Testosterone & Hormones
Morning vs Evening Testosterone: When to Test and Why It Matters
Testosterone follows a daily rhythm. Test at the wrong time and the number lies.
5 min read · XT Editorial Team · Reviewed & updated
The diurnal pattern
Testosterone peaks between 6 and 10 AM, then drops 25-50% by evening. Always test in the morning window for comparable numbers.
What changes with age
Older men show a flatter curve — the morning peak is less pronounced, which is part of why fatigue and morning libido fade with age.
Frequently asked questions
- Best time to test testosterone?
- Between 7 and 10 AM, fasted ideally, within two hours of waking.
- Why does my afternoon T look low?
- Normal diurnal drop. Compare like with like — always morning to morning.
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