How does deep conditioner really work?

We all know the changing temperatures can wreak havoc on your locks — and deep conditioner is one of the best ways to repair damage caused by cold, dry days. But how exactly does deep conditioning work to repair your hair? Deep conditioner is a moisturizing substance that, when left upon your locks for an extended period of time, works to penetrate the hair shaft and repair breakage within. Each strand of hair on your head is made of a tough protein called keratin, the bonds of which can easily be broken by cold weather, excess heat, chemical products, or other external stressors. Deep conditioner works as a protective coating to fill in breaks in the hair strands. Dermatologist Adam Friedman compared deep conditioner’s effects on hair to cement filling a pothole in a 2018 interview with Allure. “When the hair is exposed to the outside world, the cuticle, or outer lining, [it] gets damaged until it ultimately breaks,” Friedman said. “The conditioner fills in those injuries and coats the hair to assist the cuticle." “Conditioner refortifies the cuticle with a protective coating, allowing the hair to keep growing and not break easily," he says.

Deep conditioner should be left on your strands for anywhere between three and five minutes, and can be applied before or after a shampoo — but the jury’s up on which route is better. On the one hand, some experts say conditioner weighs down your hair, so applying it after you shampoo will eliminate your hair’s volume, causing your locks to fall flat. Others say the shampoo process can strip your hair of oils it needs to prevent breakage, and applying conditioner after restores this moisture. Whichever route you take, it’s always best to use products made with natural ingredients to avoid any possible damage from harsh chemicals. Bartholomew Sisters’ new multi-use deep conditioner is made with five ingredients — shea butter, coconut oil, vitamin E, rosemary oil and oak barrel oil — and that’s it. Whether you place it pre-shampoo or post, you can rest assured knowing your giving your hair the healthy treatment it deserves.