Shea has a light sunscreen factor. When zinc oxide is added, an SPF of about 20% is achieved. I tested it many times in the big sun to rejoice in its effectiveness.
In addition our shea, which softens the skin, is enhanced with vanillin, shea butter, vanilla oleoresin, CO2 (regenerative) sea buckthorn oil and essential oils of sweet orange, petit grain and neroli that help the skin absorb sunlight and a hint of vegetable glycerin that gives it a sublime texture.
Ingredients: butyrospermum parkii butter (shea butter), butyrospermum parkii shea oil (shea oil), vanillin, hippophae rhamnoides (CO2 buckthorn), citrus sinensis (sweet orange HE), citrus aurantium (small grain HE), citrus aurantium amara ( HE neroli), vegetable glycerin
We attach to your vanilla shea 50 g, a bag with the portion of zinc oxide to add. In 5 minutes, your preparation is ready: just heat the contents of the shea bath in a bain-marie (1 minute and it's done), remove the fire and add the portion of zinc oxide and then put in the freezer an hour to freeze again. There you go. Be sure to mix the two ingredients well so that everything is homogeneous.
How often should shea be applied? It always depends on the exposure time. We must adjust if we are in full sun all day, we bathe, we put more often.
See here on video, how to make sun protection.
* Our vanilla shea with zinc oxide contains 15% zinc oxide (9 (7.5) grams of zinc oxide for 50 grams of shea). We therefore estimate its protection factor around 20.
Reference sources for zinc oxide sunscreens:
DermaQuest Announces SPF 30 with 18% Zinc Oxide: http://www.ewg.org/2015sunscreen/about-the-sunscreens/620839/DermaQuest_ZinClear%2C_Tinted%2C_SPF_30/
Dr. Mercola Sunscreen discusses an SPF of 15 with 9.5% zinc oxide: http://www.ewg.org/2015sunscreen/about-the-sunscreens/620108/Dr._Mercola_Sunscreen%2C_SPF_15/