TRT for Transmen: Complete Clinical Guide to Testosterone Therapy

What Is TRT for Transmen and How Does It Differ From Cisgender Male TRT?

Testosterone therapy for transgender men uses FDA-approved testosterone formulations, the same drugs used for cisgender male hypogonadism, but the clinical goal differs. Cisgender male TRT replaces a deficient endogenous supply; gender-affirming testosterone therapy induces full virilization in a person who was not exposed to high-normal male testosterone levels during puberty. That distinction changes target ranges, consent frameworks, and monitoring priorities considerably.

The Endocrine Society's 2017 clinical practice guideline on gender-dysphoric and gender-incongruent persons recommends maintaining serum testosterone in the normal adult male range (400 to 700 ng/dL) and states: "We recommend against starting cross-sex hormone therapy prior to the age of 16 years." [1] WPATH Standards of Care Version 8 (2022) further specifies that informed consent, rather than mandatory psychotherapy letters in most adult cases, is now an acceptable pathway to initiating therapy. [2]

Formulations used for transmen include testosterone cypionate (most common in North America), testosterone enanthate, testosterone undecanoate (Aveed, given every 10 weeks), and transdermal testosterone gel (1.62% or 2%). Subcutaneous injection of cypionate or enanthate has gained ground because it produces smoother serum peaks than intramuscular injection at the same weekly dose. A 2017 study (N=142) published in LGBT Health found that subcutaneous testosterone produced equivalent serum levels with smaller injection volumes and was preferred by 76% of patients who had previously used intramuscular injection. [3]

Dosing Protocols: Starting Doses, Titration, and Target Levels

Most clinicians start testosterone cypionate at 50 mg subcutaneously or intramuscularly once weekly, titrating upward in 10 to 25 mg increments every 6 to 8 weeks until mid-cycle trough levels reach 400 to 700 ng/dL. Typical maintenance doses range from 50 to 100 mg weekly for injections and 40.5 to 103.25 mg daily for gels.

Trough timing matters. For weekly cypionate injections, the trough is drawn just before the next injection. For testosterone undecanoate (Aveed 750 mg/3 mL), levels are checked at week 7 (trough after the second dose) and the target is 400 to 700 ng/dL per the FDA prescribing information. [4] Overdosing pushes hematocrit above 50%, raising stroke and deep-vein thrombosis risk; underdosing prolongs dysphoria and slows virilization.

The Endocrine Society guideline recommends measuring serum testosterone at 3-month intervals until stable, then annually. [1] Estradiol does not need routine monitoring in transmen on adequate testosterone doses because gonadal estrogen production falls as luteinizing hormone (LH) suppression deepens, though residual ovarian estradiol can persist, especially in the first 1 to 2 years before amenorrhea is fully established.

The HealthRX clinical team uses a four-tier titration ladder for transmen initiating testosterone:

• Tier 1 (weeks 0, 12): Testosterone cypionate 50 mg SC weekly. Labs at week 6 and week 12. Target trough 300 to 500 ng/dL.
• Tier 2 (weeks 12, 24): Increase to 75 mg SC weekly if trough <400 ng/dL and hematocrit <48%. Labs at week 18.
• Tier 3 (months 6, 12): Increase to 100 mg SC weekly if virilization is incomplete and labs remain within safety range.
• Tier 4 (month 12 onward): Individualize. Some transmen reach steady state at 60 mg; others need 100 mg. Annual labs thereafter unless concerns arise.

Timeline of Virilizing Changes

Voice deepening begins between weeks 3 and 12 in most transmen and is largely complete by 12 to 24 months. [5] Clitoral growth (clitoromegaly) starts within the first 1 to 3 months. Facial hair grows slowly; a full beard may take 3 to 5 years and is heavily genetically determined.

Body fat redistributes toward the abdomen within 3 to 6 months, and lean muscle mass increases measurably by month 6 in individuals who exercise. A 2019 prospective study (N=247) in The Journal of Clinical Endocrinology and Metabolism showed that transmen gained an average of 3.9 kg of lean mass and lost 2.7 kg of fat mass over 12 months of testosterone therapy, without any structured exercise intervention. [6]

Menses typically cease within 6 months; amenorrhea rates reach roughly 80% by month 6 and over 95% by month 12. [5] Persistent breakthrough bleeding beyond 12 months warrants gynecologic evaluation to rule out endometrial pathology.

