Common side effects
Reported side effects of testosterone injections include:
- Acne or oily skin
- Pain, redness or bruising where the injection is given
- Swelling of the hands, feet, ankles or lower legs from fluid retention
- Breast tenderness or enlargement
- Mood changes, trouble sleeping or headaches
- Joint or back pain
Many people have none of these, or mild ones. Tell your clinician about any that bother you.
Risks that need monitoring
Some effects of testosterone don’t cause symptoms at first, which is why blood tests and checkups continue while you are on it:
- Red blood cell count. Testosterone can raise it, which can make the blood thicker.
- Blood pressure. The FDA added warnings in 2025 that testosterone products can raise blood pressure.
- Prostate. Testosterone may increase the risk of prostate problems, so your provider may check your prostate as recommended for your age.
- Breathing during sleep. Testosterone can make sleep apnea worse.
- Fertility. Testosterone can lower sperm production. If you hope to father a child, tell your provider before starting.
In 2025, the FDA also updated testosterone labels after a large study found no increase in heart attack or stroke risk in men treated for low testosterone. The labels still say testosterone is not approved for low levels caused by age alone.
Who should not take testosterone
Testosterone is usually not appropriate if you:
- Have, or may have, prostate cancer or breast cancer
- Have normal testosterone on repeat blood tests
- Are pregnant or could become pregnant, or are breastfeeding
- Hope to father a child soon
- Want it for bodybuilding, athletic performance or anti-aging
Your provider also reviews other conditions, such as heart disease, sleep apnea and a high red blood cell count, before discussing treatment.
Questions to ask before you start
- Do my blood tests confirm low testosterone, and what is causing it?
- How will the medicine be given, and how often will I be seen?
- Which blood tests will be repeated, and how often?
- What side effects should I call about?
- What are my other options?
Talk with our Frisco team
Testosterone therapy at our Frisco office starts with a consultation and an evaluation, separate from a pain management visit. Learn more about testosterone therapy in Frisco and how low testosterone is diagnosed, or call 214-618-9600 or request a consultation.
Call 911 for chest pain, trouble breathing, or sudden weakness or trouble speaking. Get medical care right away for pain, swelling, warmth or redness in one leg.