Peptides Clarified

Hormone therapy

Testosterone therapy (TRT)

Also known as: TRT, testosterone replacement therapy, testosterone cypionate, testosterone gel

FDA-approvedEvidence: Established

Plain-language summary

Prescription testosterone (injections, gels, patches, pellets) FDA-approved to treat hypogonadism in males from identifiable medical conditions — not age-related low testosterone alone.

Regulatory status

Evidence snapshot

Established. Supported by multiple well-conducted randomized trials and/or systematic reviews with consistent results.

How it works

Supplies exogenous testosterone to restore levels in men who cannot produce adequate amounts, supporting sexual function, muscle and bone, and other androgen-dependent functions.

Approved uses and researched uses

FDA-approved uses

  • Replacement therapy in males with primary hypogonadism (congenital or acquired)
  • Replacement therapy in males with hypogonadotropic (secondary) hypogonadism (congenital or acquired)

Researched (not approved) uses

  • Age-related "low T" symptoms (not an approved indication)
  • Low libido in idiopathic hypogonadism (under FDA discussion)
  • Body composition and mood effects

Researched uses are studied but not FDA-approved and may be off-label. This is not a recommendation to use them.

Known risks and uncertainties

Potential effects include acne, fluid retention, elevated red-blood-cell count (polycythemia), reduced sperm production and fertility, worsening sleep apnea, and small increases in blood pressure and atrial fibrillation. A 2025 class-wide label update reflects TRAVERSE cardiovascular findings. Testosterone is a Schedule III controlled substance.

Cautions and contraindications

Contraindicated in men with breast cancer or known/suspected prostate cancer, and generally avoided in men seeking fertility or with untreated severe sleep apnea or very high red-blood-cell counts. Not indicated purely for age-related testosterone decline.

Consumer considerations

  • Approval is for diagnosed hypogonadism, not simply low-normal or age-related testosterone.
  • Diagnosis typically requires confirmed low morning testosterone plus symptoms.
  • It can reduce fertility, which matters for men who want children.
  • Requires monitoring of blood counts, PSA, and blood pressure.
  • It is a controlled substance with recognized misuse potential.

Questions to ask a licensed clinician

  • Have my testosterone levels been confirmed low on more than one morning test?
  • What is the underlying cause of my low testosterone?
  • How will this affect my fertility and can that be managed?
  • What monitoring (blood count, PSA, blood pressure) will I need?
  • What do the latest cardiovascular safety data mean for me?

Sources

Primary and authoritative sources

  1. 1.FDA issues class-wide labeling changes for testosterone products — U.S. Food and Drug Administration. Government agencyAccessed July 24, 2026.
  2. 2.DailyMed — Testosterone Cypionate label — U.S. National Library of Medicine (DailyMed). Government agencyAccessed July 24, 2026.
Last reviewed (yesterday)

Reviewed by Peptides Clarified Editorial — Editorial sourcing review — licensed clinical review pending.