I saw some of that lotion that claims to make your hair grow back slower and thinner and wondered how it could possibly deliver the desired effect. So I read the ingredients, and boy, was I suprised when I saw “urea” on that list. Now, correct me if I’m wrong, but I seem to remember learning in A+P that urea is a main ingredient in urine. Completely grossed out, I checked the ingredients of normal lotion and they contain urea too! So, the question is, is urea found anywhere other than urine? Can it be synthesized? Or when I moisturize am I putting horse piss on my legs?
Yes urea can be sythesized in a lab. Urea results from the [http://www.sickkids.on.ca/structuralbiology/images/ureacycle.gif](Urea Cycle,) which IIRC is due to the breakdown or production of certain amino acids. I remember that it is completely reduced (no double bonds) and is holding the maximum number of electrons possible, which serves some purpose which escapes me right now (energy production?). I’m not sure why it’s in your lotion - but possibly it is used as a buffer to control the pH. But in the lab we do use it from time to time (it’s really fun to make b/c when you dissolve it in water it gets really really cold), our primary use is to unfold proteins completely to allow them to be slowly refolded. I dunno, maybe you want proteins on your skin unfolded for some reason?!?! We buy it in 3 kg jugs from Fisher.
Ok I’m great at pasting links…lets try that again.Urea Cycle
In fact, synthesis of urea is generally regarded as a significant event in the development of organic chemistry. It was the first thing known only to be produced naturally by living organisms that was produced in the laboratory using materials from non-living sources. Quite a number of people in the early 19th century subscribed to “vitalism”, which stated that a “vital force” supplied by a living organism was required for the production of such substances. Some background, including a brief note on commercial synthesis: