3 forming a mathematical complement. sine and cosine are complementary functions. 4 (Maths, logic) (of a pair of sets, functions, etc.) mutually exclusive and exhaustive, each being the complement of the other. 5 (of genes) producing an effect in association with other genes. 6 involving or using the treatments and techniques of complementary medicine.
We know that fertility does decline. We know that after the age of 30, there is a drop in testosterone of 1 percent a year. Testosterone is the energy, the hormone that you need to make good-quality sperm.
email. MNT featured. For many men, testosterone levels drop as they get older, but new research presented at a conference this week suggests this is not necessarily a consequence of age itself, but more to do with behavior, such as smoking, and changes in health, such as obesity and depression.