Is methylene glycol (Brazilian Blowout main active ingredient) for hair straightening is safe?

The safety of using methylene glycol for hair straightening is a topic of some controversy and concern. Methylene glycol is a formaldehyde-releasing agent, which means that it breaks down into formaldehyde when heated or applied to the hair. Formaldehyde is a known irritant and has been linked to several health concerns, including eye, nose, and throat irritation, respiratory problems, and an increased risk of certain cancers.

While some hair smoothing treatments that contain methylene glycol may be marketed as "formaldehyde-free" or "low formaldehyde," they can still release small amounts of formaldehyde when heated or applied to the hair.

It's also worth noting that the use of hair smoothing treatments containing methylene glycol is regulated differently in different countries. In some countries, the use of these products may be restricted or banned, while in others they may be available over-the-counter.

If you're considering a hair smoothing treatment that contains methylene glycol, it's important to weigh the potential benefits against the potential risks, and to discuss your options with a stylist or hair care professional who has experience with these products. They can help you understand the ingredients and any potential health concerns, and can provide recommendations based on your individual hair type and health history.