Preparing properly for your venous blood test ensures your hormone levels and safety markers are measured accurately, helping your clinician make the right decisions for your Testosterone Replacement Therapy (TRT) care.
Timing of Your Appointment
Morning Blood Draws: Schedule your appointment in the morning whenever possible—ideally between 7:00 AM and 11:00 AM. Testosterone levels naturally peak during the early morning hours, and clinical reference ranges are built around this window.
Medication & Gel Timing Guidelines
If you are currently on TRT, how and when you take your medication can directly impact your results. Follow these rules for your specific treatment type:
Testogel (Gel): Book your appointment at least 4 hours after your morning application. Where possible, try to avoid applying to elbow flexures and the inside of arms on the day of your test; you can use alternative sites where there is still little hair in the area—such as the backs of upper arms or shoulders, across the abdomen, backs of knees, or inner thighs—to avoid contaminating the sample.
Cypionate (Injectable): Schedule your test on your regular injection day, but make sure you do not take your injection until after your blood sample has been drawn.
Kyzatrex (Oral): Schedule your appointment 3 to 5 hours after your morning dose. Take your afternoon dose only after the blood test is completed.
Clomid or hCG Monotherapy: Attend your morning appointment between 7:00 AM and 11:00 AM. If you take hCG, ensure the blood draw happens before your injection that day.
Supplements and Products to Avoid
Certain over-the-counter products and supplements can interfere with hormone assays or lab markers. Avoid the following prior to your test:
Testosterone Boosters: Pause natural or herbal testosterone boosters (such as Ashwagandha, Tongkat Ali, or D-Aspartic Acid) for at least 2 to 3 days prior to testing.
Biotin (Vitamin B7): Stop taking high-dose biotin supplements at least 48 to 72 hours before your test, as biotin can interfere with various hormone and thyroid lab assays.
Hydration & Fasting
Stay Hydrated: Drink plenty of plain water the night before and the morning of your test. Good hydration makes your veins easier to find and speeds up the blood draw process.
Fasting: Fasting requirements depend on your specific medication protocol. Please note that Kyzatrex blood tests are not fasted, as this medication needs to be taken with healthy fats to aid absorption. Only fast for 8 hours prior if explicitly instructed by your specific non-Kyzatrex protocol.