Hair and scalp have different needs
UV exposure can affect the surface and colour of hair fibres, leaving lengths rougher, duller and more fragile. Your scalp is skin and can sunburn. A product that conditions your hair is therefore not automatically sunscreen for your scalp.
1. Start with shade and a wide-brimmed hat
Seek shade when the sun is strong and choose a wide-brimmed hat in tightly woven fabric, ideally with a UPF label. Open-weave straw hats give uneven coverage. Tuck long lengths loosely under the hat; a braid or bun alone does not protect scalp skin from UV.
2. Apply sunscreen to exposed scalp skin
Protect your parting, hairline and thinning areas where skin shows. Choose sunscreen intended for skin with UVA and UVB protection, at least SPF 30 and water resistance when swimming. Apply directly to skin as directed. Reapply about every two hours outdoors and after swimming, sweating or towel drying. Hats and shade still matter.
3. Choose hair products for their documented purpose
If you need UV protection for your hair, look for a product explicitly labelled for that purpose. Follow the product's directions for amount and reapplication. Protection from the heat of hairdryers and straighteners does not automatically mean UV protection. SPF describes skin protection; ordinary hairspray, conditioner and hair oil do not replace scalp sunscreen.
4. Take extra care with coloured and bleached hair
Sun can change both natural and cosmetic pigments. Cover the lengths and use conditioner and, if needed, a mask according to your hair's needs and the instructions. Colour care can improve appearance but cannot guarantee unchanged colour. Limit intense heat styling, especially if hair is already fragile.
5. Before and after swimming
Consider rinsing hair with fresh water before swimming and wearing a swim cap. Rinse out salt or chlorine afterwards and wash as needed with shampoo suited to your scalp and hair. Swimming can remove applied products; follow their directions again. A swim cap or leave-in is not automatically UV protection.
6. Condition your lengths after a day outdoors
Work conditioner through the lengths and gently detangle from the ends. A leave-in serum such as Repair & Shine can be used for softness, shine and frizz control as directed. Conditioning improves feel and appearance but does not undo UV damage. A product cannot permanently repair split ends.
Questions about sun protection for hair
Can coconut, argan or rosemary oil replace sunscreen?
No. Ordinary hair oils do not have a documented sun protection factor and should not replace sunscreen, a hat or shade. Use them only as hair care when needed.
Should scalp sunscreen be applied to the hair?
Sunscreen needs to cover exposed skin according to its instructions. A layer on the hair fibres does not ensure coverage of your parting or thinning areas.
Read also
Sources for the skin sun-protection advice: American Academy of Dermatology.