Testosterone is a steroid hormone produced in the adrenal glands of both sexes and in the testes of males and the ovaries of females. Testosterone is largely responsible for the formation and maintenance of male sex characteristics, including both the larger bone and muscle development seen in males. The testosterone levels in humans are regulated by hormones released from the brain; in males the hypothalamus and pituitary glands in the brain increase testosterone during puberty and male characteristics develop (for example, penile enlargement, facial hair, interest in sex).
Hcg is a drug whose actions are almost the same as those of luteinizing hormone (lh) which is produced by the human pituitary gland. It is manufactured from the urine of pregnant females. Hcg in males, like the lh already produced in the body, stimulates "suitable" testicles to produce the male hormone testosterone. It is not effective in adults whose testicles are damaged, undeveloped, unresponsive or absent. It is given as an intramuscular injection. Hcg has been used for temporary improvement or as a "boost" for certain men with borderline or slightly low testosterone levels in order to improve potency and libido. It is given in various doses for several weeks. Therapy may be repeated if indicated.