Dakota Johnson Uses This Growth-Boosting Serum for Her Iconic Liquid Hair—I'm Buying 3

There’s not much we miss when it comes to Dakota Johnson and her effortlessly chic style choices. Whether she’s spotted wearing a new denim hue on the set of Verity or inspiring us with her long, liquid hair on red carpets, we’re quick to analyze the details of the 35-year-old actress’ looks—and since arriving in Cannes for the 2025 Film Festival, she has not disappointed.

Johnson graced the red carpet for her Splitsville premiere donning a fringe-dripped, ballerina-pink Gucci gown complemented by her fluid brown tresses. While we’ve always associated Johnson with her long, healthy hair, she reached Rapunzel status today with her pin-straight mane falling past the waistline of her gown. Her secret, according to celebrity stylist Mark Townsend? The hair growth brand that editors love and Sofia Richie relied on for thick, healthy postpartum hair: Nutrafol.

“For Cannes, I knew I wanted to keep Dakota’s look timeless and elevated,” Townsend tells Who What Wear. “We went with smooth, sleek, straight hair—an effortlessly elegant look that lets her natural beauty shine.” Inspired by Johnson’s fringey gown, the stylist shaped her thick bangs and cascading strands into a long, glassy sheet to “counterbalance” the look. “No extensions, it’s all hers!,” he gushes.

If this last comment made you mentally will your hair to grow faster, we’re right there with you, but Townsend explains that the trick to fairytale length is proper care—specifically concerning strand and scalp health. Though Johnson’s schedule has been packed with travel for red carpet events, movie shoots, and Cannes prep, Townsend was able to nurture the star’s strands with Nutrafol’s Hair Serum, which he calls a “non-negotiable” in his kit.

This hair serum is a go-to for celebrity hairstylists because of its lightweight formula that absorbs quickly without leaving the roots or scalp feeling greasy—making it great for both hair growth and strand-smoothing (a huge perk for hectic red carpet prep).

“I’ve tried many serums over the years, but what sets this one apart is how well it works in tandem with Nutrafol’s supplements,” says Townsend, going on to say that he, too, regularly takes the growth-stimulating supplements that Richie relies on. “Nutrafol’s Hair Serum beautifully complements the internal support of the supplements. Especially for red carpet prep, when the hair is under heat, tension, and often subject to multiple looks in a short time, that kind of care is essential,” he adds. “I never leave for a job without it!”

The serum’s formula, engineered by physicians and clinically tested, is strong-armed with ashwagandha exosomes (proteins and lipids that encourage healthy, shiny hair), Irish moss peptides (supports hair strength), and pea sprout extract (to improve thickness). All it takes is one dropper’s full a day on the scalp, concentrating on any thinning areas, to generate visibly stronger, healthier, and thicker results after approximately 90 days of regular use. Pro tip: You can smooth the extra residue on your hands through your hair to achieve Johnson’s sleek, liquid strands.

Aside from glass hair results, Townsend relies on this serum for the strand-saving measures that celebrity hair often requires—especially when it comes to big moments like the Cannes Film Festival. “When sleep is irregular and jet lag sets in, it can show up on the hair,” he explains. “Supporting hair from the inside out makes all the difference.”

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