Researchers have made significant progress in the field of hair loss, finding new treatments and approaches that could lead to a permanent cure for the condition. One study found that the protein Gas6 could activate hair follicle stem cells, promoting hair growth. The research, conducted on mice, needs further work before clinical trials can begin. The study also showed that the muscle surrounding the hair follicle, known as the dermal sheath, could play a role in hair loss and regeneration. The muscle physically drives hair follicle regression, and when it contracts, it squeezes the hair follicle to start the regression process. The same contraction machinery was found in human hair follicles, and if it can be stopped, hair follicle regression could be prevented, keeping existing hair shafts that would otherwise be lost.

Researchers have also successfully grown fully functional mature mouse hair follicles in vitro in the lab, a significant breakthrough that could lead to more effective treatments for hair loss, such as androgenetic alopecia. Researchers hope their cultured hair follicles will be useful for studying hair growth and pigmentation and screening new drugs. However, the follicles do not undergo growth cycles in the same way as normal hair, so it may be necessary to transplant them into living animals to reproduce hair cycles. Researchers have already achieved this with individual follicles containing hair shafts up to 10 millimeters long.

People with pattern hair loss, also known as androgenetic hair loss, are genetically predisposed to have a stronger response to androgens (male hormones) in their scalp. Activation of androgen receptors in dermal papilla cells shortens the growth phase of hair follicles, and in those susceptible to pattern hair loss, excessive activation of the receptor shrinks the follicle, resulting in shorter, thinner hairs. Those with the condition produce more of a potent androgen called dihydrotestosterone (DHT). Two Food and Drug Administration (FDA)-approved drugs for pattern hair loss are finasteride and minoxidil. Finasteride inhibits 5 alpha-reductase to reduce levels of DHT in the scalp. Minoxidil dilates blood capillaries, promoting hair follicle growth by allowing more blood, oxygen, and nutrients to reach them.

In June 2022, the FDA approved the first treatment for alopecia areata, a type of hair loss in which the immune system attacks hair follicles. The drug, baricitinib, had already been approved for rheumatoid arthritis and is taken orally. The research team found that baricitinib worked by inhibiting JAK1 and JAK2, two enzymes that trigger an immune response. Although the drug has side effects, they are considered acceptable compared to the benefits of the drug.

There are other treatments available for hair loss that are not FDA-approved, such as platelet-rich plasma (PRP), low-level light therapy (LLLT), and microneedling. PRP is derived from the patient’s blood and injected into the scalp to stimulate hair growth. LLLT is a painless, noninvasive light treatment that stimulates hair growth by increasing blood flow to the scalp. Microneedling involves creating tiny micro-injuries in the scalp, which stimulate the body’s healing response and promote hair growth. These treatments are not proven scientifically, and more research is needed to establish their effectiveness.

In conclusion, the development of new treatments and the progress made in existing treatments have given new hope to people with hair loss. The discoveries of the protein Gas6, the role of the dermal sheath muscle, and the successful growth of mature mouse hair follicles in vitro in the lab are significant breakthroughs that could lead to new, more effective treatments.