Built on evidence, not guesswork

Textured hair has a distinctive structure: a curved, asymmetric cross-section and a different arrangement of keratin and protective lipids compared with straight hair. That structure makes it more vulnerable to mechanical and chemical stress, and to environmental factors like UV exposure, heat and styling.

Textured hair also makes up a substantial share of the world's population, and much of that population lives in regions with high UV indices. Despite this, hair care research and formulation has historically centred on straight hair, leaving a gap in products designed around what textured hair actually needs.

We evaluated the UV-absorbing and antioxidant properties of mangiferin, ferulic acid and naringin, both individually and blended into the finished conditioner. Hair samples were pre-treated with the conditioner, exposed to standardised UV radiation, and compared against untreated hair.

Damage was assessed using dye-penetration testing, light and fluorescence microscopy, ATR-FTIR spectroscopy and scanning electron microscopy, looking at changes in fibre thickness, colour and keratin structure.

Mangiferin showed the strongest UV-absorbing properties across UVA, UVB and UVC, with ferulic acid and naringin covering the UVB and UVC range. All three showed strong antioxidant activity individually, and the blended conditioner's absorbance covered the full UV range.

UV exposure reduced fibre thickness and caused visible bleaching, with curly hair affected more than straight hair. Hair pre-treated with the conditioner kept more of its thickness and natural colour, and showed less dye penetration, indicating better-preserved structural integrity.

At a molecular level, UV exposure disrupted keratin bonds, particularly in curly hair. Pre-treatment with the conditioner helped preserve the keratin structure, an effect confirmed through spectroscopy and electron microscopy.

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