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.
Testosterone, like many anabolic steroids, was classified as a controlled substance in 1991. Testosterone is administered parenterally in normal and delayed-release (depot) forms. In September 1995, the FDA approved testosterone transdermal patches (Androderm), and many transdermal forms and brands are now available including implants, gels, and topical solutions. A testosterone buccal system, Striant, was FDA-approved in July 2003; Striant is a mucoadhesive product that adheres to the buccal mucosa and provides a controlled and sustained release of testosterone. In May 2014, the FDA approved an intranasal gel formulation of testosterone (Natesto). A transdermal patch (Intrinsa) for hormone replacement in women is under investigation; the daily dosages used in women are much lower than for products used in males. The FDA refused approval for Intrinsa in 2004 stating that more data regarding safety, especially in relation to cardiovascular and breast health, were required.