Goose Bumps Could Hold Key to Stimulating Hair Growth


By Kevin Ritchart

You might be familiar with the phrase “bald is beautiful,” but a team of stem cell researchers could be very close to finding definitive proof that “scary equals hairy.”

Harvard University’s Ya-Chieh Hsu has found that the nerves and muscles responsible for raising goose bumps in the skin also can stimulate cells to make hair follicles and grow hair. She reported her findings in December 2018 at a joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization.

Hsu suspects that getting goose bumps when it’s cold could cause animals’ fur to grow thicker.

The sympathetic nervous system controls a number of important functions of the body that we don’t have to think about, including heart rate, dilation of the pupils in your eyes, and other automatic processes.

The sympathetic nerves located next to hair follicles are wrapped around tiny muscles known as arrector pili. When these muscles contract, they make the hair cells stand on end. This is what causes goose bumps.

Sympathetic nerves situate themselves next to the stem cells that can eventually create hair follicles, Hsu’s team found. Stem cells are unspecialized cells that can mature into many different types of cells. While much of the research is still in its infancy, scientists are constantly working on new and innovative uses for stem cells.

Typically, nerves are wrapped in a protective coating of myelin, much like the plastic outer coating on electrical wires.

In this case, researchers observed that the ends of the nerves are exposed where they meet the hair-follicle stem cells. The nerves secrete norepinephrine, a hormone that plays a part in the body’s many involuntary reactions, like the acceleration of your heart rate when you’re scared or nervous.

Hsu’s team also found that norepinephrine is necessary for hair growth. This could explain why hair loss is a side effect of heart drugs known as beta-blockers since they interfere with the distribution of norepinephrine in the body.

Mice with genetic changes that kept the arrector pili muscles from growing didn’t have the corresponding sympathetic nerves. They also didn’t grow hair normally. Like the genetically altered mice, men with male pattern baldness don’t have arrector pili muscles in their scalps. This told Hsu and her team that sympathetic nerves and the muscles that cause goose bumps might be important in the diagnosis and treatment of this type of baldness.

Restoring the nerves and muscles in the scalp may eventually lead to new hair growth, which may give doctors another treatment option for baldness.

Discussion Questions

  • What are some other applications for stem cell research?
  • Do you know of any other automatic processes in the human body that are controlled by the sympathetic nervous system?


  • Myelin
  • Norepinephrine
  • Arrector Pili