillips, a trichologist at the Philip Kingsley Clinic in NYC, told Refinery 29. "There are a lot more effective ways to remove split ends than to burn it off. I would say, don't take the risk."

But if you do want to give this Brazilian beauty treatment a try, all sources said that it's best to do velaterapia in a salon with an expert.

And for those worried about the smell of burning hair or lighting themselves on fire, it's best to stick with a trim.