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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
Free T Lab Ranges/Units Confusion
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<blockquote data-quote="madman" data-source="post: 191930" data-attributes="member: 13851"><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/are-labcorp-and-quest-testosterone-lab-ranges-equivalent-even-though-theyre-different.21670/[/URL]</p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/truttm.22027/[/URL]</p><p></p><p></p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/allosterically-coupled-multi-site-binding-of-t-to-human-serum-albumin.22102/#post-190020[/URL]</p><p></p><p><strong>Lack of Standardization of Free Testosterone Measurement Methods and Unavailability of Harmonized Reference Ranges for Free Testosterone</strong></p><p></p><p><em>Le et al. (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">222</a>) surveyed 120 academic and community laboratories in the United States to characterize the distribution of assays and the associated reference values for free testosterone. In all, 84% of the surveyed laboratories sent their samples for free testosterone measurement to larger centralized reference laboratories (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">222</a>). These large commercial laboratories offered a variety of methods, including ultracentrifugation, radioimmunoassay, and calculation-based algorithms, as well as equilibrium dialysis (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">222</a>). Many clinical laboratories used calculated free testosterone based on published linear equations (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">3</a>).<strong> <span style="color: rgb(184, 49, 47)"><u>The laboratories reported wide variations in the reference ranges. Only 30 of the laboratories surveyed would confirm that validation studies had been performed, and the authors advised that reference ranges provided by manufacturers and laboratories should be interpreted with caution</u>.</span></strong></em></p><p><em><strong><span style="color: rgb(184, 49, 47)"></span></strong></em></p><p><em><strong><span style="color: rgb(184, 49, 47)"><u>In a survey of 12 academic laboratories, 12 community medical laboratories, and one national laboratory, Lazarou et al. (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">223</a>) found 17 and 13 different sets of reference values for total and free testosterone, respectively, which were established largely without clinical considerations</u>.</span> </strong>Recently, Bhasin et al. (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">224</a>) reported reference ranges for calculated free testosterone concentrations in a large, rigorously collected sample of community-dwelling men. In healthy young men of the Framingham Heart Study who were 19 to 40 years of age, the lower limit of the normal range, defined as the 2.5th percentile of calculated free testosterone, was 70 pg/mL (242.7 pmol/L) (<a href="https://www.excelmale.com/forum/javascript%3A;" target="_blank">198</a>).</em></p><p></p><p></p><p></p><p>post<span style="color: rgb(184, 49, 47)">#9</span></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/about-1-year-off-of-t-labs.22189/#post-190837[/URL]</p><p>[ATTACH=full]11970[/ATTACH]</p><p></p><p></p><p></p><p>post <span style="color: rgb(184, 49, 47)">#6/7</span></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/very-confused-lab-results-advice-insights.22331/[/URL]</p><p>[ATTACH=full]11971[/ATTACH]</p><p>[ATTACH=full]11972[/ATTACH]</p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p>post<span style="color: rgb(184, 49, 47)">#9</span></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/about-1-year-off-of-t-labs.22189/#post-190837[/URL]</p><p></p><p>If you are going to base your FT level on the cFTZ then 18 ng/dL would be far from low as 16.4-31.4 ng/dL would be considered a healthy range.</p><p></p><p>Some would consider 18 ng/dL sub-par as many tend to do better running higher levels 30 ng/dL.</p><p></p><p>FT level of 5-9 ng/dL would be considered low and many can suffer from low-t symptoms at levels slightly higher.</p><p></p><p>If you go by the cFTV then your FT would be considered low.</p><p></p><p></p><p></p><p></p><p>I would still look into having your FT tested using the most accurate assays Equilibrium Dialysis or Ultrafiltration.</p><p></p><p>Quest</p><p>1 <a href="https://www.discountedlabs.com/hematocrit-total-and-free-testosterone-1500-ng-dl" target="_blank">Testosterone, Total and Free (NO Upper Limit) plus Hematocrit</a></p><p></p><p>2 <a href="https://www.discountedlabs.com/testosterone-free-dialysis-and-total-ls-ms-ms" target="_blank">Testosterone, Total, LC/MS and Free (Equilibrium Ultrafiltration)</a></p><p></p><p>Labcorp</p><p>3 <a href="https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences" target="_blank">500726: Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) | LabCorp</a> (ENDOCRINE SCIENCES) <u>reference range 5.2-28.0 ng/dL</u></p><p></p><p>4 <a href="https://www.labcorp.com/tests/070038/testosterone-free-equilibrium-ultrafiltration-with-total-testosterone-lc-ms-ms" target="_blank">070038: Testosterone, Free, Equilibrium Ultrafiltration With Total Testosterone, LC/MS-MS | LabCorp</a> <u>reference range 5.0-21.0 ng/dL</u></p><p></p><p></p><p></p><p><span style="color: rgb(0, 0, 0)"><strong>*</strong></span><span style="color: rgb(26, 188, 156)"><strong><u>Any of these will suffice but I prefer #3 that has a reference range of 5.2-28.0 ng/dL</u>.</strong></span></p><p></p><p>Most men will do well having an FT in the 20-30 ng/dL range and many will have no issues even with a FT 16 ng/dL!</p></blockquote><p></p>
