Not so fast. A low testosterone level by itself doesn't need treatment. Testosterone replacement therapy can have side effects, and the long-term risks and benefits aren't known. Only men with symptoms of low testosterone and blood levels that confirm this as the cause of symptoms should consider testosterone replacement. Talking with your doctor is the only way to know if testosterone therapy is right for you.
Subtle Symptoms of Low Testosterone
The symptoms of low testosterone are sometimes obvious, but they also can be subtle. Testosterone levels decline naturally in men as they age over decades. But certain conditions can also lead to an abnormally low level. Symptoms of low testosterone include:
- Low sex drive (libido)
- Erectile dysfunction
- Fatigue and poor energy level
- Decreased muscle mass
- Body and facial hair loss
- Difficulty concentrating
- Low sense of well-being
If men have symptoms of low testosterone and tests show they have an abnormally low testosterone level, a doctor may suggest treatment. For millions of men who have low testosterone levels but no symptoms, no treatment is currently recommended. It has also not been approved for treating men with low levels because of aging.
Forms of Testosterone Supplements
Testosterone replacement therapy is available in several forms. All can improve testosterone levels:
- Skin patch (transdermal): Androderm is a skin patch worn on the arm or upper body. It's applied once a day.
- Gels: AndroGel and Testim come in packets of clear testosterone gel. Testosterone is absorbed directly through the skin when you apply the gel once a day. AndroGel, Axiron, and Fortesta also come in a pump that delivers the amount of testosterone prescribed by your doctor. Natesto is a gel applied inside the nose.
- Mouth patch:Striant is a tablet that sticks to the upper gums above the incisor, the tooth just to the right or left of the two front teeth. Applied twice a day, it continuously releases testosterone into the blood through the oral tissues.
- Injections and implants: Testosterone can also be injected directly into the muscles, or implanted as pellets in the soft tissues. Your body slowly absorbs the testosterone into the bloodstream.
Why not a simple testosterone pill? Oral testosterone is available. However, some experts believe oral testosterone can have negative effects on the liver. Using other methods, such as skin patches, gels, orally disintegrating tablets, or injections, bypasses the liver and gets testosterone into the blood directly.
Benefits of Testosterone Therapy
What can you expect from testosterone treatment? It's impossible to predict, because every man is different. Many men report improvement in energy level, sex drive, and quality of erections. Testosterone also increases bone density, muscle mass, and insulin sensitivity in some men.
Men also often report an improvement in mood from testosterone replacement. Whether these effects are barely noticeable, or a major boost, is highly individualized.
Karen Herbst, MD, PhD, an endocrinologist at University of California-San Diego, specializes in testosterone deficiency. She estimates about one in 10 men are "ecstatic" about their response to testosterone therapy, while about the same number "don't notice much." The majority have generally positive, but varying responses to testosterone replacement.
Risks of Testosterone Therapy
However, there is also evidence of a possible increased risk of heart attack or stroke associated with testosterone use. Experts emphasize that the benefits and risks of long-term testosterone therapy are unknown, because large clinical trials haven't yet been done.
There are a few health conditions that experts believe testosterone therapy can worsen:
- Benign prostatic hypertrophy (BPH): The prostate grows naturally under the stimulation of testosterone. For many men, their prostates grow larger as they age, squeezing the tube carrying urine (urethra). The result is difficulty urinating. This condition, benign prostatic hypertrophy, can be made worse by testosterone therapy.
- Prostate cancer: Testosterone can stimulate prostate cancer to grow. Most experts recommend screening for prostate cancer before starting testosterone replacement. Men with prostate cancer or elevated prostate specific antigen (PSA) should probably avoid testosterone treatment.
- Sleep apnea: This condition can be worsened by testosterone replacement. It may be difficult for men to detect this themselves, but their sleeping partner can often tell. A sleep study (polysomnography) may be needed to make the diagnosis.
- Blood clots: The FDA requires that testosterone replacement products carry a warning about the risk of blood clots in veins. This could increase the risk of deep vein thrombosis and pulmonary embolism , a potentially life threatening clot that occurs in the lungs. Products already carried a warning about the risk of blood clots due to polycythemia, an abnormal rise in the number of red blood cells that sometimes occurs with testosterone treatment. Now the warning is more general to include men who don't have polycythemia.
- Congestive heart failure: Men with severe congestive heart failure should usually not take testosterone replacement, as it can worsen the condition.
It will be years before large clinical trials bring any answers on the long-term benefits and risks of testosterone therapy. As with any medicine, the decision on whether the possible benefits outweigh any risks is up to you and your doctor.
Testosterone Replacement vs. Performance-Enhancing Steroids
Isn't taking testosterone replacement basically the same as taking steroids, like athletes that "dope"? It's true that anabolic steroids used by some bodybuilders and athletes contain testosterone or chemicals that act like testosterone.
The difference is that doses used in testosterone replacement only achieve physiologic (natural) levels of hormone in the blood. The testosterone forms some athletes use illegally are in much higher doses, and often combined ("stacked") with other substances that boost the overall muscle-building (anabolic) effect.