What Harvard’s New Hair Loss Study Suggests

Can Stress Actually Cause Hair Loss?

You’ve heard of stress shedding, and so had Harvard. For a long time, the hair loss community and experts alike have suspected stress can impact hair loss, but we didn’t know for sure how it affects your hair follicles. Now, Harvard researchers have found an answer.

The Findings

Harvard researchers published a study in the journal, Nature, detailing the biological mechanism responsible for stress-related hair loss in mice. The study found that extended periods of stress put hair follicle stem cells in a longer resting phase, making them dormant for a while. In this phase, hair follicle stem cells are unable to produce new hair.

So What’s The Big Deal?

The study pinpointed the precise cell type and molecules behind stress-induced hair loss and proved that the pathway can be redirected to restore hair growth!
Hair loss history has repeatedly shown us that, when it comes to hair loss, understanding the mechanisms behind it are key in finding ways to treat it. For example, understanding DHT’s role in male pattern hair loss led to DHT blockers like Finasteride as a treatment for the condition. This study has uncovered the mechanism behind stress-induced hair loss, and it has given the scientific community a starting point for potential treatments.

How Exactly Does Stress Shedding Happen?

Your hair follicles are one of the few human tissues that can regenerate. Thanks to hair follicle stem cells, they go through cycles of rest and regeneration. When they’re in the resting phase, they lose hair strands more easily, and do not regrow a replacement.

The latest research out of Harvard University found that in mice with chronic stress, hair follicles stayed in the rest phase for longer than they otherwise would. The study concluded that this extended dormant phase is all thanks to the mouse stress hormone, corticosterone. The human equivalent of this hormone is called cortisol, and you’ll find it in abundance in people under stress.
Elevated levels of this stress hormone affect the tissue surrounding the hair follicles. Under normal circumstances, the tissue around the follicles secrete a molecule called Gas6 that activates the stem cells and gets them into the growth and regeneration stage of the hair growth cycle. The higher levels of corticosterone prevented the scalp tissue from secreting Gas6, leaving the follicle stem cells without a ‘wake-up’ signal to get back into regrowth. As a result, they stayed in the rest phase for longer.

What Are The Implications For Hair Loss?

The study was conducted on mice, and a lot more needs to be done before we know how to apply the findings to humans.
We can’t say for sure how the findings will affect us. But, we can say with certainty that pinpointing the Gas6 molecule and the stress hormone corticosterone as key players in stress shedding, has put us on the path towards finding treatment for stress-induced hair loss and other stress-related health concerns.

In Conclusion

The Harvard study is a thrilling event for the hair loss industry and community. Not only did the team of researchers confirm that stress directly impacts hair growth, but they also pinpointed the biological mechanisms behind stress shedding. More research needs to be done, but the findings may just be integral in finding treatments for stress-related health problems!


The articles published by &BAM are for informational purposes only and do not constitute medical advice. If you have any medical questions or concerns, you should contact your doctor.

  1. https://news.harvard.edu/gazette/story/2021/03/researchers-discover-how-chronic-stress-leads-to-hair-loss/
  2. https://www.nature.com/articles/s41586-021-03417-2