Loss of libido is a decrease in the human drive to be sexual. It is sometimes considered to be different from Sexual Desire, which is the ability to feel and direct that drive.

Loss of libido may follow physical illness, stress or fatigue. The continued high use of alcohol or marijuana will reduce the production of male hormones. Loss of Libido may reflect the normal periodic changes in hormone levels, and it may decline gradually in mid-life with the onset of the male menopause (andropause).

Treatment
After investigation into possible physical causes, a simple blood test that measures all hormone levels will indicate whether replacement therapy is needed. Women usually require oestrogens with progesterone while men require testosterone. Both sexes may benefit from the hormone DHEA (Dehydroepiandrosterone) from which sex hormones are made. A check should be made every few months to review hormone levels in the blood and to make sure there are no unwanted side-effects.