Human growth hormone is biosynthetic and has the exact same molecular structure as in the human body. It is responsible for growth, healing, immune function, increased muscle mass, minimizing body fat, controlling cholesterol, maintaining sexual energy, and increasing bone strength. It improves heart function and cognitive ability including memory, alertness, motivation, work capacity, speed of information processing and sociability. Growth hormone replacement at physiologic levels does not cause cancer. Growth hormone acts synergistically with testosterone in that their beneficial effects together are greater than either one alone.

Source: GENERAL MEDICAL COMMUNITY: www.wellsphere.com/general-medicine-article/human-growth-hormone-and-testosterone-by-candice-lane-m-d/367686;jsessionid=32EB1C89F22A637EEF8C67B53C767C31?query=Testosterone+Hormone

Testosterone and Growth Hormone Improve Body Composition and Muscle Performance in Older Men

Fred R. Sattler, Carmen Castaneda-Sceppa, Ellen F. Binder, E. Todd Schroeder, Ying Wang, Shalender Bhasin, Miwa Kawakubo, Yolanda Stewart, Kevin E. Yarasheski, Jagadish Ulloor, Patrick Colletti, Ronenn Roubenoff and Stanley P. Azen

Departments of Medicine (F.R.S., Y.S.), Preventive Medicine (Y.W., M.K., S.P.A.), and Radiology (P.C.), and Division of Biokinesiology (F.R.S., E.T.S.), University of Southern California, Los Angeles, California 90033; Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University (C.C.-S., R.R.), Boston, Massachusetts 02111; Department of Medicine (E.F.B., K.E.Y.), Washington University, St. Louis, Missouri 63110; and Section of Endocrinology, Diabetes, and Nutrition (S.B., J.U.), Boston University, Boston, Massachusetts 02215

Context: Impairments in the pituitary-gonadal axis with aging are associated with loss of muscle mass and function and accumulation of upper body fat.

Objectives: We tested the hypothesis that physiological supplementation with testosterone and GH together improves body composition and muscle performance in older men.

Design, Setting, and Participants: One hundred twenty-two community-dwelling men 70.8 ± 4.2 yr of age with body mass index of 27.4 ± 3.4 kg/m2, testosterone of 550 ng/dl or less, and IGF-I in lower adult tertile (167 ng/dl) were randomized to receive transdermal testosterone (5 or 10 g/d) during a Leydig cell clamp plus GH (0, 3, or 5 µg/kg • d) for 16 wk.

Main Outcome Measures: Body composition by dual-energy x-ray absorptiometry, muscle performance, and safety tests were conducted.

Results: Total lean body mass increased (1.0 ± 1.7 to 3.0 ± 2.2 kg) as did appendicular lean tissue (0.4 ± 1.4 to 1.5 ± 1.3 kg), whereas total fat mass decreased by 0.4 ± 0.9 to 2.3 ± 1.7 kg as did trunk fat (0.5 ± 0.9 to 1.5 ± 1.0 kg) across the six treatment groups and by dose levels for each parameter (P 0.0004 for linear trend). Composite maximum voluntary strength of upper and lower body muscles increased by 14 ± 34 to 35 ± 31% (P < 0.003 in the three highest dose groups) that correlated with changes in appendicular lean mass. Aerobic endurance increased in all six groups (average 96 ± 137sec longer). Systolic and diastolic blood pressure increased similarly in each group with mean increases of 12 ± 14 and 8 ± 8 mm Hg, respectively. Other predictable adverse events were modest and reversible.

Conclusions: Supplemental testosterone produced significant gains in total and appendicular lean mass, muscle strength, and aerobic endurance with significant reductions in whole-body and trunk fat. Outcomes appeared to be further enhanced with GH supplementation.

Source: Journal of Clinical Endocrinology & Metabolism: http://jcem.endojournals.org/cgi/content/abstract/94/6/1991