Pigmentation: behind the scenes

Author Dr. Tiina Meder
Founder and CEO of Meder by Dr Tiina Meder skincare brand

Pigmentation remains one of the most misunderstood areas in dermatology and skin biology. It’s easy to see pigment merely as a side effect of sun exposure, yet this view vastly underestimates the skin’s intricate protective systems. Let’s explore the complex world of pigmentation—its origins, functions, and the fascinating biological mechanisms beneath the surface.

Melanocytes: The Unsung Heroes

Pigmentation originates from melanocytes—specialized cells responsible for producing melanin. Beyond determining skin, hair, and eye color, melanin also plays roles in the inner ear, nervous system, and even the heart. Variations in melanin levels explain the difference between blue and dark eyes or the diversity of hair colors across populations.

Melanocytes are not evenly distributed throughout the skin. While their density can vary by body area, all people—regardless of race, gender, or age—possess roughly the same number of pigment cells. What differs is how these cells are activated and function. Interestingly, melanocytes resemble neurons (1), earning them the nickname “nerve cells of the skin” because of their structure and responsiveness to emotional and physiological stimuli. They regulate autophagy (2) —the programmed death of cells—and are central to skin detoxification and aging processes.

Melanin’s Role: Beyond Skin Color

Melanocytes live for decades (3), from embryonic development into old age. However, their pigment-producing activity doesn’t begin immediately after birth. During early childhood, these cells mature and become capable of defending the skin. This highlights the importance of shielding infants from sunlight—especially in their first year—since their natural protection is still developing.

Once mature, melanocytes transfer melanin granules to the upper layers of the skin, forming protective “umbrellas” above cell clusters. They reside in the basal layer of the epidermis, where each melanocyte connects with 30–40 keratinocytes, forming an epidermal melanin unit (4). The ratio of melanocytes to keratinocytes—1:10 in the basal layer—remains stable throughout life, although the precise regulation mechanism remains unclear. These melanin shields act as the body’s first defense against UV radiation, pollution, and reactive oxygen species.

Melanocytes, keratinocytes, and dermal fibroblasts constantly communicate through secreted molecules and direct contact (8,9). Keratinocytes regulate melanocyte activity, while both cell types produce local hormones that influence melanocyte proliferation, pigment synthesis, and dendrite formation. In aesthetic medicine, pigmentation treatments often target melanocytes alone, yet effective therapy must also address keratinocyte and fibroblast signaling.

With age, melanocytes decline — around 10% are lost each decade after age 30. As a result, protection weakens, leaving both young children and older adults more susceptible to UV and environmental damage.

The Chemistry of Pigment

Melanin synthesis begins with the amino acid phenylalanine, which converts into L-tyrosine and then into melanin through the enzyme tyrosinase. This enzyme exists across many life forms, including plants and fungi—nature’s shared defense mechanism. People with darker skin types have more active tyrosinase, resulting in up to ten times more melanin production than lighter skin types. Those with red hair predominantly produce pheomelanin, which is lighter and offers less UV protection.

Depending on the biochemical environment, melanin can develop as either golden pheomelanin or brown-black eumelanin. This depends on how tyrosinase interacts with antioxidant molecules such as cysteine, glutathione, and thioredoxin. In the absence of these antioxidants, eumelanin forms; in their presence, pheomelanin dominates. This balance defines skin tone diversity and underlies conditions like freckles, age spots, and hyperpigmentation.

Melanin and Skin Protection

Melanin’s role extends far beyond pigmentation—it absorbs harmful UV radiation and disperses it as harmless heat (10). Acting as a powerful antioxidant, it protects DNA, cell membranes, and cellular integrity. Melanin offers natural cancer resistance while allowing the synthesis of vitamin D and mood-enhancing endorphins during sunlight exposure. Therefore, complete sun avoidance isn’t the answer; balance and protection are key.

Pigmentation Triggers: Ultraviolet Plus Five

While ultraviolet radiation remains the primary pigmentation trigger, at least five additional factors influence the process:

• Hormonal influences: Estrogen and cortisol stimulate melanin production, while progesterone provides mild protection yet enhances estrogenic effects (11).
• Stress: Chronic stress promotes pigmentation and inflammation, increasing susceptibility to melasma and other skin disorders (12).
• Inflammation: Skin inflammation—from diseases, trauma, or medications—accelerates pigment formation and aging (10).
• Lifestyle: Pollution, smoking, alcohol, poor diet, sleep deprivation, and frequent outdoor exposure all contribute to pigment irregularities.
• Microbiome: An imbalanced microbiome can intensify melanogenesis, resulting in hyperpigmentation (13).
  

