Hair Health: The Science of Seletividade and Hair Growth

Hair Health begins with a biological reality that most people ignore: capillary seletividade. Have you ever wondered why a “miracle” hair cream works wonders for a friend but leaves your hair oily or brittle? This frustration is rooted in a biological reality called capillary seletividade. According to the structural principles of Clarence Robbins, your hair is not just a fiber; it is a complex, selective structure that determines what penetrates the cortex and what is rejected at the surface.

However, your Hair Health is not just about what you apply externally. Recent research from the BJIHS (2026) highlights that your HPA axis (Hypothalamic-Pituitary-Adrenal) is a major driver of hair vitality. Consequently, if your internal biology is out of sync, even the most expensive treatments will fail to deliver results.

The Science of Seletividade: Porosity and Rejection

Why does hair reject certain products? The answer lies in capillary porosity. Your hair’s cuticle scales act as a gatekeeper. Therefore, the molecular weight of your cream must match your hair’s specific ability to absorb it.

• Low Porosity: The cuticles are tightly closed. As a result, heavy products cannot enter and simply sit on the surface, causing “build-up” that suffocates Hair Health.

• High Porosity: The hair is like a sponge—it absorbs quickly but loses moisture just as fast. In this case, seletividade means you need heavy sealants to lock in hydration.

The HPA Axis: How Cortisol “Shuts Down” Growth

In addition to external care, internal stress is a silent killer of your hair’s growth cycle. When chronic stress activates the HPA axis, your body is flooded with cortisol. Similarly, this hormonal surge reduces the synthesis of structural components like hyaluronic acid and proteoglycans within the follicle.

Furthermore, high cortisol levels push hair follicles prematurely into the telogen (shedding) phase. This means that managing your internal biology is just as important as choosing the right shampoo for sustained Hair Health.

Natural Solutions: The Power of Antioxidants

Innovation in natural remedies (UiTM, 2025) has found that Avocado Peel Extract is a powerhouse for hair. Rich in phenolic compounds and antioxidants, it offers a stable pH of 5.3—the ideal “sweet spot” for hair fibers.

Additionally, integrating rosemary oil can stimulate microcirculation. These natural approaches work with your hair’s seletividade, providing nutrients without the aggressive chemicals that often trigger hormonal stress.

A Science-Backed Routine

In summary, the secret to vibrant hair is the intersection of proper external care and internal hormonal balance. Understanding your hair’s seletividade is the first step toward a routine that actually works.

Ultimately, Hair Health is a holistic journey. Are you ready to stop guessing and start treating your hair with the scientific precision it deserves?