TRT Side Effects: 7 Risks Men Should Understand

Testosterone replacement therapy can be helpful for men who have symptoms and consistently low testosterone levels confirmed through appropriate testing. However, it is still a prescription medical treatment. Understanding possible TRT side effects allows patients to ask better questions, recognize changes and follow their treatment plan responsibly.

The goal of medically supervised TRT is not to push testosterone as high as possible. Treatment should aim to address a confirmed deficiency while keeping hormone levels and other health markers within an appropriate range.

Here are seven potential side effects men should understand before beginning testosterone therapy.

1. Increased Red Blood Cell Production

Testosterone can stimulate the production of red blood cells. This may be beneficial for someone with certain forms of anemia, but an excessive increase can cause the blood to become more concentrated.

Healthcare providers monitor this through hemoglobin and hematocrit measurements. If hematocrit rises too much, a provider may adjust the dose, pause treatment or recommend another appropriate step based on the patient’s health.

Possible warning signs can include:

• Headaches
• Facial redness
• Dizziness
• Unusual fatigue
• Shortness of breath

These symptoms have many possible causes, so laboratory testing is necessary. The American Urological Association recommends measuring hemoglobin and hematocrit before testosterone treatment and informing patients about the risk of an excessive increase in red blood cells.

2. Acne and Oily Skin

Acne is one of the more visible TRT side effects. Testosterone can increase activity in the skin’s oil-producing glands, which may contribute to oily skin or breakouts.

This does not happen to everyone. The response may depend on a person’s skin, hormone levels, dosage and sensitivity to hormonal changes.

Patients should tell their provider if acne becomes painful, widespread or difficult to control. Changing a treatment schedule without medical guidance can create unnecessary hormone fluctuations. A provider can review laboratory results and determine whether the current plan remains suitable.

3. Changes in Blood Pressure and Fluid Retention

Some testosterone products can increase blood pressure. Fluid retention may also cause swelling around the ankles, feet or lower legs in certain patients.

In February 2025, the U.S. Food and Drug Administration required testosterone-product labeling to include warnings about increased blood pressure. This makes blood-pressure monitoring an important part of responsible TRT care.

Men should tell their provider about a history of hypertension, heart disease, kidney disease or unexplained swelling before beginning treatment.

Seek immediate medical help for chest pain, severe shortness of breath, fainting or sudden weakness. These symptoms should never be treated as a routine adjustment to hormone therapy.

4. Reduced Sperm Production and Fertility

Testosterone taken from an outside source can signal the body to reduce its own testosterone production. This can lower sperm production and affect fertility.

Men who want children now or in the future should discuss this before starting treatment. The Endocrine Society’s testosterone-treatment guideline recommends against beginning testosterone therapy in men who are planning fertility in the near term.

Fertility goals should be part of the initial consultation, even when having children is only a future possibility. Depending on the individual situation, a qualified provider may discuss testing or other medically appropriate options.

Never add fertility medication or change a testosterone dose without professional guidance.

5. Breast Tenderness or Enlargement

Some testosterone is naturally converted into estrogen through a process called aromatization. If the balance between these hormones changes, a patient may notice breast tenderness, sensitivity or enlargement.

Weight, body composition, dosage and individual hormone metabolism can influence this response. The presence of breast tenderness does not automatically mean that estrogen must be blocked.

Unnecessary estrogen suppression can create its own problems. A provider should review symptoms and relevant laboratory results before deciding whether any change is needed.

A new breast lump, nipple discharge or persistent one-sided pain requires medical evaluation rather than an assumption that TRT is responsible.

6. Sleep Changes or Worsening Sleep Apnea

Some men report changes in sleep after beginning testosterone therapy. Testosterone may also worsen untreated obstructive sleep apnea in susceptible individuals.

Possible signs of sleep apnea include:

• Loud, persistent snoring
• Pauses in breathing during sleep
• Waking up gasping
• Morning headaches
• Daytime sleepiness despite spending enough time in bed

The Endocrine Society lists untreated severe obstructive sleep apnea among the conditions in which testosterone therapy should generally not be started.

