It’s important to note that the normal ranges for testosterone levels can vary based on the type of blood test done and the laboratory where it is done. As testosterone in your blood increases, it suppresses the production of gonadotropin-releasing hormone, which helps maintain normal levels of testosterone. Low levels of testosterone in women are best treated by addressing any underlying medical or mental health issues, not by taking testosterone supplements made for men. But in some cases, treating underlying medical conditions doesn’t normalize production of these hormones. If your testosterone levels are abnormal, you may have an underlying medical condition causing your levels to be thrown off. As men and women age, their bodies produce less testosterone, but it continues to play a role in maintaining health and libido for both. In women, normal testosterone levels range from 15 to 70 nanograms per deciliter (ng/dL) of blood. Testosterone therapy may make sense for women who have low testosterone levels and symptoms that might be due to testosterone deficiency. (Testosterone levels under 20 ng/dL in women 50 and older are typically considered low.) It’s also important to check sex hormone binding globulin, or SHBG, because if it’s high, "any exogenous testosterone we give someone is just going to be bound up," she says. Whether as a treatment for female-to-male gender-affirming hormone therapy or for testosterone deficiency, there are numerous mental and physical health benefits. As men age, testosterone levels naturally decline - but stress, lifestyle, and certain health conditions can cause levels to drop faster than expected. "Once they’re in your body, you can't alter or adjust the dose or how long you're exposed to it," Kurtzer says. That can be especially true for those receiving pellets, which typically contain higher doses than other forms of testosterone. "My boss pulled me aside and was like, ‘April, you can't talk like that to me.’" She ended up stopping treatment. However, the long-term safety and effects of testosterone therapy to increase libido in women isn’t well understood. However, testosterone levels also naturally decrease as we age, so there isn’t always an underlying concern. Higher testosterone levels in women may indicate a tumor on the ovaries or adrenal glands. Testosterone is the primary male sex hormone, though it also plays roles in women. Low testosterone levels can contribute to fatigue, reduced muscle mass, lower libido, mood changes, and decreased energy in men. Beginning around age 30 to 40, testosterone levels may start to slowly decrease. Feeling unusually tired (fatigue), even after enough sleep, is a common symptom of low testosterone4. Think of it as one of the body’s main 'performance regulators.' If you are concerned about low-T symptoms, or if you've tried therapies that didn't work, talk with your primary care doctor or urologist. In rare cases when neither therapy works, we can consider increasing the FSH level as well with injections of the FSH substitute hMG.
