Testosterone therapy for men: symptoms, testing, benefits, and risks

Lakewood Ranch Concierge  |  October 1, 2026

Medically reviewed by Leo Kao, MD
Board-certified internal medicine physician

Feeling tired, losing interest in sex, or noticing that workouts don't pay off like they used to? Low testosterone is one possible reason, but it's far from the only one. Here's how low testosterone is diagnosed, what testosterone therapy can and can't do, and how to tell prescription treatment apart from the "testosterone boosters" sold online.

What testosterone does

Testosterone is the main male sex hormone. It supports sex drive and erections, muscle mass and strength, bone density, red blood cell production, energy, and mood. Levels usually peak in early adulthood and drift down gradually with age. For many men that slow decline causes no problems. For others, levels fall low enough to cause symptoms.

Common symptoms of low testosterone

• Low sex drive, or fewer spontaneous or morning erections
• Erectile dysfunction
• Fatigue and low energy
• Loss of muscle mass and strength, or more body fat
• Low mood, irritability, or trouble concentrating
• Thinning bones, which may show up as low bone density on a scan

None of these symptoms is specific to low testosterone. Poor sleep, sleep apnea, depression, thyroid problems, diabetes, medications, and stress can all cause the same complaints. That's why symptoms alone aren't enough for a diagnosis.

How low testosterone is diagnosed

Diagnosis takes both symptoms and blood work. Testosterone levels are highest in the morning and vary from day to day, so major medical guidelines recommend:

• Morning testing. Blood is usually drawn early in the morning, often while fasting.
• At least two low results on separate days before starting treatment.
• Follow-up tests to find the cause, which may include LH and FSH (pituitary hormones), prolactin, a blood count, and, when appropriate for your age, a PSA test.

Many guidelines put the cutoff for low total testosterone at roughly 264 to 300 ng/dL, but the number is interpreted alongside your symptoms, age, and overall health. Free testosterone may also be checked, especially in men who are overweight or older.

Common causes

Low testosterone can come from the testes themselves or from the pituitary gland and brain, which signal the testes. Common contributors include aging, excess weight, type 2 diabetes, untreated sleep apnea, opioid pain medicines, past anabolic steroid use, heavy alcohol use, and certain pituitary or genetic conditions. Finding the cause matters, because treating it can sometimes raise testosterone without hormone therapy.

Lifestyle changes that can help

For some men, especially those with excess weight or poor sleep, lifestyle changes improve testosterone levels and symptoms. Losing weight, strength training, treating sleep apnea, getting enough sleep, and cutting back on alcohol are all worth discussing, whether or not you go on to start therapy.

Testosterone boosters vs. prescription testosterone

"Testosterone booster" supplements sold online and in stores are not the same thing as testosterone therapy. They're dietary supplements, so they don't go through the FDA approval process for safety and effectiveness that prescription drugs do. Good evidence that they meaningfully raise testosterone is lacking, and some products have been found to contain undisclosed or unlisted ingredients.

Prescription testosterone is a regulated medication. In the United States it's a controlled substance, which means it requires an evaluation and ongoing monitoring by a licensed clinician.

Forms of testosterone therapy

Testosterone replacement therapy (TRT) comes in several forms. Each has trade-offs in convenience, cost, and how steady it keeps your levels:

• Injections, given into a muscle or under the skin, typically weekly or every few weeks
• Gels and creams applied to the skin daily
• Patches worn on the skin
• Pellets placed under the skin every few months
• Oral capsules and nasal gel, available in specific FDA-approved forms

Skin gels can transfer to women and children through close contact, which can cause harm. If you use a gel, follow the instructions for covering the area and washing your hands.

Possible benefits

In men with confirmed low testosterone, clinical trials have shown that therapy can improve sex drive and sexual function, and can modestly improve mood, bone density, and anemia. Many men also gain some muscle and lose some body fat. Benefits vary from person to person, and testosterone therapy is not a cure for aging, fatigue, or weight gain on its own.

Risks and side effects

• Higher red blood cell count (erythrocytosis), which can thicken the blood. This is one of the most common reasons for adjusting the dose.
• Reduced fertility. Testosterone therapy lowers sperm production and can cause infertility. If you want children now or in the future, tell your physician before starting, because other approaches may be a better fit.
• Prostate monitoring. Testosterone can raise PSA levels. Men with prostate cancer or certain prostate problems generally shouldn't use it.
• Other effects such as acne, oily skin, breast tenderness or enlargement, fluid retention, smaller testicles, and worsening of untreated sleep apnea.

Heart safety has been studied closely. A large 2023 clinical trial called TRAVERSE found that testosterone therapy did not increase the overall rate of major heart events compared with placebo in men with low testosterone and existing heart disease or risk factors. Some other problems, including an irregular heart rhythm called atrial fibrillation, were more common in the testosterone group. Your physician will weigh your personal heart risk before recommending treatment.

What monitoring looks like

Safe testosterone therapy means regular follow-up, not just a prescription. Monitoring usually includes repeat testosterone levels and a blood count a few months after starting, a PSA check when appropriate, and then periodic labs and symptom reviews, often yearly once things are stable. If treatment isn't improving your symptoms after a reasonable trial, it may be time to stop and look for other causes.

Who should not use testosterone therapy

Testosterone therapy generally isn't recommended for men who have prostate or breast cancer, a very high red blood cell count, or who are actively trying to conceive. It also isn't appropriate for men with normal testosterone levels. Men with a recent heart attack or stroke, severe untreated sleep apnea, or uncontrolled heart failure need careful evaluation first.

Testosterone therapy at Lakewood Ranch Concierge

Hormone evaluation and management for men is part of our membership. Dr. Kao starts with a full evaluation: your symptoms, medical history, medications, and properly timed lab work. If therapy makes sense, he'll go over the options, benefits, and risks with you, then follow your labs and symptoms closely. Because members can reach their physician directly by phone, text, or portal, questions about side effects or dosing don't have to wait for the next appointment.

Medication and outside lab costs may not be included in your membership fee; MD Plan members have bloodwork draw fees waived. Learn about our hormone services, book an appointment, or call or text (941) 237-0129.