Patient case (clinical description): A 19-year-old male came to clinic with some sexual concern.  He recently engaged in a relationship and is worried about the satisfaction of his girlfriend. He has a "baby face" according to his girlfriend's statement and he is not as muscular as his classmates.  On physical examination, there is some pubic hair and poorly developed secondary sexual characteristics. He is unable to detect coffee smell during the examination, but the visual acuity is normal. Ultrasound reveals the testes volume of 1-2 ml. The hormonal evaluation showed serum testosterone level of 65 ng/dL with low levels of GnRH.

Patient's own account: I'm 19 years old guy and I just went to see a doctor at the clinic after I just got with my girlfriend. I'm kinda worried because she thinks that I have a baby face and to be honest, I'm way less muscular than my classmates. I don't have much hair down there, and yes, I don't have that macho look. The doctor made me smell some coffee and I couldn't smell anything special. I also had some eyesight checkups and the doctor told me everything was normal. I got my test results back and it says: testes volume is 1-2 ml and serum testosterone level of 65 ng/dL with low GnRH levels.

Clinical trial: Neuroendocrine Dysfunction in Traumatic Brain Injury: Effects of Testosterone Therapy

Eligibility criteria:
Inclusion Criteria:

          1. History of TBI as defined as "damage to brain tissue caused by an external mechanical
             force as evidenced by loss of consciousness or post traumatic amnesia (PTA) due to
             brain trauma or by objective neurological findings that can be reasonably attributed
             to TBI on physical examination or mental status examination;"82

          2. Moderate to severe TBI as indicated by a Glasgow Coma Scale (GCS) score of less than
             or equal to 12 at emergency department admission, or post traumatic amnesia (PTA) of
             greater than or equal to seven days post-injury, or radiographic evidence of
             intracranial injury;

          3. Continuously hospitalized from time of injury until admission for rehabilitation;

          4. Enrolled in study within 6 months of TBI;

          5. Receiving inpatient rehabilitation for TBI at Craig Hospital;

          6. Males between the ages of 16 to 65 (inclusive);

          7. Approval by attending physician;

          8. Testosterone level below the assay normal range;

          9. Consent to study participation

             Exclusion Criteria:

         10. History of any conditions that would prohibit testing contained in the NIH toolbox;

         11. Non-English or non-Spanish speaking (to the extent that would limit the ability to
             complete study measures);

         12. History of prior psychiatric illness requiring hospitalization;

         13. Prior testosterone therapy;

         14. History of or current or suspected hormonally dependent cancer , including carcinoma
             of the breast or prostate cancer;

         15. Known hypersensitivity to any T gel ingredients including alcohol and soy products;

         16. Hematocrit (HCT) greater than 55% (normal range in Colorado is up to 52) or
             transaminase elevation >4x upper limit of the normal range.

         17. Abnormal finding on digital rectal examination such as nodule, asymmetry, or
             induration (Does not include enlarged prostate or abnormal rectal tone)

         18. PSA>4.0

         19. BMI <16 or >40kg/m2

         20. History of untreated prolactinoma

         21. History of severe heart failure or uncontrolled medical problem that would interfere
             with the participant's safety in the study as determined by the investigator.
Male
No healthy subjects accepted to join the trial.
Subject must be at least 16 Years old.
Subject must be at most 65 Years

Eligibility (NLI label): Contradiction