Although soy contains phytoestrogens -- naturally occuring plant estrogens -- soyfoods and soy isoflavone supplements have no significant impact on male reproductive hormone levels in men, a new study published by the American Society for Reproductive Medicine finds. Continue reading…

The Use of a Sensitive Equilibrium Dialysis Method for the Measurement of Free Testosterone Levels in Healthy, Cycling Women and in Human Immunodeficiency Virus-Infected Women1 Indrani Sinha-Hikim, Stefan Arver, Gildon Beall, Ruoqing Shen, Mario Guerrero, Fred Sattler, Cecilia Shikuma, Jerald C. Continue reading…

Middle-Aged Men Secrete Less Testosterone at Night Than Young Healthy Men Rafael Luboshitzky, Zila Shen-Orr and Paula Herer Endocrine Institute, Haemek Medical Center (R.L.), Afula 18101, Israel; and Endocrine Laboratory, Rambam Medical Center (Z.S.-O.), and Sleep Research Center, Technion, Israel Institute of Technology (P. Continue reading…

Specific Linkages Among Luteinizing Hormone, Follicle-Stimulating Hormone, and Testosterone Release in the Peripheral Blood and Human Spermatic Vein: Evidence for Both Positive (Feed-Forward) and Negative (Feedback) Within-Axis Regulation1 C. Foresta, P. Bordon, M. Rossato, R. Mioni and J. D. Veldhuis Instuto di Semeiotica Medica, Universita Degli Studi Di Padova (C. Continue reading…

Pharmacokinetics of a Novel Testosterone Matrix Transdermal System in Healthy, Premenopausal Women and Women Infected with the Human Immunodeficiency Virus Marjan Javanbakht, Atam B. Singh, Norman A. Mazer, Gildon Beall, Indrani Sinha-Hikim, Ruoquen Shen and Shalender Bhasin Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Continue reading…

Metabolism of Orally Administered Androstenedione in Young Men Benjamin Z. Leder, Don H. Catlin, Christopher Longcope, Brian Ahrens, David A. Schoenfeld and Joel S. Finkelstein Endocrine Unit, Department of Medicine (B.Z.L., J.S.F.), and Department of Biostatistics (D.A.S.), Massachusetts General Hospital, Boston, Massachusetts 02114; Departments of Medicine and Obstetrics and Gynecology, University of Massachusetts Medical School (C. Continue reading…

Pharmacokinetics of a Transdermal Testosterone System in Men with End Stage Renal Disease Receiving Maintenance Hemodialysis and Healthy Hypogonadal Men Atam B. Singh, Keith Norris, Nishit Modi, Indrani Sinha-Hikim, Ruoquing Shen, Tina Davidson and Shalender Bhasin Divisions of Endocrinology, Metabolism, and Molecular Medicine (A. Continue reading…

Effects of Testosterone Replacement with a Nongenital, Transdermal System, Androderm, in Human Immunodeficiency Virus-Infected Men with Low Testosterone Levels1 Shalender Bhasin, Thomas W. Storer, Nancy Asbel-Sethi, Amy Kilbourne, Ron Hays, Indrani Sinha-Hikim, Ruoquing Shen, Stefan Arver and Gildon Beall Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Continue reading…

Testosterone Dose-Dependently Increases Maximal Voluntary Strength and Leg Power, but Does Not Affect Fatigability or Specific Tension Thomas W. Storer, Lynne Magliano, Linda Woodhouse, Martin L. Lee, Connie Dzekov, Jeanne Dzekov, Richard Casaburi and Shalender Bhasin Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Continue reading…