The hair loss treatment market in the United States reached a staggering $3.6 billion in 2022 and was projected to grow at an impressive rate of approximately 8% annually until 2028. Current solutions for combating hair loss include topical and oral medications, surgical procedures, and laser-based regrowth treatments.
Unfortunately, none of these options is considered ideal due to limited effectiveness, high failure rates, and the expense associated with laser treatments. Consequently, the insufficiency of current treatments has spurred significant funding and innovation in the field of hair growth research.
Until recently, peptides had a peripheral role in hair growth treatment, largely because scientists had a limited understanding of the mechanisms behind hair loss. However, a groundbreaking research article in 2021 unveiled the potential fundamental role of peptides in hair growth and regrowth.
This discovery triggered a surge in research focused on peptides for hair growth, shedding light on the intricate biology of hair growth. Here, we delve into some of the top peptides at the forefront of hair growth research and what they have revealed about this complex process.
The Hair Growth Cycle
Hair growth and shedding follow a three-phase cyclic pattern that applies not only to scalp hair but also to body hair, eyelashes, and eyebrows. These phases are known as anagen, catagen, and telogen. In a healthy hair cycle, hair progresses through these stages seamlessly, without becoming stuck in any particular phase. Hair loss conditions, however, involve premature departure from the anagen (growth) phase and entry into the resting (telogen) phase. This results in a significant reduction or cessation of hair growth, followed by overall thinning as hair sheds and is not replaced.
While the exact reasons for hair being trapped in the telogen phase are not fully understood, there are several clues to potential causes. For instance, the male hormone DHT (a derivative of testosterone) seems to play a significant role in hair loss by diminishing blood supply to hair follicles and potentially increasing inflammation leading to hair loss. Additionally, changes in nutrient delivery to the scalp, possibly caused by altered blood supply or inflammation, can result in decreased levels of essential B vitamins that profoundly affect hair and hair follicle health.
Furthermore, hair loss may be attributed to DNA-level changes. Though the precise mechanisms are still under investigation, scientists speculate that alterations in DNA expression patterns, such as changes in hormone levels like DHT or growth hormone, could impact collagen and elastin production as well as blood vessel supply. Therefore, the root cause of much hair loss may lie in changes to DNA expression patterns that manifest as shifts in hormone levels and blood vessel growth.
It’s worth noting that understanding the cyclic nature of hair growth has had limited utility for scientists, primarily because determining what causes hair follicles to transition between phases has been elusive. Recent research on the adiponectin peptide, however, has provided a glimpse into understanding the mechanisms behind these transitions, offering hope for overcoming hair loss.
Adiponectin
Adiponectin, a peptide hormone produced by white fat cells, has long been of interest to scientists for its roles in glucose and lipid metabolism and its ability to regulate insulin sensitivity. Skin itself contains three adiponectin receptors, prompting scientists to investigate its impact on skin. Their findings indicate that adiponectin promotes the
elongation of hair shafts and increases levels of key growth hormones like vascular endothelial growth factor, insulin-like growth factor-1, and hepatocyte growth factor. Adiponectin treatment also leads to increased mRNA
levels, suggesting potential alterations in DNA expression patterns.
Recently, a synthetic derivative of adiponectin called APN5 has been developed, which binds to the AdipoR1 receptor. AdipoR1 is known to mediate AMPK and PPAR-α activities, both powerful modulators of DNA expression patterns. Research demonstrates that transdermal delivery of APN5 in mouse models activates AdipoR1 and promotes hair growth. Hair follicles in the treatment group transition from telogen to anagen, hinting at APN5 and
AdipoR1’s potential to reverse the quiescence associated with aging and hormone level changes. In fact, APN5 showed hair cycle score improvements comparable to minoxidil and significantly greater than the control group. This research has sparked speculation that minoxidil’s effects on hair growth might also be mediated through the AdipoR1 receptor, opening up exciting possibilities for future hair loss treatments.
