You have noticed changes in your energy, sex drive, or physical performance. You are wondering whether low testosterone could be involved and whether testosterone replacement therapy is safe.
Online, the answers can sound absolute.
Some messages describe testosterone as dangerous. Others suggest it is the missing ingredient for nearly every man over 40.
The evidence supports a more specific conversation.
Testosterone replacement therapy, or TRT, can benefit men with appropriately diagnosed hypogonadism. Its safety depends on the diagnosis, medical history, treatment regimen, and monitoring. Recent evidence is reassuring about major cardiovascular events in a defined population, but testosterone can increase blood pressure and carries other important risks. Source: Endocrine Society
The starting point is understanding what changed and what still requires attention.
What Did the FDA Change About Testosterone Warnings in 2025?
On February 28, 2025, the FDA announced class-wide labeling changes following its review of the TRAVERSE cardiovascular trial and required ambulatory blood pressure studies.
The changes included:
| Issue | FDA Action |
|---|---|
| Major cardiovascular outcomes | Remove boxed-warning language concerning increased risk of adverse cardiovascular outcomes. |
| TRAVERSE findings | Add the trial results to testosterone product labeling. |
| Age-related low testosterone | Retain the limitation-of-use language. |
| Blood pressure | Add product-specific findings and warnings about increased blood pressure. |
The FDA reported that completed blood pressure studies confirmed increases across testosterone products, class-wide. Source: FDA
Removing cardiovascular boxed-warning language did not mean removing all safety concerns or approving testosterone for every age-related symptom.
What Did the TRAVERSE Trial Actually Show?
TRAVERSE was a large randomized, placebo-controlled trial involving 5,246 men aged 45–80 with symptoms of hypogonadism, repeatedly low testosterone, and existing cardiovascular disease or substantial cardiovascular risk.
Participants received testosterone gel or placebo. Treatment aimed to restore testosterone to a physiological range.
The primary outcome combined cardiovascular death, nonfatal heart attack, and nonfatal stroke.
Testosterone met the trial’s criterion for noninferiority to placebo for that outcome. In plain language, the study did not find an unacceptable increase in these major events within its prespecified statistical framework. Source: New England Journal of Medicine
That is meaningful reassurance for appropriately selected patients.
However, researchers observed higher incidences of atrial fibrillation, acute kidney injury, and pulmonary embolism in the testosterone group. Source: NEJM
The results support a careful benefit-risk discussion rather than a blanket statement that TRT has no cardiovascular risks.
What Does TRAVERSE Not Prove?
The trial does not establish that:
- Testosterone prevents heart attacks.
- Every formulation or dosing strategy has identical risks.
- Supraphysiological testosterone levels are safe.
- Men with normal testosterone benefit from treatment.
- Decades of treatment have been fully evaluated.
Its findings apply most directly to men resembling the study population and receiving a comparable treatment approach.
In 2026, the Endocrine Society continued to emphasize appropriate diagnosis, physiological replacement, and uncertainty about some longer-term outcomes. Source: Endocrine Society
A reassuring result in one setting should not be stretched into approval for unrelated uses.
Can TRT Raise Blood Pressure?
Yes. Increased blood pressure is an important testosterone safety issue.
The FDA’s 2025 action added or strengthened relevant labeling based on ambulatory monitoring studies. Source: FDA
A blood pressure increase may not cause obvious symptoms. Feeling better on treatment does not establish that blood pressure remains controlled.
A practical plan includes:
- A reliable baseline measurement.
- Follow-up after starting treatment or changing the regimen.
- Home readings when appropriate.
- A clear response plan for persistently elevated results.
TRT does not replace treatment of hypertension or other cardiovascular risk factors.
How Can Home Blood Pressure Monitoring Help?
Home readings can help your clinician assess patterns beyond a single office visit.
Measurement technique matters. American Heart Association guidance recommends avoiding smoking, exercise, and caffeine for at least 30 minutes beforehand and supporting the arm at heart level. Source: American Heart Association
Use a validated monitor with a correctly sized cuff and follow the measurement instructions provided by your care team.
Record readings rather than changing treatment independently. Ask your clinician what results should prompt contact and which symptoms require urgent care.
Home monitoring provides information; it does not replace clinical review. Source: American Heart Association
Who Should Be Evaluated for Low Testosterone?
