Human breast milk is a complex biological fluid produced to nourish a rapidly developing infant. Its composition is highly dynamic, changing from the initial colostrum to mature milk, and contains a blend of fats, proteins, vitamins, and immune factors. This rich mixture has led to an anecdotal belief that applying breast milk directly to the scalp can promote hair growth or increase thickness. To understand the validity of this popular remedy, it is necessary to examine the specific components of the milk and the biological process of hair growth itself.
Key Biological Components of Breast Milk
Among the most relevant components are various growth factors, which are naturally occurring proteins that stimulate cell division and differentiation. The most prominent of these include Epidermal Growth Factor (EGF) and Insulin-like Growth Factor (IGF-I). These factors are present in human milk in varying concentrations, with colostrum typically containing higher levels than mature milk. Beyond these, breast milk contains components like lactoferrin, immunoglobulins, and fatty acids, which contribute to immune function and cell membrane synthesis. It is the presence of these potent, growth-promoting peptides that fuels the idea of using breast milk as a topical treatment for hair.
Understanding the Hair Growth Cycle
Hair growth is a highly regulated, cyclical process involving the hair follicle, a structure embedded deep within the skin’s dermis. This process occurs in three main phases: anagen, catagen, and telogen. The anagen phase is the active growth period, where cells in the hair bulb divide rapidly to produce the hair shaft. Following this is the catagen phase, a brief transitional period during which the hair follicle shrinks and detaches from its blood supply. Finally, the telogen phase is a resting period where the old hair remains anchored before shedding to make way for a new hair shaft to begin the anagen phase.
Evaluating the Topical Application Claim
The theory that breast milk can stimulate hair growth relies on the assumption that its concentrated growth factors can reach and positively affect the hair follicle. However, several biological hurdles challenge the efficacy of this topical application. The primary barrier is the scalp’s outermost layer, the stratum corneum. Growth factors like EGF and IGF-I are large protein molecules, making them poorly suited for passive absorption through the skin’s protective lipid-rich matrix. Although the hair follicle can provide a pathway for some penetration, the size of these peptides limits their ability to reach the deep dermal papilla where hair growth is regulated.
Standard topical application is unlikely to deliver these components to the location where they would need to act to prolong the anagen phase. Another complicating factor is the concentration of these growth factors in the milk itself. While they are present, the concentration may not be sufficient to induce a measurable biological change when applied externally, especially compared to their intended function when ingested by the infant. The beneficial effects of these compounds are often observed in in vitro studies or when they are actively delivered to the target tissue, such as the intestinal lining.
Currently, there is a lack of rigorous, peer-reviewed scientific studies or clinical trials that have demonstrated breast milk’s ability to promote hair growth on the adult or infant scalp. While there is research suggesting that exosomes found in colostrum, which are tiny vesicles containing growth-promoting signals, may accelerate the hair cycle transition from telogen to anagen in animal models, this work is preliminary and does not involve the simple application of mature human breast milk. The anecdotal use of breast milk for hair growth does not have a confirmed mechanism of action that overcomes the significant barrier function of the scalp skin.