Melanin is one of the body’s most important natural protection systems. It is a pigment produced by specialised cells called melanocytes, found mainly in the epidermis (the outer layer of the skin). Melanin helps determine skin colour, hair colour and eye colour, but its role goes far beyond appearance. Its primary biological purpose is protection.
When skin is exposed to ultraviolet (UV) radiation from sunlight, melanocytes respond by increasing melanin production in a process called melanogenesis. This is the body attempting to defend itself from further UV damage. The increased pigment absorbs and disperses ultraviolet radiation before it penetrates deeper into the skin and damages DNA.
This is why tanning occurs. A tan is not healthy skin in the true sense — it is a visible biological stress response where the skin increases melanin production in an attempt to protect itself from further injury.
There are two main types of melanin in human skin:
• Eumelanin — brown to black pigment
• Pheomelanin — yellow to red pigment
Eumelanin is considered far more protective because it absorbs UV radiation efficiently and helps neutralise oxidative stress caused by sun exposure. People with higher levels of eumelanin generally have darker skin tones and naturally greater protection against UV-induced damage.
Pheomelanin, more common in very fair skin and red hair, provides less UV protection and is less photostable. This partly explains why lighter skin types often burn more easily and may have a higher risk of cumulative sun damage over time.
Importantly, all humans have a relatively similar number of melanocytes. The difference in skin tone comes mainly from:
• how much melanin is produced
• what type of melanin predominates
• the size and distribution of melanin granules within the skin.
Melanin acts almost like a biological umbrella over skin cells. It helps reduce:
• DNA damage
• oxidative stress
• inflammation
• premature collagen breakdown
• visible photoageing.
However, melanin is not complete protection. Even darker skin tones can experience:
• UV damage
• pigmentation disorders
• collagen degradation
• skin cancers including melanoma.
The risk profile differs, but no skin type is completely immune to sun damage.
Modern skin science also recognises that pigmentation is influenced not only by sunlight, but also by:
• inflammation
• hormones
• heat
• visible light
• oxidative stress
• genetics
• certain medications and health conditions.
This is why conditions such as melasma, post-inflammatory hyperpigmentation and uneven pigmentation can become chronic or recurrent if underlying triggers are not addressed.
A balanced educational message around sun exposure is important. Daylight itself is essential for human health. Early morning natural light helps regulate circadian rhythm, sleep quality, mood, hormone signalling and overall wellbeing. The goal is not fear of sunlight — it is understanding appropriate exposure, skin protection, and cumulative damage over decades.
Healthy sun habits involve:
• avoiding excessive burning
• supporting the skin barrier
• using antioxidants and SPF appropriately
• respecting individual skin biology
• understanding that prevention is easier than reversing long-term UV damage later in life.
