No research on most plant extracts, shea has a very low SPF of about 2. IIRC the cinnamates are chemical screens and only block UVB not UVA but both damage the hair, most chemical agents are unstable and break down in UK light.
UV damage of the hair. [Coll Antropol. 2008] - PubMed - NCBI
(link below will download the full text of this review)
Photoaggravation of Hair Aging
[Effects of sunscreening agents and r... [Tidsskr Nor Laegeforen. 1998] - PubMed - NCBI
My other concern with most sunscreens products is using enough to get a decent level of protection, think what a thick layer you are recommended to apply to your face and body, it's not a thin moisturising/ make up/ conditioner spray layer. There are many reasons you never see an SPF on a hair protection product, just very vague hints of what they might do.
Coconut oil as a deep treatment will help reduce protein loss from UV damage because of the affinity for structural proteins, but it's not providing UV protection. For example it likely won't prevent the protective cell membrane complex being destroyed, cuticle damage nor the melanin pigment being broken down which increases porosity. Some antioxidants (is that what you mean by blueberry and coffee extracts?) will protect from free radical damage but not against the other forms of UV damage, like chemical agents they get 'used up' or broken down quickly.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
CO-wash: Inecto coconut
Treatments: Komaza Matani, coconut oil, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume, Inecto argan
Styler: Umberto Giannini jelly, Boots Essentials gel
Experimenting with: going back to basics
Last edited by Firefox7275; 07-23-2013 at 08:43 AM.