It's probably not inherently surprising to discover that stress causes gray hair—but in a groundbreaking discovery, a new study confirms that removing stress can reverse the graying process, actually changing the root color of white or gray strands back to their original hue.

That's right—reducing stress can reverse your grays.

It's hard to believe, but it's true: In a study published in eLife, researchers plucked 397 hair samples from the heads of 14 healthy people ranging in age from 9 to 39, all of whom identified as having some gray hairs or two-colored hairs (yes, amazingly, even in the 9-year-old). Researchers then asked subjects to keep a stress diary, looking back at their calendars to identify periods of extreme stress they experienced over the course of a year.

By plucking and digitally imaging the hairs and comparing them to the subjects' stress diaries, researchers were able to match stressful life events with specific pigmentation sections of their hair, which they termed "bioarchives," similar to a storage site for biological information.

Hair can store information

It turns out your hair can hold more than secrets: "Just like tree rings hold information about past decades, and rocks hold information about past centuries, hairs hold information about past months and years," wrote the study's senior author, Martin Picard, PhD, associate professor of behavioral medicine (in psychiatry and neurology) at Columbia University Vagelos College of Physicians and Surgeons.

Using the information found in the donors' hair strands, scientists found that in 10 of the 14 participants, a reversal of graying occurred: some hairs had a white portion at the top, but were growing back darker at the bottom—or undergoing "repigmentation."

And for one participant, this repigmentation corresponded directly to the time he was on a two-week vacation.

If you needed yet another way to use a vacation as a scientifically proven way to reduce stress, consider this your sign.

Stress causes gray hair

Stress has long been thought or assumed to cause graying, but shockingly, to this date, it had yet to be proven in human studies. But a closer look at the hair pigmentation patterns in comparison with reports of stressful times in hair donors' lives "showed striking associations," writes Dr. Picard.

"When one donor reported an increase in stress, a hair lost its pigment. When the donor reported a reduction in stress, the same hair regained its pigment."

It's important to note that the graying reversal happens to the portion of hair that's still under the skin—the follicle. This means that if you have a full head of gray hair, it's unlikely you'd see a reversal. "When hairs are still under the skin as follicles, they are subject to the influence of stress hormones and other things happening in our mind and body. Once hairs grow out of the scalp, they harden and permanently crystallize these exposures into a stable form," writes Dr. Picard.

Gray hair can be temporary

But where the real hair-raising feature (pun intended) of this study lies is that there's a threshold for temporary graying: "If hairs are about to go gray anyway, a stressful event might trigger that change earlier. And when the stressful event ends, if a hair is just above the threshold, then it could revert back to dark," notes Dr. Picard.

This is all to say that yes, you can and should take that vacation to potentially reduce your chance of going gray early. The verdict is still out on whether or not you should bring your kids with you.


Rosenberg AM, Rausser S, Ren J, Mosharov EV, Sturm G, Ogden RT, Patel P, Soni RK, Lacefield C, Tobin DJ, Paus R. Quantitative mapping of human hair greying and reversal in relation to life stress. eLife. 2021 Jun 22;10:e67437. doi:10.7554/eLife.67437