Testosterone replacement therapy is a hormone replacement therapy for men to treat hypogonadism or low testosterone levels. Men typically use testosterone therapy for symptoms such as low libido, depressed mood and decreased energy levels.
What Is Testosterone Therapy?
The U.S. Food and Drug Administration (FDA) approved testosterone therapy for men who want to address hypogonadism and low testosterone. Hypogonadism is when the body does not produce enough testosterone, and it occurs in 19% of men in their 60s. The rates increase for men in their 70s (28%) and 80s (49%).
The popularity of testosterone therapy rose from 2000 to 2013, when a multitude of the hormone products came to market. More than 2 million Americans took testosterone products, including older men using it to improve libido.
The FDA later warned men about the dangerous side effects of these products, including cardiac events. Although testosterone therapy remains popular, concerns about side effects may ultimately reduce demand.
How Does Hormone Therapy Work?
Your body has androgen receptors in tissues throughout your body that help your body use hormones for different important functions. These receptors in tissues from reproductive organs to the brain all respond to increased testosterone taken orally, through injections or through the skin in patches, gels and creams.
When you start testosterone therapy, the hormone produces increased muscle mass, more body hair and increased sex drive. Some effects of TRT can be felt within weeks, while others build over the course of months.
Types of Testosterone Products
Testosterone, as a Schedule III drug, is available only with a prescription. Although there are many supplements claiming to boost testosterone, these over-the-counter products do not contain testosterone and lack any peer reviewed evidence of effectiveness.
Gels (Androgel and Testim)
Testosterone gel is a prescription medication applied directly to a man’s skin. It can be applied to the shoulders, upper arms and abdomen, depending on the brand.
Testosterone gel can unintentionally transfer from your body to another’s with skin to skin contact. This can potentially lead to serious health reactions for the other person.
To avoid this type of gel transfer, apply it to clean, dry and intact skin that clothing can cover. Wash your hands right away with soap and water after applying. Once the gel has dried, cover the area with clothing and keep it covered until you have washed it well or showered.
First approved in 1979, Depo-testosterone is one of the older drugs of its kind on the market. It’s a liquid designed for injection deep into the gluteal muscle.
The active ingredient, testosterone cypionate, is a powder mixed with other ingredients to make a solution. The drug is available in two strengths, 100 mg and 200 mg.
Testosterone transdermal patches, including Androderm, come as patches to apply to the skin. Patches work best when applied around the same time each night and are left in place for 24 hours. Testosterone patches are worn at all times until replaced with new patches.
Androderm patches should be changed every 24 hours. The old patch should be removed before applying the new one. You should apply the patches to different spots each night and wait at least seven days before re-using a spot.
Capsules (Methyltestosterone and Android)
Combined estrogen-methyltestosterone capsules have been discontinued. They were used to treat delayed puberty in men and boys and breast cancer in women.
Methyltestosterone, an artificial form of testosterone, alone is still available – in capsule and tablet form. It can affect bone growth in boys who are treated for delayed puberty.
Testosterone boosters are not testosterone therapeutics. These are supplements with very little evidence to support their use.
Despite insufficient scientific data to support claims, manufacturers have suggested their products increase muscle mass, strength and sex drive in men. Among the most popular testosterone boosters are products containing Tribulus terrestris, DHEA, zinc and d-aspartic acid.
These ingredients have been associated with several side effects, including aggressiveness, breast enlargement, cholesterol changes, prostate problems and an increased risk of cardiovascular disease.
Why Men Use Testosterone Therapy
Men opt for testosterone replacement therapy to counteract a condition of low testosterone, often referred to as “Low T.” For many men, levels of this hormone decrease with age, leading to erectile dysfunction, low libido, loss of body mass and muscle, anemia and depressive moods.
Men turn to testosterone therapy to increase muscle tone, sexual desire and sexual performance, resulting increased confidence as they grow older.
Treating Low T
The FDA approved testosterone as replacement therapy only for men who have low testosterone levels from disorders that cause hypogonadism. Testosterone levels in men usually decline after age 30.
