Testosterone and Women
Review study shows many benefits and few risks with a commonsense approach to testosterone replacement for women.
Although sex drive or libido in women is multi-faceted, it’s often closely tied to testosterone levels, and a new review study from researchers at Cedars-Sinai in Los Angeles, published in the journal Maturitas, shows that testosterone replacement can bring many health benefits and few risks.
Women with low testosterone often have little or no desire to have sex. Using testosterone replacement therapy may seem like an obvious solution, but some doctors and researchers have been concerned that supplemental testosterone may convert to estrogen and thus create an increased risk of breast and uterine (endometrial) cancers. There has also been concern that testosterone replacement may increase a woman’s risk of heart disease, because men have a higher overall risk for heart disease than women do.
Low testosterone and low libido are often problematic for women who have had their ovaries removed or who have had a hysterectomy. With hysterectomy, even if the ovaries are left intact, their blood supply is compromised and they usually stop functioning within a few years of having the uterus removed. This leaves a woman without any hormone production. In contrast, at menopause, women who still have functional ovaries experience a drop in the production of the hormones estrogen and progesterone, but often keep making testosterone well into their eighties. If a menopausal woman has a bit of fat on her body, it will convert some of the testosterone to estrogen.
Symptoms of Low Testosterone
In addition to low libido, low testosterone in women can also contribute to fatigue, depression and bone loss. Restoring testosterone can improve these symptoms and also help build muscle and burn fat, which helps with weight loss.
Commonsense Use of Testosterone
The bottom line of the Maturitas review, “Safety of Testosterone Use in Women,” is that transdermal (patch or gel) testosterone used in physiologic doses (what the body would naturally make), is safe and may even help prevent heart disease, breast cancer and endometrial cancer. When used with this commonsense approach, it does not tend to convert to estrogen.
I would add that it’s important to use bioidentical testosterone, meaning the same molecule that the body makes. Studies that have used high doses of testosterone, synthetic testosterone (e.g. methyltestosterone) or oral (pill) testosterone show an increased risk of breast cancer and heart disease. It’s also important to only supplement with testosterone if it’s clearly needed. If libido is low but a testosterone test shows normal levels, that’s an indication to look elsewhere for underlying causes, rather than create higher-than-normal levels.
Dr. John Lee recommended that women start with 0.5 mg of transdermal testosterone daily. If side effects such as increased hair growth on the face or arms, hair loss on the head, acne, deepening of the voice or irritability occur, then the dose can go as low as 0.15 mg and still be effective for most women.
Although the Intrinsa testosterone patch made by Proctor & Gamble Pharmaceuticals is available in Europe, the FDA voted it down for U.S. women in 2004, which is unfortunate because the patch is undoubtedly safer than oral testosterone and it comes in a low dose of 0.3 mg. It’s ironic that the FDA is so willing to approve dangerous drugs such as Celebrex and Avandia, but not willing to approve a low dose bioidentical hormone patch. I’m sure the inside politics of this poor decision by the FDA would make good reading.
How to Find Safe Testosterone
The only FDA-approved testosterone for women available in the U.S. is Estratest, which contains esterified estrogens and synthetic methyltestosterone. Until recently it was only available in high doses. This is the primary drug in the U.S. that has given testosterone supplementation in women a bad name, and for good reason. The other bioidentical testosterone available in the U.S. is Androgel, but it's a gel made for men which can make it challenging to use a small enough dose.
The only way for a woman to get bioidentical testosterone in the appropriate dose in the U.S. is to have a doctor’s prescription to have it made at a compounding pharmacy, preferably as a gel or cream. Some bioidentical hormone doctors are using testosterone drops, or pellets injected into the arm, but drops can have local effects (e.g. facial hair) and pellets can’t be removed so if the dose is too high you’re stuck with it for at least three months.
Testosterone levels are most accurately tested in a blood spot test.
Davis SR, Moreau M, Kroll R et al, “Testosterone for low libido in postmenopausal women not taking estrogen,” N Eng J Med 2008 Nov 6;359(19):2005-17.
Ness RB, Albano JD, McTiernan A, Cauley JA, “Influence of estrogen plus testosterone supplementation on breast cancer,” Arch Intern Med 2009 Jan 12;169(1):41-6.
Shufelt CL, Braunstein GD, “Safety of testosterone use in women,” Maturitas 2009 May 20;63(1):63-6.