Testosterone Transdermal gel: In transdermal testosterone, the hormone is released slowly through the skin to deliver a constant level in the blood, again not a routine pattern, but convenient.

Compounding pharmacists can offer many options to provide for different blood level profiles and convenience of administration. Topical testosterone can be applied using different vehicles to more closely mimic the normal adult physiological pattern, i.e., apply early in the morning where it should be absorbed over a period of a few hours.

Testosterone, the most common agent used in male hormone replacement therapy, occurs as white or slightly creamy white crystals or crystalline powder that is odorless and stable in air.  It is practically insoluble in water, soluble 1 g in 5 mL of ethanol, 2 mL of chloroform and 100 mL of ether and is soluble in vegetable oils, melts between 153 and 157ºC., and is subject to photodegradation in the presence of light. Testosterone is not very bioavailable when given as an oral-swallow preparation, but is absorbed when administered bucally and sublingually.  The different esters of testosterone are hydrolyzed to free testosterone and, subsequently, are metabolized in the same way as testosterone itself .

Treatment
The therapeutic goal is enable the adult man to maintain or improve strength to function better and more consistently.  Many physicians hesitate to use testosterone supplementation as it is new, they have heard stories (sometimes related to synthetic androgen supplementation), and they are unsure of the results as it takes quite some time for them to become evident.  There is no evidence that exogenous testosterone stimulates the development of prostate carcinoma; there has been no relationship established between endogenous testosterone and BPH.  However, a contraindication to androgen replacement therapy is the presence of prostate cancer.

Who qualifies for testosterone therapy programs.
The decision to use HRT is an individual one, based on the individual's particular risks. The goals of natural HRT are to:

Natural testosterone replacement is central to the treatment of all aspects of "male menopause". Testosterone supplementation has resulted in decreasing body fat mass from 6.4% to 1.4% and increases in lean mass from 3.2% to 5%.  Increases in strength (grip strength) also are reported.

Total cholesterol and low density lipoproteins tend to significantly decrease with testosterone administration. Three steroids of importance in the male reproductive function are testosterone, dihydrotestosterone and estradiol.  By far the greatest percentage of testosterone (over 95%) is secreted by the testicular Leydig cells.  The dihydrotestosterone and estradiol are derived from both the direct secretion from the testes (20%) and also from conversion in peripheral tissues on androgen and estrogen precursors secreted by both the testes and adrenal glands (80%).

Hormone preparations that have been used include testosterone, testosterone propionate, testosterone enanthate, testosterone cypionate, fluoxymestrone, methyltestosterone (methyltestosterone is toxic to the liver and heart and may have clouded the benefits of testosterone replacement therapy), oxandrolone, progesterone, and estradiol.  Commercial testosterone products have been administered either by injection, implants/pellets, orally or as transdermal patches.

Possible side effects
The goal of testosterone replacement therapy is to achieve normal to optimal levels of testosterone. For most patients, testosterone replacement therapy is safe. Possible side effects, however, include water retention, male pattern baldness, gynecomastia (enlarged breasts). The oral forms are also associated with liver problems. The use of large doses of testosterone (in bodybuilding, for example) increases the risks of side effects.

Decreased normal testosterone production, prolonged or excessive testosterone therapy prompts the pituitary gland to stop producing the hormone gonadotropin. This in turn, surpresses normal testosterone and sperm production, accompanied by shrinkage of the testicles and frequent or continuing (and sometimes painful) erections. Because of this, testosterone replacement therapy is usually prescribed in cycles. After a 2- or 3-month period, the patient takes a different drug (such as HCG) that stimulates the testicles to begin production of natural testosterone again.