Common Side Effects of Xyosted
Xyosted, a weekly subcutaneous testosterone enanthate injection for hypogonadism in adult males, causes side effects linked to elevated testosterone levels. Patients most often report increased red blood cell count (polycythemia), which raises stroke or blood clot risk; hypertension; acne; injection site reactions like pain or bruising; and prostate enlargement or PSA elevation.[1][2]
Serious Risks and Warnings
Black box warnings highlight potential for blood clots (deep vein thrombosis or pulmonary embolism), heart attack, stroke, and prostate cancer promotion due to androgen effects. Other severe effects include liver problems (jaundice, tumors), sleep apnea worsening, aggressive behavior or mood changes, gynecomastia (breast enlargement), testicular shrinkage, and infertility from suppressed sperm production.[1][2][3]
What Happens If You Increase the Dose?
Higher doses amplify risks like cardiovascular events and polycythemia. Clinical data show dose-dependent erythrocytosis in up to 40% of users; monitor hematocrit regularly and phlebotomize if over 54%.[2][4]
Side Effects in Older Men vs. Younger Patients
Men over 65 face higher cardiovascular and prostate risks; studies note 2-3x greater incidence of events like myocardial infarction compared to younger groups. Baseline PSA and hematocrit screening is critical for all, but especially seniors.[2][3]
How Long Do Side Effects Last?
Acute effects like acne or mood shifts resolve within weeks of stopping or dose adjustment. Long-term issues like infertility may persist months post-discontinuation due to hypothalamic-pituitary suppression; polycythemia normalizes in 1-3 months with treatment.[1][4]
Monitoring and Management Tips
Doctors check blood pressure, hematocrit, PSA, and lipids every 3-6 months. Manage polycythemia via blood donation; treat acne topically; report chest pain or leg swelling immediately.[1][2]
Compared to Other Testosterone Therapies
Xyosted's weekly auto-injector profile shows similar side effects to gels (e.g., AndroGel) or patches, but lower skin transfer risk and steadier levels than biweekly shots. Injection-site issues occur in 10-20% vs. 5% for gels; polycythemia rates match across forms.[3][4]
[1]: Xyosted Prescribing Information (FDA-approved label)
[2]: Antares Pharma (manufacturer) safety data
[3]: Drugs.com Xyosted side effects
[4]: PubMed review on testosterone therapy adverse events