The Main Reason Your Hair Isn't Growing, According to Julia Roberts's Colorist

"Lasting results of your color or chemical process is greatly improved when the hair is in a healthy state before, during and after the service," says Nawrot. To avoid further damage, treat your split ends before you got to your colorist or technician, applying a once a week protein treatment to prepare your lengths and ends for your service." She says this one by Phyto is rich in essential fatty acids to repair damaged and split hairs.

Nawrot is also a fan of adding protective elements to in-salon chemical processing. "During your service, request a protective treatment to be added to your formula that nourishes while your hair is processing," she instructs. She says these handy oil ampoules are perfecting for boosting hydration and protecting your scalp and hair without disrupting your service.

Olaplex is one of the more well-known salon-add ons for protecting hair during bleaching, color and chemical processing. It's a patented three-step system that essentially repairs broken hair bonds and allows stylists to take their clients all over the hair color spectrum without completely destroying their hair. The first two steps of the Olaplex system are only available to salon pros, but you can purchase the third step, Bonder No. 3, without any professional credentials to maintain healthy, strong hair.

Moisture is among the most important factors in keeping color-treated hair from descending into splitsville. This affordable hair mask is a tried-and-true option that delivers olive, meadowfoam, and sweet almond extracts to seal and nourish the hair.

This protein-rich, argan-oil-infused hair mask help to repair dry, compromised hair. The hydration boost is essential to maintaining processed hair.

According to Lee, the weather has a huge impact on split ends. "Winter will always be the worst season for split ends," she says. She even prescribes a specific, gentle styling regimen to her clients, to stave off the adverse effects dry weather can have on the hair. "At our atelier, we use Aquis towels exclusively because they are way gentler on the hair. It was a pricier inItial investment for our business, but we see a huge overall difference in the health of all of our client’s hair. Plus they just feel luxurious," she says.

Also included in Lee's harsh weather styling regime is a good detangler. "Always use a leave-in spray detangler," she implores. "One that is super lightweight but works extremely well is the Aloe Vera Detangling Spray from Christophe Robin." The ingredients include soothing aloe vera and flaxseed to sooth both the hair and scalp.

But cold weather isn't the only element that can take a toll on your strands. "It is easily forgotten that just like your skin, you need to shield your locks from UV rays and environmental elements that can weaken your hair and cause split ends," says Nawrot. "Keeping your hair protected is vital to the overall health, especially at the ends. Apply a UV Protector when exposed to the sun."

Nawrot also recommends an antioxidant booster for hair that's exposed to environmental stresses and pollution. This one employs vernonia, grape polyphenols, vitamin-rich peptide, acacia collagen, hyaluronic acid, and milk thistle.

This anti-breakage deep conditioner is invisible so you can pop it in and cover with a baseball cap before you head out of the house, or even keep it in your beach bag to quickly apply if your hair gets soaked with salty or chemical-filled pool water.

"This is actually a pre-treatment and is most potent when used pre-shampoo for about 20 minutes with heat," says Lee. 

Lee also swears by this healing oil, which contains tocopherol, Tahitian gardenia flower extract, and Kalahari melon seed oil to protect, strengthen, and shield against moisture loss. Lee recommends a focus on the ends of the hair to keep split ends at bay.

Rosehip oil, algae extract, B vitamins, and almond oil make this mask a deeply nourishing split-end smoothing treatment that can revitalize even the most parched tresses.

"Whether you shampoo daily or less frequently, the most vital thing you can do to your hair daily is to hydrate it," says Nawrot. "Lack of moisture causes the hair to become more porous and can lead to split ends. Use a daily hydrator on your lengths and ends to keep your hair shiny and healthy."

This luxurious mask is like a drink of water for your hair. It's got deeply regenerating oils like cupuacu oil and manketti oil for seriously hydrated strands. Use it as a pre-treatment before you shampoo or leave it on for a deep conditioning.

"Not addressing your split ends can cause undue stress to your hair during heat styling, resulting in further damage," says Nawrot. "Mechanical heat styling can also be the culprit in causing split ends. Your hairdryers and hot irons create great effects, but if your hair is not protected, you are at risk each time you use them. Always use a leave-in thermal protector before you heat-style."

Lee also points out that people are more inclined to go harder on the heat tools during colder months when folks are less likely to let their hair air-dry for fear of catching a chill. She loves that this dry oil spray is packed with hair-protecting ingredients like vegetable proteins, cedar bark, Tsubaki oil, and prickly pear.

This keratin-and–marula-oil spray simultaneously smooths ends and offers thermal heat protection so your end result is shiny, frizz-free hair.

Another Phyto favorite, this luxe styling cream can protect the hair during heat styling up to 430 degrees.

Here's another serum from Lee's split end-fighting arsenal. Pea protein, hydrolyzed quinoa, and baobab seed oil help to smooth frizz, seal splayed ends, and protect the entire hair shaft from heat, making this little bottle a must-have for anyone who uses dryers or irons to their hair regularly.
Up next, having a baby ruined my hair—here are nine ways I'm salvaging it.
This article was originally published at an earlier date and has been updated.