Evaluate the Pharmacokinetics and Gonadotropin Suppression of Nestorone®-Testosterone (NES/T) Combination Gel in Men

Inclusion Criteria: 1. Male volunteers in good health as confirmed by physical examination, medical history, and clinical laboratory tests of blood and urine at the time of screening; 2. 18 to 50 years of age; 3. BMI \< 33 calculated as weight in Kg/(height in cm)2; 4. No history of hormonal therapy use in the last six months prior to the first screening visit; 5. Subject will agree to use a recognized effective method of contraception with his partner (i.e. at a minimum, condom for the male partner and an effective contraception for the female partner) during the course of the study treatment and recovery phase; 6. In the opinion of the investigator, subject is able to comply with the protocol, understand and sign an informed consent and HIPAA form; 7. Does not meet any of the exclusion criteria. 8. Sperm concentration ≥ 15 million sperm per milliliter ejaculate. Exclusion Criteria: 1. Men participating in another clinical trial involving an investigational drug within the last 30 days prior to the first screening visit; 2. Men not living in the catchment's area of the clinic or within a reasonable distance from the site; 3. Clinically significant abnormal physical findings at screening; 4. Elevated PSA (levels ≥ 4 ng/mL), according to local laboratory normal values; 5. Abnormal serum chemistry values, according to local laboratory normal values that indicate liver or kidney dysfunction or that may be considered clinically significant; 6. Use of androgens or body building substances within 6 months before first screening visit; 7. Diastolic blood pressure (DBP) \> 80 and/or Systolic (SBP) \> 130 mm Hg; 8. EKG abnormal and clinically significant and QTC level longer than 450msec; 9. History of hypertension, including hypertension controlled with treatment; 10. Known history of primary testicular disease or disorders of the hypothalamic-pituitary axis; 11. Known hypersensitivity to progestins or androgen; 12. Family or personal history of venous thromboembolism; 13. Benign or malignant liver tumors; active liver disease; 14. Known history of reproductive dysfunction including vasectomy or infertility; 15. Known history of cardiovascular, renal, hepatic or prostatic disease; 16. A serious systemic disease such as diabetes mellitus or morbid obesity (body weight greater than 120% of ideal body weight or BMI limitation as above); 17. Known or suspected alcoholism or drug abuse that may affect metabolism/transformation of steroid hormones and study treatment compliance; 18. Known dermatitis or severe skin disorder; 19. Moderate or severe depression as determined by PHQ-9 score \>15; 20. Partner is known to be pregnant; 21. Known or suspected breast or prostate cancer; 22. Allergic to any ingredient in testosterone/nestorone gel, including alcohol; 23. Known history of untreated sleep apnea; 24. International Prostate Symptom Score (IPSS) greater than or equal to 15.