The most consistently seen effects are an increase in red blood cell concentration, changes in blood pressure, suppression of sperm production, acne or skin changes, and site-specific issues depending on the route used. Men with untreated sleep apnea, certain cardiac conditions, prostate cancer or a strong desire for near-term fertility may not be appropriate candidates at all.
Equally important is what testosterone will not do. It does not treat depression that is not driven by hormone deficiency, it does not substitute for sleep, training or diet, and it is not a performance enhancer we prescribe for the gym. When a man's numbers are normal, therapy is unlikely to be the answer to how he feels.
FDA labeling for the class was updated in 2025. That update removed the boxed cardiovascular warning in light of trial evidence and added warnings about blood pressure increases. That is a refinement of what we know, not a statement that testosterone carries no cardiovascular considerations.
Risks and limitations
- Elevated hematocrit may require dose reduction, interruption or discontinuation.
- Blood pressure can rise; FDA labeling specifically warns about this.
- Fertility suppression is common and may be prolonged.
- Existing sleep apnea may worsen; several conditions make therapy inappropriate.
- Long-term data continue to evolve, and honest uncertainty remains in some areas.