Biophysics of Sun and Skin Interaction

The Skin’s Biophysical & Biochemical Adaptations to Sunrise and UV Light


Phase 1: Sunrise (Infrared & Red Light, No direct UV Yet)

Sun Angle: 0–10°

• Filaggrin Activation & Natural Moisturizing Factor (NMF) Formation

• Filaggrin breaks down into urocanic acid (UCA), amino acids, and minerals to strengthen the skin barrier.

• Natural Moisturizing Factor (NMF) increases hydration and enhances UV resilience.

• Exclusion Zone (EZ) Water Expansion

• Near-infrared (NIR) light builds structured water layers in skin cells, improving hydration and reducing oxidative stress.

• This water acts as a photonic energy capacitor/buffer, preparing to capture incoming UV exposure (further preparing/building skin resilience).

• Nitric Oxide (NO) Release & Microvascular Priming

• Red/NIR light liberates NO from skin, increasing blood flow and oxygenation.

• Enhances UV tolerance by improving circulation and reducing inflammation.

• Cholesterol Sulfate Formation & Hormonal Signaling

• Red light primes cholesterol for sulfation, preparing for Vitamin D3 sulfate production under UVB later in the day.

• Cholesterol sulfate maintains cell membrane integrity and skin hydration.

• Tyrosinase & Melanin Activation

• Red/NIR light primes melanin production, helping safely distribute UV energy later.

• Copper-dependent tyrosinase enzyme begins melanin biosynthesis.
  
  

Phase 2: UVA Emerge (10–15° Sun Angle, Direct UVA Reaches Skin)

Sun Angle: 10–15°

• Urocanic Acid (UCA) Activation

• UCA absorbs UVA, acting as a natural photoprotective filter.

• UV-induced isomerization converts trans-UCA into cis-UCA, further modulating protective immune responses.

• Alpha-MSH Release (Melanocyte-Stimulating Hormone)

• UVA stimulates α-MSH, increasing melanin production. This only occurs when the eyes also see this light at the same time the skin does. (Key: No sunglasses)

• Protects DNA and mitochondria from oxidative stress by enhancing melanin synthesis.

• Beta-Endorphin Release (from UVA-POMC interaction)

• UVA light triggers β-Endorphin production, modulating pain perception, stress adaptation, and immune response further enhancing upcoming UVB tolerance.

• Histidine Conversion to Histamine (Pink Flush Response)

• UVA causes vasodilation, allowing more nutrients and repair factors to reach the skin.

• Pink flush indicates capillary expansion and adaptation, but excessive histamine can signal overexposure. This is what happens when you get sunburned (along with excessive ROS/RNS free radical stimulation and excessive RNA activation.
  
  

Phase 3: UVB Emerge (30° Sun Angle, Direct UVB Reaches Skin)

Sun Angle: 30°

• Vitamin D3 Sulfate Production Begins

• UVB converts 7-dehydrocholesterol into Vitamin D3, which binds sulfate to remain water-soluble.

• This supports immune function, testosterone synthesis, and overall skin health.

• Increased Electron Absorption by Melanin

• UVB charges melanin with stored energy, allowing controlled photonic release over time.

• Protects DNA by absorbing high-energy UV photons and redistributing them safely.

• Increased Structuring of Body’s Water Networks

• UVB further expands the exclusion zones (EZs) or coherent domains (CDs) which further charge the body’s biological battery allowing more energy to be stored within the living system.

• Final Tuning of Hormonal Signaling

• UVB exposure enhances testosterone production via cholesterol metabolism.

• Insulin sensitivity improves, aligning metabolic function with solar energy cycles.

• Controlled Oxidative Stress Triggers Hormesis

• UVB generates mild ROS (reactive oxygen species), stimulating mitochondrial adaptations strengthening the skin.

• This builds resilience, enhances cellular redox balance, and prevents UV damage over time.
  
  

Conclusion

This stepwise adaptation to sunlight forms a solar callus, optimizing the skin’s ability to absorb light, produce essential hormones, and prevent damage. Each phase primes the next, ensuring the skin can harness UV energy safely while strengthening its resilience against environmental stressors. Experiencing every degree of sun exposure from sunrise to 30 degrees on eyes and skin allows this cascade to occur optimally for best biological results.