What are the recommended monitoring and management guidelines for a female to male patient taking 100 mg of testosterone cypionate (testosterone cypionate) weekly?

Monitoring and Management for Female-to-Male Transgender Patient on 100 mg Testosterone Cypionate Weekly

For a female-to-male transgender patient on 100 mg testosterone cypionate weekly, monitor testosterone levels at 2-3 months initially (targeting mid-normal male range of 450-600 ng/dL), then every 6-12 months once stable, while checking hematocrit/hemoglobin, lipids, and assessing for masculinization effects and amenorrhea at each visit. 1

Initial Monitoring Timeline

First follow-up should occur at 1-2 months to assess early treatment response and tolerability, with consideration for dose adjustment if clinical response is inadequate. 2

• Testosterone levels should be measured at 2-3 months after treatment initiation or any dose change, drawn midway between injections (approximately 3-4 days after injection for weekly dosing). 1
• Target testosterone levels should be in the mid-normal male range of 450-600 ng/dL. 2, 1
• Once stable therapeutic levels are achieved, monitoring intervals extend to every 6-12 months. 1

Laboratory Monitoring Parameters

Essential Labs at Each Visit

• Serum testosterone levels (total testosterone, measured midway between injections). 2, 1
• Hematocrit or hemoglobin to monitor for erythrocytosis, which occurs more frequently with injectable formulations. 2, 1
• Lipid panel should be obtained, though some sources consider this optional in cisgender male populations. 2

Baseline Laboratory Assessment

Before initiating therapy or at first visit if already on therapy:

• Baseline testosterone level 1
• Baseline hematocrit/hemoglobin 2
• Baseline lipid panel 2
• Baseline estradiol level (particularly relevant for FTM patients) 3

Clinical Assessment at Each Visit

Masculinization Effects to Monitor

• Amenorrhea status (if premenopausal/pre-hysterectomy) - expected in most patients on adequate therapy. 3
• Voice deepening 3
• Facial and body hair growth 3
• Body fat redistribution 3
• Muscle mass changes 4

Symptom Assessment

• Mood and sense of well-being - improvement expected with adequate therapy. 4
• Energy levels and vitality 4
• Libido and sexual function 4
• Sleep quality and assessment for sleep apnea symptoms (testosterone can worsen sleep apnea). 2

Adverse Effects Surveillance

• Injection site reactions: pain, soreness, bruising, erythema, swelling, nodules, or furuncles at IM injection sites. 2
• Acne, oily skin, increased body hair - common but generally minor. 2
• Fluid retention - uncommon but use caution if patient has cardiac or renal issues. 2
• Cardiovascular symptoms - chest pain, shortness of breath, leg swelling. 4

Dose Adjustment Strategy

The 100 mg weekly dose is appropriate and within standard dosing ranges for FTM transgender patients (typical range 50-150 mg weekly). 1, 3

When to Adjust Dose

• If testosterone levels are below mid-normal range (450-600 ng/dL) AND clinical response is suboptimal, increase the dose. 2
• If patient reports adequate clinical response, no dose adjustment is needed even if levels are in the low-normal range. 2
• If hematocrit rises above the reference range, consider temporarily withholding therapy, reducing dose, or performing phlebotomy. 2

Dosing Considerations

• Weekly dosing of 50-100 mg provides more stable testosterone levels compared to biweekly administration of 100-200 mg, which reduces adverse effects including erythrocytosis and potentially cardiovascular risk. 1
• Peak serum testosterone levels occur 2-5 days after injection, and levels often return toward baseline by 10-14 days with biweekly dosing. 2

Special Monitoring Considerations for FTM Patients

Fertility Counseling

• Exogenous testosterone therapy severely compromises fertility through down-regulation of gonadotropins and can cause oligospermia or azoospermia. 2
• Patients desiring future fertility should be counseled before initiating therapy. 2

Estradiol Monitoring

• Among premenopausal FTM patients, achieving serum estradiol concentrations <50 pg/mL is a reasonable target along with amenorrhea. 3
• Lower estradiol levels are associated with successful masculinization. 3

Cardiovascular Risk Assessment

• Cardiovascular risk factors should be assessed before and during therapy, as the FDA warns that testosterone may increase cardiovascular risk. 1, 4
• Injectable testosterone may carry greater cardiovascular risk compared to transdermal preparations, possibly due to fluctuating testosterone levels. 1
• Testosterone therapy should not be commenced for 3-6 months in patients with recent cardiovascular events (myocardial infarction, stroke). 2

Common Pitfalls to Avoid

• Do not check testosterone levels at random times - always measure midway between injections for accurate assessment. 1
• Do not ignore rising hematocrit - erythrocytosis is more common with injectable formulations and requires dose reduction or phlebotomy if above normal range. 2, 1
• Do not continue escalating doses if clinical response is adequate - even if testosterone levels are low-normal, adequate symptom control does not require dose increase. 2
• Do not overlook cardiovascular risk factors - assess and manage hypertension, diabetes, hyperlipidemia, and obesity concurrently. 1, 4

Alternative Administration Route

Subcutaneous (SC) injection is an effective and preferred alternative to intramuscular injection for many FTM patients, achieving therapeutic testosterone levels (50-150 mg weekly) with less discomfort, easier self-administration, and potentially lower rates of erythrocytosis and estradiol elevation. 1, 3, 5

• All 22 patients who switched from IM to SC in one study had mild or marked preference for SC injections. 3
• SC testosterone provides stable serum levels between weekly injections without the peaks and troughs seen with IM administration. 5