In this case, saying the difference is “skin deep” is really saying that it matters a lot. Skin is the largest organ in the human body, and the differences between male and female skin are significant.
It starts with your hormones. The testosterone that helps define maleness causes an increase in skin thickness, with the result that the typical man’s skin is 20-25% thicker than the typical woman’s skin. The cells in male sebaceous glands are more receptive to androgens, which explains why they produce more sebum (i.e. skin oils).
Men also have more natural collagen, and male skin may enjoy better natural hydration. On the minus side, the need to shave and a certain cultural disposition not to bother with skin care counts against males.
We agree with the people at Details.com:
It means that guys are more prone to oily skin, breakouts, blackheads, and clogged pores. In order to achieve balance, men need skin-care products that focus on fighting oil production and unclogging pores.