The pH of healthy skin is about 5.5. It is maintained at that level by skin’s complex regulatory mechanism.
To brush up on what pH means, let’s turn to high school books. pH is a measure of acidic or alkaline nature of a solution. pH less than 7 is called acidic and pH greater than that is called alkaline. pH 7 is considered neutral. Water has a pH of near 7.
Here’s some research that shows why alkaline pH is harmful for the skin.
It can not only corrode skin’s natural protective barrier but also make it open to damage from harsh ingredients like Sodium Lauryl Sulphate (SLS).
It was discovered that when a pH 8 solution was applied to the skin, water loss from the surface of the skin increased. Drier skin.
pH 8 also made skin cells stickier, preventing them from being shed. Clogged pores party.
The paper goes on to say that the alkaline skin care product impaired the skin barrier after repeated application over 5-week period. The skin barrier was disrupted severely by 1% SLS exposure because the surface of the skin was already impaired by alkaline pH and sensitive to external stress. So face washes with irritants like SLS (not normally a major issue) can cause more damage in this case.
So the pH of daily skin care products is very important for skin barrier maintenance.
One of the cult calamine products in India is sold proudly at pH 8. It is even mentioned on the front label of the bottle. I don’t know what science has gone into making of the lotion, and they may have a good reason to keep the pH as 8 (mattify?), but research thinks otherwise.
Forewarned is forearmed. Choose wisely.