Important safety information
Read this before starting any treatment offered through Xilo. It is a summary, not the complete prescribing information, and it does not replace the conversation with your provider.
Last updated 14 August 2026
Emergency
If you have chest pain, shortness of breath, weakness or numbness on one side, swelling or pain in a leg, or sudden vision change, stop taking your medication and seek emergency care or call 911. If you are in crisis or thinking about harming yourself, call or text 988 to reach the Suicide and Crisis Lifeline.
Who should not start treatment
A licensed provider will not prescribe hormone therapy where any of the following applies, and may decline for reasons not listed here:
- Active or suspected prostate cancer or breast cancer.
- Hematocrit above the accepted safety threshold before treatment.
- Untreated obstructive sleep apnea.
- Unstable cardiac disease, recent cardiovascular event, or uncontrolled heart failure.
- Significant liver or kidney impairment.
- A current desire to conceive, where the therapy under consideration may suppress sperm production.
- Known hypersensitivity to the medication or any of its components.
- Age under 18.
Reported side effects
More commonly reported effects include headache, nausea, acne, changes in mood, changes in sleep, and breast tenderness. These are often mild, but report anything persistent rather than adjusting your own dose.
Less common but serious effects include visual disturbance, venous thromboembolism, a clinically significant rise in hematocrit requiring dose reduction or discontinuation, mood disturbance including worsening depression, and effects on fertility. Where a medication for erectile function is prescribed alongside, additional risks apply, including a sudden drop in blood pressure if taken with nitrates, and prolonged erection requiring urgent care.
Interactions to disclose
Tell your provider about every medication and supplement you take, and specifically about nitrates, alpha blockers, anticoagulants, and any hormone therapy. Do not start any medication prescribed through Xilo alongside another testosterone product without telling your provider.
Monitoring
Treatment through Xilo includes follow-up laboratory testing. Monitoring exists to detect changes in hematocrit, hormone levels, and other safety markers before they become clinically significant. Declining follow-up testing may result in treatment being discontinued.
Compounded products
Where a compounded drug product is used, that product is not approved by the FDA, and the FDA does not evaluate compounded drugs for safety, effectiveness, or quality.
Research supply materials
This page concerns telehealth treatment only. Materials sold through Xilo Research Supply are laboratory reference materials for in-vitro research, are not for human or veterinary use, and have no safety profile established for human administration. See the research use policy.