As men and women age their testosterone levels diminish. Testosterone is known as the Hormone of Desire . In middle-aged men, low testosterone symptoms (Low T) or Andropause start to appear. Some of the most profound symptoms of low testosterone are - feeling extremely tired all day, unexpected weight gain especially increased belly fat, loss of muscle or muscles getting flabby, low sex drive or a complete lack of desire, softer erections or complete erectile dysfunction, inability to sleep or outright insomnia, memory and hair loss, bursts of anger, social withdrawal and depression.
These secretagogues are distinct from growth hormone releasing hormone (GHRH) in that they share no sequence relation and derive their function through action at a completely different receptor. This receptor was originally called the GH secretagogue receptor, the hormone ghrelin is now considered the receptor's natural endogenous ligand. Therefore, these GH secretagouges act as synthetic ghrelinmimetics. Growth hormone secretagogue receptor is a G protein-coupled receptor that binds ghrelin and plays a role in energy homeostasis and regulation of body weight. Ghrelin is an appetite-regulating factor secreted from peripheral organs that is involved in regulation of energy homoeostasis via binding to the receptor resulting in the secretion of growth hormone by the pituitary gland. A range of selective ligands for the GHSR receptor are now available and are being developed for several clinical applications. GHSR agonists have appetite-stimulating and growth hormone-releasing effects, and are likely to be useful for the treatment of muscle wasting and frailty associated with old-age and degenerative diseases. On the other hand, GHSR antagonists have anorectic effects and are likely to be useful for the treatment of obesity.