Sleep quality should be discussed during the initial evaluation and follow-up visits. Treating possible sleep apnea can improve overall health independently of testosterone levels.

7. Mood, Libido or Energy Changes

TRT is often discussed in connection with mood, sexual function and energy, but the response is not identical for every patient. Some men may experience irritability, restlessness, difficulty sleeping or noticeable mood changes.

These problems may be more likely when hormone levels fluctuate or treatment produces levels outside the desired range. Mood symptoms can also have causes unrelated to testosterone.

Tell your provider about significant emotional changes, anxiety, depression or unusual behavior. Seek immediate help for thoughts of self-harm or a sudden mental-health crisis.

Does TRT Increase Cardiovascular Risk?

The relationship between testosterone treatment and cardiovascular health has been studied for years.

Following its review of the TRAVERSE clinical trial, the FDA removed language about increased cardiovascular outcomes from the boxed warning for testosterone products in 2025. The agency reported that the trial did not find an increase in major adverse cardiovascular outcomes among men using testosterone for hypogonadism. However, the FDA also required updated blood-pressure warnings across testosterone products.

This does not mean TRT is free of cardiovascular considerations. A patient’s blood pressure, medical history, symptoms and individual risk factors still matter. Men with cardiovascular conditions should discuss those conditions openly with their healthcare provider.

How Medical Monitoring Helps Manage TRT Side Effects

Proper TRT monitoring begins before the first dose. Treatment should not be prescribed based only on tiredness, reduced motivation or a single unconfirmed test result.

A responsible evaluation may include:

• Review of symptoms and medical history
• Morning testosterone testing
• A repeat measurement when needed to confirm the result
• Hemoglobin and hematocrit
• Blood-pressure assessment
• Discussion of prostate health when appropriate
• Review of fertility plans
• Screening for relevant health conditions and medications

Monitoring continues after treatment begins. Follow-up visits allow the provider to assess symptoms, laboratory results, possible adverse effects and whether the patient is using the medication correctly.

The Endocrine Society recommends evaluating patients after starting therapy to assess their response, possible side effects and adherence to treatment.

Should You Stop TRT if You Notice a Side Effect?

Do not stop, increase or decrease prescribed testosterone on your own unless urgent medical instructions require it.

Contact your provider and explain what changed, when the symptom began and whether it is getting worse. Some concerns may require testing or a treatment adjustment. Others may turn out to be unrelated to testosterone.

Seek emergency care for chest pain, serious breathing problems, fainting, signs of a possible blood clot or stroke, or a severe allergic reaction.

Who Should Be Cautious About Testosterone Therapy?

Testosterone treatment is not appropriate for every man. Extra caution or further evaluation may be necessary for people with certain prostate or breast conditions, elevated hematocrit, untreated severe sleep apnea, uncontrolled heart failure, recent serious cardiovascular events or near-term fertility plans.

This is why an online symptom checklist cannot determine whether someone should begin TRT. Symptoms must be considered together with properly measured testosterone levels, medical history and a provider’s evaluation.

You can read more about what testosterone replacement therapy involves before deciding whether to request an evaluation.

Choosing a TRT 

A Safer Way to Explore TRT in Miami

Understanding TRT side effects should not create unnecessary fear. It should help men approach treatment with realistic expectations and better information.

The safest starting point is a proper evaluation. TRT Miami reviews symptoms, health history, treatment goals and required blood work before a provider decides whether testosterone therapy is appropriate.

Review the TRT consultation process or contact TRT Miami to ask about an in-person consultation at the Miami clinic.

Before starting treatment, learn what to look for when choosing a TRT clinic in Miami.

This article is for general educational purposes and does not provide a diagnosis or replace personalized medical care. Testosterone therapy requires evaluation, a valid prescription and ongoing supervision. Individual responses and results vary.