urea

a metabolic byproduct of the chemical breakdown of PROTEIN and the form in which excess nitrogen is removed from the body in URINE . It is formed in the LIVER and taken in the blood to the KIDNEYS . The amount excreted daily is 30-35 g. Althugh urea is not poisonous in itself, an excess in the BLOOD (uraemia) implies a defective kidney, which will cause an excess of other waste products that may be poisonous.