A, Serum T levels (mean ± SE) over 24 hours during the inpatient day (visit C) in the T gel (closed circles) and the placebo gel (open circles) groups. B, Serum T levels over 24 hours during the inpatient day (visit C) in representative participants with a low (fluctuation index 23%, closed circles) and high (fluctuation index 147%, open circles) fluctuation index in the T gel group and in another participant with a low (fluctuation index 21%, closed squares) and high (fluctuation index 103%, open squares) fluctuation index in the placebo group.