Clinical Research Directory

Inclusion Criteria: * Male adults 21 to 65 years of age, inclusive * Documented history of erectile dysfunction for at least 6 months, as determined by the investigator * In a stable sexual relationship and willing to attempt sexual activity as required by study procedures, if applicable * Medically stable based on medical history, physical examination, vital signs, 12-lead ECG, and clinical laboratory evaluations, in the opinion of the investigator * Able, in the investigator's judgment, to safely consume moderate amounts of alcohol as defined in the protocol * Willing to abstain from alcohol outside of protocol-specified intake during the study * Able to understand and provide written informed consent before any study-specific procedures are performed * Willing and able to comply with all study procedures, including dosing, washout periods, pharmacokinetic sampling, onset assessments, and safety monitoring Exclusion Criteria: * Known hypersensitivity or contraindication to sildenafil, other PDE5 inhibitors, alcohol, or any component of the Hezkue® formulation * Use of nitrates, nitric oxide donors, guanylate cyclase stimulators (such as riociguat), or other prohibited medications within a protocol-defined period * Clinically significant cardiovascular disease, including coronary artery disease, heart failure, clinically important arrhythmias, recent stroke, or uncontrolled hypertension or hypotension * Resting blood pressure or heart rate outside protocol-defined acceptable ranges at screening or baseline, in the opinion of the investigator * Significant hepatic, renal, neurologic, psychiatric, endocrine, hematologic, or respiratory disease that could increase risk or interfere with study assessments * History of syncope, significant orthostatic hypotension, or other conditions that may be worsened by sildenafil or alcohol * History of alcohol use disorder, binge drinking, or other substance use disorder, as determined by the investigator * Positive urine drug screen or positive alcohol test at screening or admission (outside protocol-specified alcohol administration) * Use of prescription or over-the-counter medications, herbal products, or dietary supplements within 14 days before first dosing unless approved by the investigator * Positive test for hepatitis B surface antigen, hepatitis C antibody, or HIV * Participation in another clinical study or receipt of an investigational product within 30 days or 5 half-lives, whichever is longer * Donation of 450 mL or more of blood, or significant blood loss, within 8 weeks before first dosing * Any condition or circumstance that, in the opinion of the investigator, would make the participant unsuitable or interfere with study conduct or interpretation