Name: Zinc Oxide (or ZnO) that most commonly appears as a white powder.
Good For: acne prone and sensitive skin (a tricky combination!)
Why: Severe deficiency in zinc has been associated with skin conditions such as dermatitis, but as a topical treatment there is little evidence demonstrating zinc as an effective ingredient when applied topically. However, zinc is a soothing and anti-inflammatory ingredient which is a great option for sensitised and acne prone skin (especially if you are using medicated product both orally and/or topically).
How: Dermatology Research and Practice 2014, “Zinc Therapy in Dermatology: A Review”‘ notes, “Topical zinc alone as well as in combination with other agents is effective perhaps because of its anti-inflammatory activity and ability to reduce P. acnes counts by inhibition of P. acnes lipases and free fatty acid level.”
P. acnes here refers propionibacterium acnes (the bacterium linked to the skin condition of acne) and lipases (an enzyme) creates free fatty acids from the sebaceous triglycerides will cause inflammation.