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Christian J. Cook, Blair T. Crewther, Liam P. Kilduff, Linda L. Agnew, Phillip Fourie, and Benjamin G. Serpell

dihydrotestosterone (DHT) as part of the androgenic pathway also exists. 1 , 16 DHT, although an androgenic hormone in its own right because of its production in the prostate, 17 is produced in males and females mostly from the rapid and irreversible reduction of free testosterone (FT) in peripheral tissues of the

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Darryn S. Willoughby, Colin Wilborn, Lemuel Taylor, and William Campbell

This study examined the effects of an aromatase-inhibiting nutritional supplement on serum steroid hormones, body composition, and clinical safety markers. Sixteen eugonadal young men ingested either Novedex XT™ or a placebo daily for 8 wk, followed by a 3-wk washout period. Body composition was assessed and blood and urine samples obtained at weeks 0, 4, 8, and 11. Data were analyzed by 2-way repeated-measures ANOVA. Novedex XT resulted in average increases of 283%, 625%, 566%, and 438% for total testosterone (P = 0.001), free testosterone (P = 0.001), dihydrotestosterone (P = 0.001), and the testosterone:estrogen ratio (P = 0.001), respectively, whereas fat mass decreased 3.5% (P = 0.026) during supplementation. No significant differences were observed in blood and urinary clinical safety markers or for any of the other serum hormones (P > 0.05). This study indicates that Novedex XT significantly increases serum androgen levels and decreases fat mass.

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Colin Wilborn, Lem Taylor, Chris Poole, Cliffa Foster, Darryn Willoughby, and Richard Kreider

The purpose of this study was to determine the effects of an alleged aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum (1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05). Significant Group × Time interaction effects occurred over the 8-wk period for percent body fat (AI: –1.77% ± 1.52%, PL: –0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: –2.10 ± 3.75 ng/ml; p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: –1.69 ± 3.94 ng/ml; p = .049). Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05). The authors concluded that 500 mg of daily AI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion.

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ZhiWei Liu, Ting Chen, Mingkang Shen, Kai Li, ChunJie Ma, Antonnette Ketlhoafetse, and XiangYun Liu

decreases in older adults, while its metabolites, such as dihydrotestosterone and estradiol (E 2 ), increase ( Rastrelli, Vignozzi, Corona, & Maggi, 2019 ). Liu, Liu, et al. ( 2019 ) established a mathematical model that predicts the association between E 2 /T ratio and the development of BPH in rats. An

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Tony Adebero, Brandon John McKinlay, Alexandros Theocharidis, Zach Root, Andrea R. Josse, Panagiota Klentrou, and Bareket Falk

with prednisolone, at 46.2% (other proteins <5%). The salivary testosterone assay kit has a 36.4% dihydrotestosterone and 21.02% 19-nortestosterone cross-reactivity (other proteins <2%), whereas the serum testosterone kit has a 2.03% cross-reactivity with dihydrotestosterone. All standards, controls

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Diogo V. Leal, Lee Taylor, and John Hough

testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study . Clin Endocrinol . 2012 ; 77 ( 5 ): 755 – 763 . doi:10.1111/j.1365-2265.2012.04432.x 10.1111/j.1365-2265.2012.04432.x 26. Kuoppasalmi K , Näveri H , Härkönen M

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Federico Donghi, Ermanno Rampinini, Andrea Bosio, Maurizio Fanchini, Domenico Carlomagno, and Nicola A. Maffiuletti

): 85 – 92 . PubMed ID: 20308978 20308978 31. Smith AA , Toone R , Peacock O , Drawer S , Stokes KA , Cook CJ . Dihydrotestosterone is elevated following sprint exercise in healthy young men . J Appl Physiol . 2013 ; 114 ( 10 ): 1435 – 1440 . doi:10.1152/japplphysiol.01419.2012 10

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Travis Anderson, Sandra J. Shultz, Nancy I. Williams, Ellen Casey, Zachary Kincaid, Jay L. Lieberman, and Laurie Wideman

. Nature, 325 , 813 – 816 . PubMed ID: 2434861 doi:10.1038/325813a0 10.1038/325813a0 Dehghan , F. , Muniandy , S. , Yusof , A. , & Salleh , N. ( 2014 ). Testosterone reduces knee passive range of motion and expression of relaxin receptor isoforms via 5α-dihydrotestosterone and androgen

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Bruno Marrier, Alexandre Durguerian, Julien Robineau, Mounir Chennaoui, Fabien Sauvet, Aurélie Servonnet, Julien Piscione, Bertrand Mathieu, Alexis Peeters, Mathieu Lacome, Jean-Benoit Morin, and Yann Le Meur

ID: 15705047 12. Guignard MM , Pesquies PC , Serrurier BD , Merino DB , Reinberg AE . Circadian rhythms in plasma levels of cortisol, dehydroepiandrosterone, delta 4-androstenedione, testosterone and dihydrotestosterone of healthy young men . Acta Endocrinol . 1980 ; 94 : 536 – 545