To understand how inhibitor peptides are able to alter pigmentation, it is imperative to understand how melanin is produced within the skin, what causes the overproduction of melanin (hyperpigmentation), and how peptides can play a key role in the regulation of melanin production.
HOW THE SKIN PRODUCES MELANIN
Melanogenisis begins when tyrosine, an amino acid, is stimulated by the pituitary gland and attaches to an enzyme, tyrosinase. After tyrosine and tyrosinase attach, another amino acid, DOPA, is formed. Dopamine is an amino acid neurotransmitter that is also used in the treatment of Parkinson’s disease.1 DOPA produces eumelanin (dark or brown color) or pheomelanin (red or yellow). Once synthesis is complete, melanin granules are packed into vessels called melanosomes. Melanosomes then carry the pigment through dendrites to the keratinocytes.
What causes the overproduction of pigment? There are three distinct causes:
- internal: medications, hormones, inflammation, and cell or mitochondria death (we lose 10 to 20 percent a year of correct DNA melanin after age 35)
- external: excessive ultraviolet exposure, certain cosmetics, toxins, and metals
- metabolism or breakdown of melanin
OVEREXPOSURE TO ULTRAVIOLET LIGHT
Let’s look at the cause that is most researched and well known: overexposure to ultraviolet light. In the event of overexposure to ultraviolet light, the cells become damaged. When the cell is damaged, it responds by creating messages (cytokines, growth factors), which in turn produces the melanocyte stimulating hormone (MSH). MSH is a protective messenger. This messenger binds to a receptor on the melanocyte to produce a response. This response is melanin production (protecting cells from future damage). Once the damaging factor has subsided, the melanin production should no longer be initiated by MSH and the melanin should be broken down and metabolized.
How do inhibitor peptides influence hyperpigmentation? The first goal in addressing hyperpigmentation is to determine the cause. Once this is understood, peptides can be used to block the MSH stimuli at the cell’s receptor. If a peptide can mimic the MSH molecule and attach to the receptor site without actually activating the receptor, the chemical cascade that leads to melanin production can then modulate the overproduction of melanin.
However, it is important to allow the skin to do what it is designed to do. The skin’s primary job is to protect. Therefore, inhibitor peptides do not totally inhibit, but compete for reception binding. This is an important factor because melanin is the cell’s response to protect. However, there are incidences when the message of damage is sent from damaged cells that have not gone through apoptosis (cell death). Ultimately, the goal of inhibitor peptides is to block these messages until the fatally damaged cells eventually die through necrosis and the melanin producing messages die along with them. This is an important component to understand.
This process is an automatic protection mechanism of the skin. Inflammation is not just an occurrence, but a message, and causes an organized, strategic response in the cells and tissues. These messages convey to the cell that damage has occurred. In turn, the cell responds by messaging its shield (melanin) to defend from any further damage.
The second issue involved with melanin is the breakdown or metabolism of the pigmentation. This is the hyperpigmentation or darker brown spots that are visible on the skin’s surface. Keep in mind, the visible discoloration on the surface is approximately 30 to 45 days old (cellular turnover from dermis to epidermis in older clients). As the keratinocyte makes its way to the stratum corneum, it flattens as well as accumulates pigment.2
In summary, inhibitor peptides can play a significant role in the treatment of hyper-pigmented skin conditions. Once the aesthetician understands melanogenesis and the causes of over pigmentation, peptides become the key to successful treatments.
1 Misu, Yoshimi, Goshima Yoshio, and Takeaki Miyamae. “Is DOPA a neurotransmitter?”Trends in Pharmacological Science 23, no. 6 (2002): 262-268.DOI: https://doi.org/10.1016/S0165-6147(02)02013-8(02)02013-8
2 Barrett-Hill, Florence. Advanced Skin Analysis. Virtual Beauty Corporation, 2004.
3 Abdullah, Ahmed. Best Practices in the Treatment of Hyperpigmentation. Skin Inc, Apr 27,
4 Videira, Ines Ferreira dos Santos, Daniel Filipe Lima Moura, and Sofia Magna. “Mechanisms regulating melanogenesis.” Anais Brasileiros de Dermatologia 88, no. 1 (2013): 76-83.
Susan Wade is a licensed aesthetician joining Viktoria De’Ann in 2015 as the director of education and sales after being in the health and education industry for over 18 years. She has a master’s in higher education administration and enjoys sharing her wealth of knowledge with physicians, clinicians, and students nationwide. Wade has a diverse background beyond aesthetics as a college instructor in kinesiology and business and is an owner of a successful sports conditioning business’ and a nutrition coach. Her passion lies in understanding the complexities of physiology, nutrition, and biology and in educating practitioners on how to incorporate these areas to reach better solutions and successful results with their clients.