Sleep and testosterone. Is testosterone higher or lower when you are sleeping?

T Peaks in Early AM. Testosterone (t) waxes & wanes in a diurnal pattern that peaks in the early morning (accounting somewhat for our morning erections) and reaches its nadir (trough or low point) in the afternoon. That's why the endocrine society recommends checking your t on two separate mornings before arriving at a diagnosis of hypogonadism or low t.