Other causes of Low T include an injury to the testicles, cancer treatments, chronic diseases and stress. Lack of this key sex hormone can also cause health issues, including osteoporosis, loss of muscle mass and strength (sarcopenia) and psychological symptoms. Doctors prescribe testosterone drugs to treat these symptoms.
Remedying Erectile Dysfunction
As men age, erectile dysfunction (ED), the inability to get or maintain an erection, is common. Before Pfizer released Viagra in 1998 as a medication for ED, doctors often turned to testosterone as a treatment.
However, only about 5% of men experience ED because of Low T. Low testosterone levels can contribute to ED but are more likely to reduce sexual desire than cause the condition.
Enhancing Physical Performance
Testosterone therapy can enhance athletic and physical performance. Athletes use it to boost strength and stamina, but it can also help men with chronic fatigue syndrome or fibromyalgia.
The National Football League (NFL) in 2011 banned players’ use of testosterone except for extraordinary health circumstances because of its ability to increase strength and muscle mass.
Benefits of Testosterone Therapy
For many men, the biggest benefit of testosterone therapy is an improved sex drive. But there are other benefits related to muscle growth and body mass, which high-performance athletes and physical trainers acknowledge.
- Increased libido: Testosterone enhances sex drive, making it especially popular among for men older than 50.
- Boosted energy level: Testosterone levels decline with age, leading to fatigue and exhaustion. Testosterone therapy can boost energy levels.
- Increased muscle building: Testosterone increases muscle mass beyond the results possible from a typical workout regimen alone.
- Better memory: Higher testosterone levels have been associated with improved recall.
While some men report experiencing benefits shortly after beginning treatment, most studies indicate results take weeks or months.
Risks of Testosterone Therapy
Because it involves a potent hormone, testosterone therapy carries a handful of risk factors. Some are common while others are rare. Not all are serious, but anyone who undergoes therapy should be aware of the potential life-changing side effects.
- Worsening sleep apnea: Some research suggests testosterone therapy can intensify sleep apnea, a disorder in which you temporarily stop breathing while asleep.
- Acne and skin reactions: Some men experience skin breakouts and severe acne after beginning a cycle of testosterone. You can treat these side effects with anti-inflammatory medications or changing the dosage.
- Noncancerous prostate growth: Testosterone therapy has long been linked with enlarged prostates in men, which often affects the ability to empty the bladder successfully. In rare instances, benign prostate growths can lead to more serious issues such as prostate cancer.
- Polycythemia: This is a condition of having too many red blood cells, thickening the blood. If chronic, the condition is called polycythemia vera, or leukemia.
Recent studies had mixed findings about links between testosterone replacement therapy and increased risks of obesity, diabetes and metabolic syndrome. Research linking it to an increased risk of cardiac events is still a source of debate, and studies continue to examine long-term cardiovascular risks.
Heart Attacks and Cardiovascular Side Effects
Multiple research studies tie high concentrations of testosterone products to an increase in heart failure events, though there is some debate. Some scientists suspect it may be related to elevated blood pressure.
The FDA in 2014 warned against using testosterone therapy for age-related low T, noting the therapy requires more study. An ongoing testosterone replacement therapy trial related to the testosterone and heart-related side effects is scheduled to conclude in late 2022.
Dangers to Women and Children
The FDA approved testosterone products only for men with low testosterone levels. Children should never be exposed to testosterone products because they can cause premature puberty and health problems such as liver damage.
Women can inadvertently and dangerously raise their testosterone through skin to skin contact with a man undergoing treatment. Most exposures happen with the gel and cream forms of TRT. When women are exposed to testosterone they may also experience increased hair growth on her face and body, a deeper voice and increased muscle mass.
How can we improve this page?
Thank You for Your Feedback
We appreciate your feedback. One of our content team members will be in touch with you soon.
We appreciate your feedback. One of our content team members will be in touch with you soon.
Calling this number connects you with a Drugwatch representative. We will direct you to one of our trusted legal partners for a free case review.
Drugwatch's trusted legal partners support the organization's mission to keep people safe from dangerous drugs and medical devices. For more information, visit our partners page.