Managing hyperpigmentation requires addressing not only UV exposure but also hormonal balance, stress, inflammation, and lifestyle factors.

Hormones and Pigment Regulation

Hormones are powerful regulators of pigmentation. The melanocyte-stimulating hormone (MSH), produced in the brain, is activated by UV exposure and influenced by sex hormones. Women on hormonal contraceptives or during pregnancy often develop melasma—the “pregnancy mask.” This condition, more common in Mediterranean and Middle Eastern populations, reflects genetic predisposition, UV exposure, and hormonal shifts.

Inflammation: The Dark Side of Pigmentation

Several medications—including antibiotics, contraceptives, retinoids, antihistamines, and antidepressants—can heighten skin photosensitivity, increasing pigmentation risks. Aggressive skincare treatments, like exfoliation, chemical peels, or lasers, can promote renewal but also trigger inflammation. Skin disorders such as acne, eczema, or insect bites frequently result in post-inflammatory hyperpigmentation, which is persistent and challenging to manage.

The Microbiome: The Hidden Layer of Protection

Healthy skin hosts beneficial bacteria that reduce inflammation and help prevent pigment formation. In contrast, an imbalanced microbiome allows pro-inflammatory microbes to thrive, exacerbating pigmentation. Research shows that darker, spot-prone skin tends to harbor more opportunistic pathogens, while lighter, clearer skin has bacteria with antioxidant and UV-protective functions. Certain species, like Sphingomonas and Erythrobacteraceae, can produce UV-protective compounds, reducing damage during sun exposure. These distinct microbial communities vary depending on pigmentation status, suggesting that maintaining microbial balance might function as a natural sunscreen. Ongoing research continues to explore its diagnostic and therapeutic potential (14).

The Spectrum of Pigmentation

Pigment changes range from melasma and pregnancy masks to age spots, periorbital darkening, and pigment loss from trauma or autoimmune diseases such as vitiligo and albinism. Pigmentation reflects the skin’s overall health—a visible response to internal and external influences.

Moving Forward

Achieving true skin health means understanding the full network of pigmentation triggers—UV radiation, hormones, inflammation, lifestyle, and microbiome. Pigmentation is dynamic and complex, deserving thoughtful and comprehensive care rather than simplistic solutions.

Meder Dr. Tiina Meder

In her skincare line Dr. Tiina Meder putted all this knowledge and deep understanding of pigmentation into 2 products — cream Lumino-Derm Ld7 and complementary mask Lumino-Derm Mask Ld5.

Lumino-Derm Cream

Lumino-Derm Cream targets excess pigmentation safely and effectively, brightening the skin through advanced peptides, skin-identical ingredients, and botanical extracts.

As the first brightening cream powered by biotechnology, Lumino-Derm calms the skin, strengthens its defense against UV damage, and suits all skin types. It delivers an even, radiant tone without the halo effect or increased sensitivity.

The formula combines cysteamine, tranexamic acid, pre- and probiotics, organic licorice extract, and the innovative X50 peptide—delivered via a precision “cosmetic drone” system to target dark spots directly.

Hypoallergenic and suitable during pregnancy and breastfeeding, Lumino-Derm offers year-round radiance and balanced, luminous skin.

Lumino-Derm Mask

Lumino-Derm Mask is a revolutionary brightening sheet mask with potent brightening and anti-inflammatory ingredients. The powerful formula includes biotechnological and organic ingredients. Natural probiotics sourced from lactic bacteria (the same ones you find in your Greek yoghurt) moisturise skin and restore healthy microbiome. Innovative peptides eliminate pigmentation and visibly brighten skin. Alpha-arbutin sourced from bearberries and red grape resveratrol help restore natural skin tone, make it more even and bright without whitening or halo effect. Hypoallergenic and suitable for all skin types, Lumino-Derm sheet mask is safe to use during pregnancy and breastfeeding when women often experience higher risk of pigmentation. Highly effective mask is also gentle to your skin and doesn't increase sun sensitivity, so you won't need to up your SPF. Lumino-Derm sheet mask prevents the appearance of pigmentation, calms and hydrates skin leaving it soft, smooth, even-toned and radiant.

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