Zinc oxide is a powdered mineral that sits on top of the skin, scattering, reflecting, and absorbing UVA & UVB rays. Although zinc oxide is the safest and most effective active sunscreen ingredient, the best protection from the sun is to seek shade and cover up with clothes and a hat.
Story at-a-glance 1  -. With immediate and antibiotic-free treatment, strep throat can improve in two to five days, up to a week. 2  Immediate treatment of strep throat is very crucial not just for quick recovery, but because an untreated case of strep throat can lead to further complications.
Updated February 14, 2017. Strep throat is contagious for 2 to 5 days before you even start to experience symptoms. During this time, you may unknowingly share your germs with someone else. The duration of being contagious is dependent upon when you start taking antibiotics.