TUESDAY, June 27 (HealthDay News) — Three new studies suggest that testosterone can be of real help, and potential harm, to women.

Women do have natural, low levels of these “male hormones,” and improving deficiencies by using a testosterone patch can boost mood and sexual health, two studies found.

But a third study found that high levels of testosterone can also triple heart risks for older women.

Taken together, the findings underline the fact that “we don’t know what really is considered to be a normal or beneficial testosterone level at this point,” said Dr. Anne R. Cappola, an assistant professor of medicine and epidemiology at the University of Pennsylvania, and lead researcher on the heart-risk study.

The studies were presented Monday at the annual meeting of the Endocrine Society, in Boston.

Testosterone is usually thought of as a male hormone, but women have it, too. For women with androgen (male hormone) deficiency, supplemental testosterone can improve mood, sexual function and quality of life, researchers from Massachusetts General Hospital in Boston reported.

“We thought of testosterone as being a male hormone and estrogen a female hormone,” said lead researcher Dr. Karen Miller, an endocrinologist and assistant professor of medicine at Harvard Medical School in Boston. “But we are learning more and more that things are not as simple as that,” she said.

In their study, Miller’s team randomly assigned 51 premenopausal women with below-normal or undetectable levels of testosterone to either a placebo or Proctor & Gamble’s testosterone patch, Intrinsa, which has not yet received U.S. Food and Drug Administration approval for use by American women.

During companies the one-year trial, women on the testosterone patch showed improvements in mood, sexual function and quality of life. There was, however, no change in cognitive function, they reported.

“Bringing testosterone levels up to normal, when there are low levels due to a pituitary problem, improves mood and sexual function. There were also improvements in quality of life, including energy level,” Miller said.

She cautioned that the study did not deal with women with normal testosterone levels. “Our concern is that supplemental testosterone in women with normal levels would have side effects, like unwanted facial and body hair,” she said.

The student loan calculator data are very preliminary, Miller added. “There is no Food and Drug Administration testosterone patch approved for women,” she said.

In a second study — this time by researchers at Monash University in Melbourne, Australia — investigators gave either the 150 gram/day or 300 gram/day versions of the Intrinsa patch, or a placebo, twice a week to 771 postmenopausal women.

Six seo tips months into the study, women on the 300 gram/day patch reported “significantly improved” levels of sexual activity, desire, and other markers of sexual function, as well as lowered anxiety, compared with women taking placebo. Women on the lower-dose (150 grams/day) patch saw only minimal improvements in sexual function, the Australian team reported.

The researchers noted that women on higher-dose Intrinsa did experience “an increase of the frequency of unwanted hair,” although this side effect was rated as “mild to moderate in severity.” The study was funded by Proctor & Gamble.

Last December, the FDA voted against the approval of Intrinsa for women with low libido, citing insufficient long-term safety data. Thus far, the only such remedies available to women with low libido are off-label, including Estratest (estrogen and methyltestosterone), currently on the market for relief of menopausal symptoms, and some other products that are specifically made for men.

One expert said Miller’s study is important, but cause-and-effect re