I love Zinc Oxide in my sunscreen as it provides the best broad spectrum protection against both UVA and UVB rays. However, besides serving as a great sunscreen ingredient, topical Zinc Oxide is great for wound treatment and even treatment of burns (source). Besides that, the ingredient is known to have minor astringent and antiseptic properties, and hence, is actually great for healing and protecting the skin, and this is why it is a key ingredient in diaper rash creams for babies. Interestingly, I also read that Zinc Oxide is great for treating acne, and some people are actually using diaper rash creams on their faces!
This comes as no surprise since Zinc Oxide’s drying properties is very beneficial in treating diaper rash or oily skin with acne. Zinc Oxide, which is occlusive, can be used to protect the skin from irritations caused by moisture and chafing as it can block irritants from directly contacting the skin, which minimizes the chance of irritation or infection and can help promote healing (source).
High content of ZnO
So diaper creams are really to help babies’ delicate bottoms from developing rashes caused by moisture and a lack of air ventilation through the diaper. And the idea behind using diaper cream for acne is that most diaper rash creams contain a high amount of Zinc Oxide – usually around 10% or more. More importantly, it’s cheap and readily available!
Probably works for those with high oil production
Going by the comments in the acne forum, diaper cream works well for some but not all. However, at the least, it seems to provide some amount of soothing and did not contribute too much issues for most of those who tried it unless the diaper ointment is very greasy. If you want to read some of the reviews, check out the thread here. I think if your acne is caused by an overproduction of oil, it’s no harm giving diaper cream a try. However, if your sunscreen also contains at least 10% of Zinc Oxide, then it should serve as a good reference if this ingredient is helping with your acne.
May not work if your acne is caused by other reasons
Personally, I’ve had good success using Zinc Oxide-based sunscreen when I was having acne. It didn’t aggravate my acne and I suspect it also helped with the healing. However, my acne was not a result of oil production, but rather a manifestation of something wrong with my digestive system then. But diaper cream? Ah, that I’ve never applied on my face. Come to think about it, I didn’t even apply it to my son’s bottom when he was a baby.