Scientific Support for Testosterone

Key points for Testosterone
Functions of Testosterone


  • Sex hormone
  • Receptors all over a male’s body
  • Involved in the making of protein and muscle formation
  • Helps manufacture bone
  • Improves oxygen uptake throughout the body
  • Helps control blood sugar
  • Helps regulate cholesterol
  • Helps maintain a powerful immune system
  • Aids in mental concentration
  • Improves mood
  • Helps protect the brain against Alzheimer’s disease

Testosterone and Alzheimer’s


  • Testosterone replacement prevents the production of beta amyloid precursor protein in men.

Gouras, G., et al., “Testosterone reduces neuronal secretion of Alzheimer’s beta-amyloid peptides,” Proc Natl Acad Sci U S A 2000; 97(3):1202-5.

Testosterone and CV (Cardio Vascular) Risk


  • The lower the free testosterone the more likely coronary artery disease
  • Testosterone improves exercise induced ST depression (finding on electrocardiogram)
  • Dilates coronary arteries
  • Low testosterone associated with Dyslipidemia (bad cholesterol)

Testosterone and CAD (Coronary Artery Disease)


  • Men with CAD had significantly lower total testosterone, free testosterone, and bioavailable testosterone.

English, K., et al., “Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms,” Eur. Heart Journ. 2000; 21(11):890-4.

Testosterone and Prostate Cancer


  • “There is no clinical evidence that the risk of either prostate cancer or BPH increases with transdermal testosterone replacement.”

Morley, J., et al., “Testosterone replacement and the physiologic aspects of aging in men,” Mayo Clin; Proc 2000; 75 (Suppl):S83-7. 

Testosterone and Insulin Resistance


  • Testosterone replacement decreases insulin resistance.
  • Supraphysiologic doses increase insulin resistance.
  • Low levels of testosterone play some role in the development of type 2 diabetes. (Stellato)
  • Hyperinsulinemia decreases testosterone and replacement decreases hyperinsulinemia.

Insulin and Sex Hormones


  • Estrogen, progesterone, DHEA, and thyroid hormones are all important for the regulation of glucose in the body.
  • Testosterone decreases blood glucose in a male. 


  • Stellato, R., et al., “Testosterone, sex hormone-binding globulin, and the development of type 2 diabetes in middle-aged men: prospective results from the Massachusetts male aging study,” Diabetes Care 2000; 23(4):490-4.
  • Rizza, R., et al., “Androgen effect on insulin action and glucose metabolism,” Mayo Clin Proc 2000 75(Suppl):S61-4. Pasquali, R., et al., “Effects of acute hyperinsulinemia on testosterone serum concentrations in adult obese and normal-weight men,” Metabolism 1997; 46(5):526-9.