Melatonin is a hormone secreted by the pineal gland in the brain in response to darkness. It helps regulate hormones and maintain the body’s circadian rhythm. i.e., the sleep-wake cycle.

There are a number of new reports that suggest that melatonin has some benefits for those sufferring from hair loss and thinning. Make sure to also read my post on natural supplements for scalp hair growth.

The sale of melatonin supplements witnessed a major surge during the pandemic due to an explosion of cases of insomnia. Production of this important hormone declines with age.

Melatonin and Hair Growth

In a recent article on First for Women, board-certified dermatologist Dr. Jose Diego Mier praised topical melatonin for its hair growth effects. Among the interesting reasons he mentioned (some proven, some not) include:

• Melatonin is a powerful antioxidant that can be used to protect hair follicles from oxidative stress. This includes from exposure to pollution and ultraviolet (UV) radiation.
• The presence of melatonin receptors on the scalp suggests that this hormone has a role in hair cell growth.
• Melatonin may extend the anagen growth phase of the hair cycle and also act as a counter to dihydrotestosteone (DHT).
• There are not enough studies to draw any firm conclusions. However, per Dr. Mier, from what scientists can see now, it is clear that melatonin positively affects hair quality.

Recent Studies

A March 2023 literature review identified 11 human studies that included subjects with alopecia who were also applying topical melatonin. Eight of the studies noted positive outcomes after topical melatonin use in subjects with androgenetic alopecia (AGA) compared with controls.

Improved scalp hair growth was reported in all eight studies, improved hair density in four, and increased hair shaft thickness in two. Both topical and oral melatonin were utilized depending on study. Topical can take the form of serum, solution, cream and spray.

A May 2022 study from South Korea found that melatonin increasesthe volume of human dermal papilla spheroids by activating the Wnt/β-Catenin signaling pathway. This in turn induced hair regrowth. These results revealed that melatonin plays a role in human dermal papilla cells.

In July 2020, scientists from Poland published an important paper titled: “Hormonal effects on hair follicles.” Section 3.5 in the paper is devoted to melatonin. I found the links to prolactin and estrogen of interest:

1. Melatonin can directly and indirectly regulate hair growth. The direct effect is via the modulation of the serum prolactin.
2. An important activity of melatonin is its ability to modulate the response of hair follicles to estrogens.