BPC-157, a synthetic derivative of a naturally occurring body protection compound, has been found to possess anti-inflammatory and wound-healing properties. Research indicates that it accelerates wound healing, improves vascularity, and reduces tissue damage. Wound healing is closely tied to increased collagen production, a protein found throughout the body, including in hair, where it plays a vital role in protecting hair follicles and supplying essential amino acids for keratin production. BPC-157 boosts collagen formation while also enhancing blood vessel growth, leading to improved nutrient and collagen delivery to hair follicles. BPC-157 isn’t solely one of the leading peptides for hair growth research but also a notable candidate for wound healing, tendon repair, and inflammatory bowel disease research due to its profound healing effects.
CJC-1295, a growth hormone secretagogue, is part of a group of peptides believed to influence head and body hair growth. Research suggests that growth hormone, traditionally associated with muscle and long bone growth, significantly impacts hair growth. Supplementation with growth hormone has been shown to enhance hair growth and reduce DHT concentrations in individuals with growth hormone deficiency. GH deficiency is associated with increased 5-alpha reductase concentrations, the enzyme responsible for converting testosterone into DHT. This correlation aligns with the pattern of hair loss accelerating with age, which corresponds to declining GH levels. Other peptides, such as GHRP-2, GHRP-6, ipamorelin, and sermorelin, may also affect growth hormone levels and hair growth, with CJC-1295 standing out as a prominent representative of this peptide group for hair growth research.
GHK-Cu
GHK-Cu, renowned for its effects on skin health and appearance, is a compelling candidate for hair growth research. This peptide is commonly found in premium cosmetic and hair care products due to its ability to tighten skin, reduce fine lines and wrinkles by increasing collagen and elastin production (both essential for hair growth and strength), and alleviate mottling and hyperpigmentation. GHK-Cu also directly impacts hair follicle thickness.
Several mechanisms contribute to GHK-Cu’s role in promoting hair growth. Firstly, it enhances blood vessel growth, addressing a leading cause of hair loss—diminished blood supply to hair follicles, which occurs with age. In the early stages of hair growth, GHK-Cu stimulates capillary growth to improve nutrient delivery. Secondly, GHK-Cu may reduce dihydrotestosterone (DHT), a primary driver of male pattern hair loss. When combined with other peptides, GHK-Cu can inhibit 5-alpha reductase, the enzyme responsible for converting testosterone into DHT, potentially increasing hair thickness and length. Finally, GHK-Cu is a potent anti-inflammatory agent, which, combined with its other effects, may reduce hair loss, increase hair density, and enhance scalp vascularity.
TB-500/Thymosin Beta 4
TB-500 is derived from thymosin beta 4, and both peptides have demonstrated the ability to influence DNA expression patterns and protein production. Research on thymosin beta 4 indicates that overexpression of this peptide in mice leads to accelerated hair growth, likely due to increased blood vessel growth around hair follicles and enhanced protein expression from DNA alterations.
Recent studies, involving both mice and goats, have unveiled that TB-500 can increase the proliferation and migration of hair follicle stem cells—the cells responsible for generating new hair. TB-500 appears to activate the transition of hair follicles from a quiescent state to one of growth and renewal. By stimulating hair follicle stem cells, TB-500 not only encourages existing follicles to transition from telogen to anagen but also fosters the growth of new hair follicles.
Peptides for Hair Growth Research: A Summary
The peptides discussed above represent just a fraction of those found to positively influence hair growth. Consequently, these peptides hold significant promise in the realm of hair growth research. Particularly, APN5, the synthetic derivative of adiponectin, stands as a remarkable breakthrough in hair growth research, with its findings still in their infancy. Researchers are likely to pursue further investigation and explore how other peptides interact with the AdipoR1 receptor, opening the door to more extensive research into the role of AdipoR1 in hair growth. This, in turn, may lead to the discovery of new molecular targets and the development of additional peptides for hair growth research, ultimately deepening our understanding of the intricate process of hair growth.
