Natesto Spermatogenesis Reboot

Inclusion Criteria: * Male between 18 and 64 years of age, with documented onset of testosterone induced hypogonadism with impaired semen parameters who are attempting to achieve a successful pregnancy. * Documented diagnosis of primary hypogonadism (congenital or acquired) or hypogonadotropic hypogonadism (congenital or acquired). * Serum total testosterone \< 350 ng/dL based on 2 consecutive blood samples obtained 1-4 weeks apart between 6 and 10 AM following an appropriate washout of current androgen replacement therapy; with clinical symptoms of hypogonadism such as diminished energy and sexual function; and/or a decreased sperm count (\<20 million sperm/mL semen). * Discontinued current testosterone replacement treatment and completed a washout of 4 weeks following androgen treatment (excluding Testopel TM). Washout must be completed prior to collection of baseline serum testosterone samples to determine study eligibility. * 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, and laboratory profile. Exclusion Criteria: * History of significant sensitivity or allergy to androgens, castor oil or product excipients. * Clinically significant findings in the pre-study examinations including abnormal breast examination requiring follow-up. * Abnormal prostate digital rectal examination (DRE) with palpable nodule(s) or I-PSS score greater than 19 points. * Body mass index (BMI) equal to or greater than or equal to 40 kg/m2. * History of vasectomy. * Clinically significant abnormal laboratory value, in the opinion of the investigator, in serum chemistry, hematology, or urinalysis including but not limited to: 1. Baseline hemoglobin greater than 16 g/dL 2. Hematocrit less than 35% or greater than 50% 3. PSA greater than 4 ng/mL and age greater than 40 * 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 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. * History of nasal disorders such as nasal polyps; nasal septal perforation; nasal surgery; nasal trauma resulting in nasal fracture within the previous 6 months or nasal fracture that caused a deviated anterior nasal septum; sinus surgery or sinus disease * Donation or loss of 550 mL or more blood volume (including plasmapheresis) or receipt of a transfusion of any blood product within 12 weeks prior to the start of treatment. * Inadequate venous access for collection of serial blood samples required for pharmacokinetic profiles. * 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 Natesto.