TRT should follow a diagnosis, not a symptom checklist alone.
The Endocrine Society recommends diagnosing hypogonadism in men with compatible symptoms or signs and unequivocally, consistently low testosterone concentrations. A low result should generally be confirmed with another morning fasting measurement. Source: Endocrine Society
Symptoms may include reduced libido, fewer spontaneous erections, and other findings consistent with testosterone deficiency.
Fatigue and poor exercise tolerance are less specific. Sleep apnea, depression, obesity, medications, and other conditions can produce overlapping symptoms or affect testosterone levels.
The VA’s January 2026 guidance emphasizes evaluating those contributors rather than assuming testosterone is the explanation. Source: U.S. Department of Veterans Affairs
One low result does not automatically establish the need for lifelong treatment.
What Should Happen Before Starting TRT?
A thorough assessment should clarify:
- Whether testosterone deficiency is confirmed.
- What may be causing it.
- Whether potentially reversible contributors exist.
- Which symptoms treatment is expected to improve.
- Whether risks or fertility goals change the recommendation.
Depending on the findings, additional evaluation may include free testosterone, luteinizing hormone, follicle-stimulating hormone, or investigation of pituitary and testicular conditions. Source: Endocrine Society
A treatment plan should also identify how response and adverse effects will be assessed.
What Benefits Can Appropriately Prescribed TRT Provide?
Benefits depend on the patient and the reason for treatment.
In men with established hypogonadism, treatment may improve sexual symptoms and selected consequences of testosterone deficiency. Improvements in fatigue, mood, and physical performance are less predictable.
The Endocrine Society’s evidence review found modest average improvements in sexual outcomes, without consistent improvements in energy or mood across the included trials. Source: Journal of Clinical Endocrinology & Metabolism
This is why defining treatment goals matters.
If a laboratory value improves but the symptoms do not, the next step should be reassessment, not an automatic dose increase.
What Other TRT Risks Matter?
Increased Hematocrit
Testosterone can increase red blood cell production.
Hematocrit measures the proportion of blood made up of red blood cells. A substantial increase requires attention and may change treatment.
AUA guidance identifies a hematocrit of 54% or higher during therapy as warranting intervention. This is a clinician-managed decision, not a self-treatment threshold. Source: American Urological Association
Do not assume that routinely donating blood resolves the underlying issue or replaces a review of the regimen and contributing conditions.
Fertility Suppression
TRT can suppress sperm production.
Men who may want biological children should discuss fertility before starting. Standard testosterone replacement should not be presented as a fertility treatment or reliable contraception.
The Endocrine Society recommends against starting TRT in men planning fertility in the near term. Source: Endocrine Society
Prostate-Related Considerations
Prostate history and appropriate screening discussions matter before and during treatment.
Available evidence does not justify saying TRT inevitably causes prostate cancer. It also does not eliminate uncertainty about long-term prostate outcomes.
The Endocrine Society’s 2026 statement emphasizes risk assessment and careful monitoring, noting the limitations of trial duration for a slowly developing disease. Source: Endocrine Society
Formulation-Specific Effects
Different formulations introduce different practical concerns.
Topical products can transfer testosterone through skin contact if precautions are not followed. Injections and pellets have their own administration considerations. Acne, breast symptoms, and other adverse effects may also occur. Source: Endocrine Society
No formulation should be selected solely because it is marketed as the strongest or most convenient.
Who May Need to Delay or Avoid TRT?
Some conditions require treatment first, further investigation, or specialist input.
Examples in Endocrine Society guidance include elevated hematocrit, untreated severe obstructive sleep apnea, uncontrolled heart failure, recent heart attack or stroke, thrombophilia, and certain prostate or breast findings. Source: Endocrine Society
These are reasons for individualized evaluation. They are not a substitute for reviewing the full medical history and current product labeling.
What Monitoring Should Accompany Testosterone Therapy?
