This is a single-center study intended to evaluate prealbumin (transthyretin), a marker of anabolic metabolism, in men with androgen deficiency (Low-T). There is emerging evidence that prealbumin is an indicator of anabolic, versus catabolic, metabolism, and that lower levels may be associated with hypogonadism.

Inclusion Criteria:

• Provide responses to standard questionnaires administered to subjects
• Written Informed Consent obtained
• Male sex at birth
• ≥ 40 and ≤ 75 years of age
• Presentation to the clinic with symptoms suggestive of low testosterone such as loss of libido, erectile dysfunction, cognitive or mood disturbances, etc.
• Able and willing to provide blood specimens and follow study schedule
• A final diagnosis can be established (androgen deficient versus not androgen deficient)

Exclusion Criteria:

• Previous exposure to exogenous T, DHEA, clomiphen citrate, or other Selective Estrogen Receptor Modulators, or OTC or herbals (Treatment Naïve)
• Use of opioid medication within 3 months prior to enrollment
• Serious psychiatric disease or uncontrolled medical illness, as suspected from medical history or clinical examination
• Use of any sex hormones or steroidal anabolic drug supplements (OTC or prescribed)(Treatment Naïve)
• Incapable of giving informed consent or complying with protocol or unwilling to comply with protocol requirements
• Diagnosis of prolactinoma

Male sex at birth

Men between the ages of 40 and 75 presenting with signs/symptoms of low-T.