Inclusion Criteria:  Voluntarily sign and date the study consent form(s) which have been approved by an Institutional Review Board (IRB). Written consent must be obtained prior to the initiation of any study procedures. Males between 18 and 65 years of age. Documented diagnosis of testosterone deficiency. Prior treatment with testosterone therapy at the time of enrollment with adequate control of low testosterone symptoms. Serum total testosterone < 300 ng/dL on 2 measurements prior to the initiation of testosterone therapy. Patients must have completed an adequate washout period following prior testosterone therapy (4 weeks for gels and injection based therapies and 16 weeks for subcutaneous pellets). Judged to be in good general health as determined by the principal investigator based upon the results of a medical history, physical examination, vital signs, laboratory profile and a 12-lead electrocardiogram (ECG).  Exclusion Criteria:  History of significant sensitivity or allergy to androgens or product excipients. Clinically significant findings in the pre-study examinations including abnormal breast examination requiring follow-up or abnormal ECG. Abnormal prostate digital rectal examination (DRE) with palpable nodule(s) or International Prostate Symptom Score (I-PSS) score > 19 points. Body mass index (BMI) ≥ 40 kg/m2.  Clinically significant abnormal laboratory value, in the opinion of the investigator, in serum chemistry, hematology, or urinalysis including but not limited to:  Baseline hemoglobin > 16 g/dL Hematocrit < 35% or > 50% Poorly controlled blood pressure as defined by Systolic Blood Pressure (SBP) >150 or Diastolic Blood Pressure (DBP) > 90 on two separate measurements Concurrent use of any prohibited medications that can affect testosterone levels or metabolism. History of seizures or convulsions, including febrile, alcohol or drug withdrawal seizures. History of any clinically significant illness, infection, or surgical procedure within 4 weeks prior to study drug administration. History of stroke or myocardial infarction within the past 5 years. History of, or current or suspected, prostate or breast cancer. History of, or current or suspected, pituitary abnormality. History of diagnosed, severe, untreated, obstructive sleep apnea. History of abuse of alcohol or any drug substance in the opinion of the investigator within the previous 2 years. Receipt of any investigational product within 4 weeks or within 5 half-lives prior to the start of treatment. Inability to understand and provide written informed consent for the study. Considered by the investigator or the sponsor-designated physician, for any reason, that the subject is an unsuitable candidate to receive Jatenzo