Other factors include changed levels of gonadotropins, hyperandrogenemia and hyperinsulinemia. Combined hormonal contraceptives were developed to prevent ovulation by suppressing the release of gonadotropins. Factors known to increase aromatase activity include age, obesity, insulin, gonadotropins, and alcohol. At low concentration, estrogen inhibits gonadotropins, but high concentration of estrogen stimulates them. Her ovarian pathology was attributed to the elevated levels of gonadotropins. Antigonadotropins are drugs that suppress the GnRH-mediated secretion of gonadotropins from the pituitary gland. Treatment includes administered gonadotropins, which, therefore, work as fertility medication. Frequently the plural is used as the medication is a mixture of gonadotropins. Suppression of gonadotropins in people with anorexia nervosa has been documented. Physicians measure gonadotropins (LH and FSH) to distinguish primary from secondary hypogonadism. There are various preparations of gonadotropins for therapeutic use, mainly as fertility medication. More purified forms of urinary gonadotropins may reduce the LH portion in relation to FSH. In addition to this, the release of these gonadotropins has proven to be dose dependent. For males during puberty, testosterone, along with gonadotropins released by the pituitary gland, stimulates spermatogenesis. Recombinant gonadotropins have to a large degree replaced hMG in fertility treatments.