Monitoring should examine symptoms and safety, not simply whether testosterone increased.
| Area | Why It Matters |
|---|---|
| Symptoms and function | Determines whether treatment provides meaningful benefit. |
| Testosterone concentration | Helps assess exposure, with blood-draw timing matched to the formulation. |
| Blood pressure | Identifies treatment-associated increases. |
| CBC and hematocrit | Detects excessive red blood cell elevation. |
| Prostate assessment, when appropriate | Supports age- and risk-based follow-up. |
| Sleep, urinary symptoms, and adverse effects | Identifies concerns that may change treatment. |
| Fertility goals | Ensures the plan remains compatible with reproductive priorities. |
AUA guidance emphasizes proper assessment and ongoing monitoring to achieve therapeutic levels and improve symptoms. Source: American Urological Association
How Often Are Checks Needed?
The schedule depends on the formulation, baseline findings, treatment changes, and clinical response.
Endocrine Society guidance includes hematocrit testing at baseline, approximately 3–6 months after initiation, and annually thereafter, with more frequent review when indicated. Testosterone measurements also require formulation-specific timing. Source: Journal of Clinical Endocrinology & Metabolism
Routine intervals are not permission to wait when symptoms or abnormal readings develop.
Is a Higher Testosterone Level Always Better?
No.
The goal of replacement is an appropriate physiological level with meaningful benefit and acceptable risk.
A higher number does not guarantee better energy, sexual function, or performance. It may increase adverse effects.
The Endocrine Society distinguishes treatment of diagnosed hypogonadism from using testosterone to improve appearance, athletic performance, or problems attributed broadly to aging. Source: Endocrine Society
Persistent symptoms deserve investigation rather than a reflexive effort to push the level higher.
What Should You Ask a TRT Provider?
- How was my diagnosis confirmed?
- Could sleep, medications, weight, or another condition explain my symptoms?
- What benefits are realistic for me?
- How will we monitor blood pressure and hematocrit?
- How does this affect fertility?
- Why is this formulation appropriate?
- What happens if the laboratory result improves but I do not feel better?
- Which findings would lead us to adjust or stop treatment?
A clear explanation and follow-up plan are part of responsible care.
Frequently Asked Questions About TRT Safety
Is TRT Safe for the Heart?
TRAVERSE provides reassurance about major cardiovascular events in appropriately selected men with hypogonadism. It does not establish that all cardiovascular risks are absent or that every use is safe. Source: NEJM
Did the FDA Remove All Testosterone Warnings?
No. FDA removed particular cardiovascular boxed-warning language in 2025 while requiring blood pressure warnings and retaining the limitation for age-related hypogonadism. Source: FDA
Can TRT Cause High Blood Pressure?
It can increase blood pressure, making baseline and follow-up assessment important. Source: FDA
Can Men With Heart Disease Receive TRT?
Some may be candidates after evaluation. TRAVERSE included men with existing cardiovascular disease or high risk, but that does not override individual contraindications or recent cardiovascular events. Source: NEJM
Is One Low Testosterone Test Enough?
Generally, no. Diagnosis requires compatible findings and consistently low levels, usually confirmed with repeat morning testing. Source: Endocrine Society
Can TRT Affect Fertility?
Yes. It can suppress sperm production. Discuss reproductive plans before treatment. Source: Endocrine Society
Does TRT Cause Prostate Cancer?
That blanket claim is not established. Prostate risk assessment and monitoring remain important, and longer-term uncertainty persists. Source: Endocrine Society
What Does a High Hematocrit Mean?
It indicates an increased proportion of red blood cells. During TRT, a significant elevation requires clinical assessment and possible treatment changes. Source: American Urological Association
Is Fatigue Always Caused by Low Testosterone?
No. Sleep disorders, medications, mental health conditions, and other medical problems can overlap with suspected low-testosterone symptoms. Source: U.S. Department of Veterans Affairs
Can Monitoring Guarantee TRT Safety?
No. Monitoring helps identify problems and guide decisions, but it cannot eliminate every treatment risk.
Get Answers Before Making a Treatment Decision
If changes in libido, energy, or performance are affecting your life, you deserve an evaluation that looks beyond a single laboratory number.
At 1st Optimal, we help men explore symptoms, health history, testing, and appropriate medical next steps. When indicated, a licensed medical provider can evaluate testosterone deficiency and discuss treatment options.
Book a free consultation with 1st Optimal to discuss your concerns and explore a personalized path forward.
This article provides general education and does not replace individualized medical advice. Testosterone treatment requires evaluation and ongoing care from a licensed medical professional.