[QUOTE="madman, post: 191930, member: 13851"] [URL unfurl="true"]https://www.excelmale.com/forum/threads/are-labcorp-and-quest-testosterone-lab-ranges-equivalent-even-though-theyre-different.21670/[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/truttm.22027/[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/allosterically-coupled-multi-site-binding-of-t-to-human-serum-albumin.22102/#post-190020[/URL] [B]Lack of Standardization of Free Testosterone Measurement Methods and Unavailability of Harmonized Reference Ranges for Free Testosterone[/B] [I]Le et al. ([URL='https://www.excelmale.com/forum/javascript%3A;']222[/URL]) surveyed 120 academic and community laboratories in the United States to characterize the distribution of assays and the associated reference values for free testosterone. In all, 84% of the surveyed laboratories sent their samples for free testosterone measurement to larger centralized reference laboratories ([URL='https://www.excelmale.com/forum/javascript%3A;']222[/URL]). These large commercial laboratories offered a variety of methods, including ultracentrifugation, radioimmunoassay, and calculation-based algorithms, as well as equilibrium dialysis ([URL='https://www.excelmale.com/forum/javascript%3A;']222[/URL]). Many clinical laboratories used calculated free testosterone based on published linear equations ([URL='https://www.excelmale.com/forum/javascript%3A;']3[/URL]).[B] [COLOR=rgb(184, 49, 47)][U]The laboratories reported wide variations in the reference ranges. Only 30 of the laboratories surveyed would confirm that validation studies had been performed, and the authors advised that reference ranges provided by manufacturers and laboratories should be interpreted with caution[/U]. [U]In a survey of 12 academic laboratories, 12 community medical laboratories, and one national laboratory, Lazarou et al. ([URL='https://www.excelmale.com/forum/javascript%3A;']223[/URL]) found 17 and 13 different sets of reference values for total and free testosterone, respectively, which were established largely without clinical considerations[/U].[/COLOR] [/B]Recently, Bhasin et al. ([URL='https://www.excelmale.com/forum/javascript%3A;']224[/URL]) reported reference ranges for calculated free testosterone concentrations in a large, rigorously collected sample of community-dwelling men. In healthy young men of the Framingham Heart Study who were 19 to 40 years of age, the lower limit of the normal range, defined as the 2.5th percentile of calculated free testosterone, was 70 pg/mL (242.7 pmol/L) ([URL='https://www.excelmale.com/forum/javascript%3A;']198[/URL]).[/I] post[COLOR=rgb(184, 49, 47)]#9[/COLOR] [URL unfurl="true"]https://www.excelmale.com/forum/threads/about-1-year-off-of-t-labs.22189/#post-190837[/URL] [ATTACH type="full" alt="Screenshot (2864).png"]11970[/ATTACH] post [COLOR=rgb(184, 49, 47)]#6/7[/COLOR] [URL unfurl="true"]https://www.excelmale.com/forum/threads/very-confused-lab-results-advice-insights.22331/[/URL] [ATTACH type="full" alt="Screenshot (2865).png"]11971[/ATTACH] [ATTACH type="full" alt="Screenshot (2866).png"]11972[/ATTACH] post[COLOR=rgb(184, 49, 47)]#9[/COLOR] [URL unfurl="true"]https://www.excelmale.com/forum/threads/about-1-year-off-of-t-labs.22189/#post-190837[/URL] If you are going to base your FT level on the cFTZ then 18 ng/dL would be far from low as 16.4-31.4 ng/dL would be considered a healthy range. Some would consider 18 ng/dL sub-par as many tend to do better running higher levels 30 ng/dL. FT level of 5-9 ng/dL would be considered low and many can suffer from low-t symptoms at levels slightly higher. If you go by the cFTV then your FT would be considered low. I would still look into having your FT tested using the most accurate assays Equilibrium Dialysis or Ultrafiltration. Quest 1 [URL='https://www.discountedlabs.com/hematocrit-total-and-free-testosterone-1500-ng-dl']Testosterone, Total and Free (NO Upper Limit) plus Hematocrit[/URL] 2 [URL='https://www.discountedlabs.com/testosterone-free-dialysis-and-total-ls-ms-ms']Testosterone, Total, LC/MS and Free (Equilibrium Ultrafiltration)[/URL] Labcorp 3 [URL='https://www.labcorp.com/tests/500726/testosterone-free-mass-spectrometry-equilibrium-dialysis-endocrine-sciences']500726: Testosterone, Free, Mass Spectrometry/Equilibrium Dialysis (Endocrine Sciences) | LabCorp[/URL] (ENDOCRINE SCIENCES) [U]reference range 5.2-28.0 ng/dL[/U] 4 [URL='https://www.labcorp.com/tests/070038/testosterone-free-equilibrium-ultrafiltration-with-total-testosterone-lc-ms-ms']070038: Testosterone, Free, Equilibrium Ultrafiltration With Total Testosterone, LC/MS-MS | LabCorp[/URL] [U]reference range 5.0-21.0 ng/dL[/U] [COLOR=rgb(0, 0, 0)][B]*[/B][/COLOR][COLOR=rgb(26, 188, 156)][B][U]Any of these will suffice but I prefer #3 that has a reference range of 5.2-28.0 ng/dL[/U].[/B][/COLOR] Most men will do well having an FT in the 20-30 ng/dL range and many will have no issues even with a FT 16 ng/dL! [/QUOTE]
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Testosterone Replacement, Low T, HCG, & Beyond
Testosterone Basics & Questions
Free T Lab Ranges/Units Confusion
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