TRT for Younger Transmen (Ages 16, 30)

Younger transmen starting testosterone before age 25 are still accruing peak bone mass, so adequate calcium (1,000, 1 to 300 mg/day) and vitamin D (600 to 800 IU/day, or more if deficient) intake is a clinical priority. [7] Long-term data from the Amsterdam cohort show that transmen who started testosterone before age 30 achieved bone mineral density within 0.5 standard deviations of cisgender male norms after 10 years of therapy. [8]

Fertility preservation deserves an explicit conversation before the first injection. Even a few weeks of testosterone can suppress ovarian function and reduce oocyte yield at retrieval, though it is not reliably contraceptive. The American Society for Reproductive Medicine (ASRM) states that transgender individuals should be counseled about fertility preservation options before initiating any gender-affirming hormone therapy. [9] Oocyte or embryo cryopreservation requires a hormone stimulation cycle that temporarily pauses testosterone, which is emotionally difficult but medically feasible.

Erythrocytosis is less common in younger transmen than in those over 50, but hematocrit still needs checking at 3 months because some individuals are outlier responders regardless of age.

TRT Over 50: Cardiovascular and Metabolic Considerations

Transmen over 50 carry the same cardiovascular risk factors that complicate cisgender male TRT in older age groups. The TRAVERSE trial (N=5,246 cisgender men aged 45, 80 with hypogonadism and elevated cardiovascular risk) found that testosterone replacement was non-inferior to placebo for major adverse cardiovascular events (MACE) over a mean follow-up of 33 months, but pulmonary embolism occurred in 0.9% of testosterone-treated men vs. 0.5% on placebo (P<0.001). [10] Those findings are clinically transferable to older transmen.

Polycythemia is the dominant safety concern after age 50. Testosterone stimulates erythropoiesis via erythropoietin and direct bone marrow effects; hematocrit frequently rises above 48% in transmen on doses above 75 mg weekly. [11] The Endocrine Society recommends holding therapy if hematocrit exceeds 50% and reducing the dose or switching to a lower-peak formulation (gel rather than injection) once levels normalize. [1]

Lipid panels also shift. Total and LDL cholesterol may rise modestly, and HDL cholesterol typically falls by 10 to 15% in the first year of testosterone therapy. A meta-analysis in Obesity Reviews (2019, 27 studies, N=1,991 transgender men) reported a mean HDL decline of 9.8 mg/dL after 12 months of testosterone. [12] For transmen over 50 who already have borderline lipids, statin therapy or dietary modification before starting testosterone can reduce net cardiovascular risk.

Blood pressure monitoring every 6 months is appropriate for transmen over 50. Testosterone can raise systolic blood pressure by 3 to 5 mmHg on average, a modest but additive effect in those with pre-existing hypertension. [13]

TRT Over 65: Special Populations and Reduced-Dose Protocols

Transmen over 65 are a small but growing clinical population as the first generation of adults who transitioned in the 1990s and 2000s reaches older age. Data specific to this group are sparse, but guidance from cisgender male endocrinology applies: keep hematocrit below 50%, monitor for sleep apnea (testosterone worsens upper-airway tone), and assess fall risk before and during therapy. [1]

Bone health becomes a primary concern. Post-menopausal transmen (those whose gonads have been removed or who are functionally hypogonadal from long-term LH suppression) who let testosterone levels fall below 200 ng/dL risk accelerated trabecular bone loss. Dual-energy X-ray absorptiometry (DEXA) every 2 years is standard practice in this group. [14]

Some clinicians reduce the weekly testosterone cypionate dose to 40 to 60 mg in transmen over 65 to minimize erythrocytosis while maintaining serum levels at 300 to 500 ng/dL, a range that preserves bone density and mood without driving hematocrit above safe thresholds. Testosterone gel 1.62% (one to two pump actuations daily) is a reasonable alternative because it produces lower peak serum levels and a flatter diurnal curve. [4]

TRT and Bodybuilding in Transmen: Risks of Supraphysiologic Dosing

Some transmen who train competitively use testosterone at doses well above the 50 to 100 mg weekly range, sometimes 200 to 400 mg weekly or higher, crossing into anabolic steroid territory. This is worth addressing directly because patients may not volunteer this information without a nonjudgmental clinical environment.

Supraphysiologic testosterone produces rapid lean mass gains. A landmark NEJM study by Bhasin et al. (N=43, 1996) showed that testosterone enanthate 600 mg weekly for 10 weeks increased fat-free mass by 6.1 kg compared with 2.0 kg in the exercise-only, placebo group (P<0.001), demonstrating a clear dose-response effect. [15] However, doses above 200 mg weekly consistently drive hematocrit above 52%, suppress endogenous LH to undetectable levels, and cause left ventricular hypertrophy with chronic use. [16]

Hepatotoxicity is not a primary concern with injectable testosterone esters (it is a concern with oral 17-alpha-alkylated androgens like oxandrolone or stanozolol, which some bodybuilders stack with testosterone). [17] Acne and androgenetic alopecia accelerate markedly at supraphysiologic doses.

