This study is examining the effects of growth hormone releasing hormone (GHRH) on mild cognitive impairment (MCI). GHRH will be given at a dose of 1mg/day for 10 weeks to subjects with MCI as well as healthy controls.

Subjects with MCI as well as healthy controls will be given GHRH at a dose of 1mg/day for 10 weeks.

This study is designed to investigate the effects of GHRH on the following things: 1) cognitive function as measured by our neuropsychologist with a series of short tests; 2) brain activity as measured by fMRI 3) lean and fat mass of your body as measured by DEXA; 4) physical function as measured by a walking test.

Inclusion Criteria:

• Age ≥ 55 to ≤ 85 years
• Ability to sign consent form (score ≥ on the Mini Mental State Examination, MMSE)
• MCI group: MMSE scores of 23 - 26
• Normal Control Group: MMSE scores of 27 - 30

Exclusion Criteria:

• Diabetes
• A neurologic condition other than MCI which might cause cognitive impairment
• Baseline serum IGF-1 concentration greater than the midrange for healthy young adults (300ng/ml)
• Presence of a pacemaker or metal implant
• Heart Failure
• Edema
• Active malignancy
• Carpal tunnel syndrome
• Disruption of the hypothalamic pituitary axis such that the pituitary is expected to be insensitive to growth hormone secretagogues such as GHRH
• Known allergy to tesamorelin or mannitol
• Pregnancy
• Significant heart, liver, kidney, blood or respiratory disease
• Active cancer
• Recent (within 6 months) treatment with anabolic steroids, GHRH or corticosteroids
• Alcohol or drug abuse
• MMSE < 23
• Less than 12 years of education
• Significant findings on screening tests, including but not limited to, blood counts, blood biochemistries, urinalysis, drug screening, HIV test, hepatitis panel, electrocardiogram
• Other medical conditions deemed exclusionary by the study investigators