I assume that you're talking about putting your own urine on your skin?
Well, uric acid is found in a lot of the products that some of us use, so ostensibly, it should help people that respond to the salicylic acid or lactic acid. The big problem is that the quantity varies with your level of activity and the length of time between urination and the amount of liquid you ingest.
There isn't much in urine that will hurt someone. However, the whole point of the kidneys is to eliminate excess acids, so drinking them again pretty well defeats the purpose and makes the kidneys work harder.
This is another one of those techniques where the information available is a combination of truth and absolute BS.
Urine is sterile: true. The bacteria is introduced from the skin and it travels slowly up the urethra. Flushing urine out for the first second or two is sufficient to get a mostly sterile sample, unless you have a UTI.
Urine provides nutrients: Well, yes and no. If there are vitamins and minerals in your urine it is because your body has too much of them already in the system. If you re-ingest them by drinking urine, what do you think the body is going to do with them?
Urine cures disease (flu, AIDS, allergies, snake venom, etc) and increases sperm counts and increases pregnancy: Um. No. It doesn't.
Here's a link on the subject: http://skepdic.com/urine.html
[This message has been edited by Hearsay (edited July 19, 2005).]