Yes, it is considered that semen is good for skin.
There is an element called Spermine in sperm which softens the skin and prevents it from wrinkles.
Infact in few western countries their in many cosmetic products which are comprise with sperm as well. Spermine acts as an antioxidant and other elements like zinc, magnesium, calcium, potassium, fructose etc helps in the nourishment of skin.
On a well known news website, I once read a story that their is girl who got allergic to any cosmetic products and she is very conscious towards her looks and skin. So she started to use semen directly as a face pack instead of using it through any other product. She takes it from her friends on regular basis.