[URL unfurl="true"]https://www.excelmale.com/forum/threads/reference-intervals-for-free-testosterone-in-adult-men-measured-using-a-standardized-equilibrium-dialysis-procedure.26279/[/URL]
*In healthy nonobese men, 19 years or older, the 2.5th, 10th, 25th, 50th, 75th, 90th and 97.5th percentile values for absolute free testosterone were 66, 91, 116, 141, 190, 240, and 309 pg/mL, respectively (Table 3). To convert standard units (pg/mL) to SI units (pmol/L), please divide the concentrations in pg/mL by 0.2885. In the subset of men, 19 to 39 years, the corresponding 2.5 th, 10th, 25th, 50th, 75th, 90th and 97.5th percentile values for absolute free testosterone were 120, 128, 149, 190, 228, 274, and 368 pg/mL. By convention, the 2.5th percentile of the reference sample defines the lower limit of the reference range and the 97.5th percentile value defines the upper limit (46,47). By this convention, the normal range in the reference sample of men 19 to 39 years is 120 to 368 pg/mL (415 to 1274 pmol/L) and, in all men, the range is 66 to 309 pg/mL [229 to 1072 pmol/L], respectively
*These reference ranges, generated in a reference sample of healthy men, should not be applied to other assays in other laboratories without appropriate cross-calibration of assays. Differences in study populations, time of sample collection, and testosterone assays can contribute to the differences in reference ranges. The adoption of a standardized procedure for measuring free testosterone and cross-calibration of the testosterone assays against an accuracy-based benchmark such as the CDC's HoST program will facilitate the application of these reference ranges across laboratories