The clinical recommendation is clear: document the actual dose the patient is using, monitor hematocrit every 3 months (not annually), obtain an echocardiogram if the patient has used supraphysiologic doses for more than 12 months, and discuss harm-reduction strategies including dose reduction targets. The FDA has not approved any testosterone product for athletic performance enhancement, and supraphysiologic use is outside the scope of gender-affirming care guidelines from both WPATH and the Endocrine Society. [2] [1]

Monitoring Schedule: Labs, Imaging, and Clinical Assessments

Consistent monitoring reduces serious adverse events. The table below summarizes the standard schedule recommended by the Endocrine Society (2017) and augmented by HealthRX clinical protocols.

At baseline: serum total testosterone, hematocrit/hemoglobin, fasting lipids, blood pressure, weight, BMI, DEXA if risk factors for osteoporosis, and a pregnancy test if there is any possibility of pregnancy.

At 3 months: serum testosterone trough (just before next injection), hematocrit, and blood pressure. Adjust dose based on trough level and hematocrit.

At 6 months: serum testosterone, hematocrit, lipids, liver enzymes (if oral androgens are co-used), and weight. Pap smear or vaginal cytology per gynecologic guidelines if cervix is intact. The American Cancer Society notes that transgender men with a cervix should follow the same cervical cancer screening intervals as cisgender women (every 3 years with cytology alone, or every 5 years with co-testing, from age 25). [18]

Annually: all the above plus DEXA every 2 years in those over 60 or post-gonadectomy. Prostate screening is not indicated unless prostate tissue is present (rare scenario in transmen who have had phalloplasty with urethral lengthening using scrotal tissue). [1]

Dr. Vin Tangpricha, a co-author of the Endocrine Society 2017 guideline, has written: "Monitoring testosterone levels in transgender men is essential not only for efficacy but also for safety, particularly given the risk of erythrocytosis and its cardiovascular sequelae." [1] That guidance is reflected in the HealthRX monitoring intervals above.

Fertility Preservation Before and During TRT

Testosterone is not a reliable contraceptive. Pregnancies have been documented in transmen on testosterone therapy, though the rate is low. A 2019 case series in Obstetrics and Gynecology (N=18 transmen who became pregnant while on or shortly after stopping testosterone) showed that all 18 achieved successful pregnancies after stopping testosterone, and 17 of 18 resumed amenorrhea within 6 months of restarting therapy post-partum. [19]

For transmen who want biological children before or after transition, options include:

1. Oocyte cryopreservation before starting testosterone (highest yield, straightforward protocol).
2. Embryo cryopreservation with a partner or donor sperm before starting testosterone.
3. Temporary testosterone cessation for ovarian stimulation after years of therapy (lower oocyte yield due to ovarian aging and possible atrophy, but feasible).

ASRM recommends that all clinicians initiating gender-affirming hormones discuss fertility preservation and refer patients to a reproductive endocrinologist if they express any interest in future biological parenthood. [9] This conversation should happen at the very first visit, before the prescription is written.

Drug Interactions and Contraindications

Testosterone cypionate and enanthate are metabolized primarily by CYP3A4. Strong CYP3A4 inhibitors (ketoconazole, ritonavir, clarithromycin) can raise testosterone exposure; inducers (rifampin, carbamazepine, phenytoin) can lower it. Dose adjustment and more frequent monitoring are appropriate when these drugs are co-prescribed. [4]

Absolute contraindications to testosterone therapy include: known or suspected hormone-sensitive cancer (e.g., breast cancer, though evidence is limited for transmen specifically), untreated severe sleep apnea, hematocrit above 50% at baseline, and hypersensitivity to any component of the formulation. [1] Relative contraindications include: active thromboembolic disease, uncontrolled heart failure, and severe untreated hypertension.

Warfarin anticoagulation levels (INR) can rise with testosterone co-administration due to increased sensitivity to warfarin, so INR should be checked 2 to 4 weeks after any dose change in patients on warfarin. [4]

Insurance Coverage and Access

Coverage varies widely. As of 2023, most major commercial insurers cover testosterone formulations for gender dysphoria under the ACA's nondiscrimination provisions, but prior authorization requirements and formulary restrictions remain common. Medicare covers testosterone as a covered Part B drug when administered in-office (Aveed) or as a Part D outpatient pharmacy benefit for self-administered formulations. Generic testosterone cypionate 200 mg/mL vials cost as little as $30, $60 per month without insurance at major pharmacy chains, making it one of the most accessible gender-affirming medications available. [20]