The relationship between libido and testosterone levels in aging men

J Clin Endocrinol Metab. 2006 Jul;91(7):2509-13. doi: 10.1210/jc.2005-2508. Epub 2006 May 2.


Context: Although it is known that serum testosterone (T) concentrations are related to libido, the strength of that relationship in community-dwelling men has not yet been determined.

Objective: Our objective was to assess the strength and significance of the association between aging men's self-reports of libido and serum T concentrations.

Design: Our study was a community-based evaluation of men's health and aging, including three data collection waves: baseline (T1, 1987-1989) and follow-ups (T2, 1995-1997; T3, 2002-2004). Libido was measured on a 14-point scale assessing self-reported frequency of desire and thoughts/fantasies; low libido was defined as a score of less than 7 of 14.

Setting: We conducted an epidemiological study in greater Boston, Massachusetts.

Participants: There were 1632 men aged 40-70 yr at baseline, with follow-up on 922 (56%) at 9 yr (T2) and 623 (38%) at 15 yr (T3).

Main outcome measures: We assessed total and calculated bioavailable T .

Results: Three hundred eighteen (19%) subjects reported low libido at baseline. Libido and T displayed a significant association. However, the difference in mean T levels between those subjects with low libido and those without was small; analyses indicated a 3.4 ng/dl (0.12 nmol/liter) increase in total T per unit increase in libido. Subjects reporting low libido exhibited an increased but modest probability of exhibiting low T. Dividing T concentrations by the number of androgen receptor gene cytosine, adenine, guanine repeats did not enhance associations.

Conclusions: Libido and T concentrations are strongly related at the population level. However, the value of individual patient reports of reduced libido as indicators of low T levels is open to question.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenine
  • Adult
  • Aged
  • Aging / blood*
  • Cytosine
  • Follow-Up Studies
  • Guanine
  • Humans
  • Libido / physiology*
  • Longitudinal Studies
  • Luteinizing Hormone / blood
  • Male
  • Middle Aged
  • Receptors, Androgen / genetics
  • Repetitive Sequences, Nucleic Acid
  • Testosterone / blood*


  • Receptors, Androgen
  • Testosterone
  • Guanine
  • Cytosine
  • Luteinizing Hormone
  • Adenine