Guidelines for Testosterone Replacement Therapy: Administration, Monitoring, and Contraindications

Monitoring Parameters

Hematocrit should be measured at baseline, again at 3–6 months after initiating therapy, and then annually; therapy should be discontinued if hematocrit exceeds 54 % (Endocrine clinical guidelines) 1, 2
For men aged ≥ 40 years, obtain a baseline prostate‑specific antigen (PSA) level and digital rectal examination, and repeat PSA testing at 3–6 months and annually thereafter (Endocrine clinical guidelines) 1, 2
Regardless of injection route, all patients require periodic assessment of serum testosterone levels, hematocrit, and PSA (in men ≥ 40 years) to ensure therapeutic efficacy and safety (Endocrine clinical guidelines) 1, 2

Guidelines published up to 2017 designate testosterone cypionate and enanthate as intramuscular (IM) formulations, recommending injection into the thigh (for self‑administration) or gluteal muscle (when administered by another person) (Endocrine clinical guidelines) 1, 3, 4

Absolute contraindications to testosterone therapy include prostate cancer, breast cancer, baseline hematocrit > 50 %, and untreated severe obstructive sleep apnea (Endocrine clinical guidelines) 1, 2

Long‑acting testosterone undecanoate (750 mg every 10 weeks) is specifically labeled for gluteal intramuscular injection only; subcutaneous administration is contraindicated because of the risk of pulmonary oil micro‑embolism (Endocrine clinical guidelines) 1, 3, 4