Smegma ( or Head Cheese)
I have noticed that over the last six months, a yellowy-white substance has been covering my penis underneath my foreskin.
At first I attributed it to hygiene, but seeing as I clean there every day I do not think that this is now the case.
It does wash off but is present again the next day, it also doesn't smell particularly pleasant.
I do not know if it is connected or not but I have in the same time period quite often not been able to maintain an erection or ejaculate.
As I am only 19 I think you will understand that this is naturally not only distressing but highly embarrassing.
I would be very grateful if you could suggest what it could be as I loathe going to my doctor.
The stuff under your foreskin is almost certainly smegma. This is a natural product of the small glands on the penis.
As long as you wash it away each day, there is no hygiene problem. If you don't wash it away, this could lead to irritation of your skin.
None of this has any connection with your problems regarding erection and ejaculation.
At your age, such problems aren't likely to be due to any serious physical cause.
Source: The NetDoctor Medical Team