Melatonin is a naturally occurring hormone primarily recognized for regulating the body’s sleep-wake cycle, or circadian rhythm. Produced mainly by the pineal gland, its secretion is tied to darkness, signaling the body to rest. However, this molecule is also synthesized in other areas, including the skin and hair follicles. This widespread presence has led researchers to investigate whether melatonin can effectively stimulate hair growth and serve as a treatment for hair loss.
Melatonin’s Functions Beyond Sleep Regulation
Melatonin’s biological activities extend beyond managing the sleep cycle, establishing a foundation for its potential use in dermatology. Melatonin is a potent antioxidant, meaning it neutralizes harmful free radicals that cause oxidative stress in cells. This function protects cellular components like DNA and proteins from damage.
The hormone also possesses anti-inflammatory properties, helping to modulate the body’s inflammatory response. This dual action helps preserve tissue integrity throughout the body. By reducing oxidative damage and inflammation, melatonin aids in maintaining a healthier cellular environment, which is beneficial for processes like hair growth.
Clinical Evidence Supporting Hair Growth
Research into using melatonin for hair loss has largely focused on topical application, yielding measurable positive results. Clinical trials have demonstrated that topical melatonin can increase hair density, particularly in individuals with androgenetic alopecia (pattern baldness) and telogen effluvium (excessive hair shedding). For instance, one study involving men with androgenetic alopecia found a significant increase in hair density, rising approximately 29% after three months and 41% after six months of treatment.
A large-scale multicenter study involving nearly 1,900 participants reported a dramatic reduction in hair shedding over 90 days. The percentage of patients experiencing moderate or severe hair loss decreased substantially, while the number of participants with no hair loss increased significantly. These findings suggest that melatonin is an effective agent for improving hair quality and reducing the rate of loss. Positive outcomes are based on measurable data from objective techniques, such as TrichoScan analysis and hair-pull tests.
Melatonin’s Interaction with the Hair Follicle Cycle
The positive clinical results are supported by melatonin’s direct interaction with the hair follicle’s growth cycle. Hair follicles cycle through three main phases: anagen (growth), catagen (transition), and telogen (resting/shedding). Melatonin receptors (MT1 and MT2) are present within the human hair follicle, indicating the hair is a direct target for the hormone’s signals.
Melatonin is believed to promote and prolong the anagen, or active growth, phase of the hair cycle. Extending this period allows the hair more time to grow before transitioning to the next stage. It may also help shorten the catagen and telogen phases, reducing the time the hair spends resting or shedding. This protective effect helps maintain the health and viability of the follicle, which is particularly important in conditions like pattern baldness where miniaturization occurs.
Practical Application and Safety Profile
For stimulating hair growth, the primary method of delivery studied is a topical solution applied directly to the scalp. This localized approach ensures the hormone acts directly on the hair follicles without significantly affecting systemic melatonin levels, which could disrupt the normal sleep cycle. Effective concentrations in trials generally range from 0.0033% to 0.1% solution, applied once daily.
The safety profile of topical melatonin is considered favorable, with good tolerability reported across multiple studies. Minor, localized side effects are occasionally reported, such as temporary reddening, mild itching, or irritation on the scalp. Consulting with a dermatologist is a prudent step before beginning any new hair growth treatment to ensure it is appropriate for the specific type of hair loss.