Testosterone therapy for men
For confirmed deficiency, not just a low number.
VIDEO LESSON
How it's taken
• Gel: daily on the skin
• Injection: weekly under the skin or every 1 to 2 weeks into muscle; long-acting forms less often
• Oral capsules: twice daily with food
• Nasal gel: several times daily
Side effects at a glance
• Acne and oily skin
• Rising hematocrit
• Fluid retention and breast tenderness
• Lower sperm count and smaller testes
Rare but serious
• Very high hematocrit
• Blood pressure increases with some oral forms (boxed warning)
• Virilization in women or children exposed to gel: cover the site and wash hands
Monitoring
Testosterone, hematocrit and PSA at 3 to 6 months, then yearly.
Good to know
Testosterone is not a fertility treatment: it suppresses sperm production.
AT A GLANCE
Class
Men’s health
Brand names
AndroGel, Testim, Xyosted, Jatenzo, Tlando, Kyzatrex, Natesto, Aveed
Status
FDA-approved
Reviewed by
Farhan Tahir, MD
Is this medicine right for you?
Prescription medicines need individual medical advice. Dr. Tahir’s team offers consults through Youthful Medicine.
MECHANISM
How it works
Replaces testosterone by gel, injection, patch, pellet or oral capsule. It acts on androgen receptors in muscle, bone, brain and bone marrow, and part of it is converted to estradiol, which men also need for bone and brain health.
THE EVIDENCE
What the research actually shows.
EVIDENCE SUMMARY
The American Urological Association defines low testosterone as a total level below 300 ng/dL on two separate early-morning tests, together with symptoms. In TRAVERSE, 5,246 men aged 45 to 80 with low testosterone and existing or high cardiovascular risk had no increase in major cardiovascular events on testosterone gel (7.0% vs 7.3% on placebo; hazard ratio 0.96).
KEY TRIALS
TRAVERSE
TYPICAL RESULT
No increase in major cardiac events (HR 0.96)
SAFETY
Risks, side effects and who should avoid it
TRAVERSE found more atrial fibrillation, acute kidney injury and pulmonary embolism with testosterone, and a fracture substudy found more fractures (3.5% vs 2.5%). Testosterone suppresses sperm production, so it is not for men trying to conceive. Hematocrit and PSA need regular monitoring.
This summary is not a complete list of risks. Read the official prescribing information and discuss your own history with your clinician.
KEY REFERENCE
Lincoff AM et al. Cardiovascular safety of testosterone-replacement therapy. N Engl J Med 2023;389:107–117.
Educational content only, reviewed by Farhan Tahir, MD. Not individual medical advice. Medicines named here require a prescription and medical supervision.