Impact of Estradiol Addback


About this study

Repletion of testosterone (T) in older men drives Growth Hormone secretion after its aromatization to estradiol (E2) by potentiating endogenous GH drive.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • 60 healthy men (ages 60 to 80 y);
  • BMI 18-30 kg/m2
  • Community dwelling; and voluntarily consenting

Exclusion Criteria:

  • Recent use of psychotropic or neuroactive drugs (within five biological half-live);
  • Obesity (outside weight range above);
  • Laboratory test results not deemed physician acceptable, cholesterol >250, triglycerides > 300, BUN >30 or creatinine > 1.5 mg/dL, liver functions tests twice upper limit of normal, electrolyte abnormality, anemia; hemoglobin <12.0 gm/dL
  • Drug or alcohol abuse, psychosis, depression, mania or severe anxiety;
  • Acute or chronic organ-system disease;
  • Endocrinopathy, other than primary thyroidal failure receiving replacement; untreated osteoporosis
  • Nightshift work or recent transmeridian travel (exceeding 3 time zones within 7 days of admission);
  • Acute weight change (loss or gain of > 2 kg in 6 weeks);
  • Allergy to peanut oil (used in some injectable Te preparations)
  • Unwillingness to provide written informed consent.
  • PSA > 4.0 ng/mL
  • History or suspicion of prostatic disease (elevated PSA, indeterminate nodule or mass, obstructive uropathy.
  • History of carcinoma (excluding localized basal cell carcinoma removed or surgically treated with no recurrence.
  • History of thrombotic arterial disease (stroke, TIA, MI, angina) or deep vein thrombophlebitis.
  • History of CHF, cardiac arrhythmias, congential QT prolongation, and medications used to treat cardiac arrhythmias
  • Gynecomastia > 2 cm, untreated
  • Untreated gallbladder disease
  • History of smoking greater than one ppd.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Johannes Veldhuis, M.D.

Closed for enrollment

More information


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Additional contact information

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Phone: 800-664-4542 (toll-free)

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