Protocols vary by country and labeling; some clinics discuss weekly use while others extend the interval. The schedule (initial dose, another at 4 weeks, then about every 10 weeks) aims to maintain a relatively flat level with supervised monitoring. Long-acting testosterone undecanoate (e.g., Aveed® in the U.S.) is typically administered in clinic because of rare but serious oil-embolism reactions. General pharmacokinetic comparisons appear in the TRT pharmacology review (PMC). Label presentations and administration details for injectable formulations are summarized on Mayo Clinic’s drug page and in the Drugs.com monograph. You can see the labeled ranges in the Drugs.com dosage monograph, while monitoring/titration principles are detailed in the Endocrine Society guideline. Drug references explicitly note that dosing should be individualized to response and adverse effects, not set-and-forget (see the Drugs.com dosage monograph). Safety monitoring typically includes hematocrit (screen for erythrocytosis), PSA and prostate assessment as age-appropriate, blood pressure, and a lipid profile. Mainstream guidance emphasizes titrating to symptom relief and aligning lab timing with the formulation (e.g., the Endocrine Society’s detailed recommendations in J Clin Endocrinol Metab, 2018 and this concise AUA educational update). After a dose change, follow-up commonly occurs at 3–6 months, then periodically once stable. There’s no precise "X mg → Y ng/dL" conversion because absorption, SHBG, body size, and timing of the lab draw vary. Many stabilize in a mid-normal serum range using totals around ~75–150 mg/week for short-acting injectables, but outliers exist due to differences in absorption, SHBG, body size, and comorbidities. Converting mg to mL accurately ensures you’re delivering the intended amount—so your blood tests truly reflect your plan and your clinician can adjust precisely. You’ll find labeled strengths and administration details in the Drugs.com dosage monograph and the Mayo Clinic route-specific page. These conversions matter when you and your clinician agree on a weekly target and whether you’ll inject IM (into muscle) or SC (into the fat just beneath the skin). A pharmacology overview explaining how ester length affects blood levels is available in this peer-reviewed review (PMC). Most clinics start with a conservative weekly total and then titrate to symptoms and labs. For example, entering 120 mg/week with a 200 mg/mL vial and twice-weekly frequency should output 60 mg per shot (0.3 mL each time). The ISSWSH 2021 guideline likewise recommends transdermal options (e.g., gels/creams titrated down from male products) with careful monitoring of testosterone, SHBG, and clinical response (ISSWSH Clinical Practice Guideline, 2021). For cisgender women, systemic testosterone is occasionally used for distressing low sexual desire after other causes are addressed—specifically, hypoactive sexual desire disorder (HSDD). Interventions are common if hematocrit approaches about 54%, and clinicians individualize prostate monitoring by age and risk (summarized in the AUA Testosterone Deficiency Guideline). Continue reading to learn more about these types of injections and to get specific instructions for each. The injection needle should be new and in its protective packaging. Then remove the drawing needle from the syringe and replace it with the injection needle. Make sure to use a new drawing needle, new injection needle, and new alcohol wipes each time. Testosterone injections are one of the most common forms of Testosterone Replacement Therapy. If your numbers or side effects drift, your clinician changes the weekly trt dose, and the calculator simply re-splits it.
