RecruitingPhase 4

L-Citrulline and Tadalafil for Mild to Moderate Erectile Dysfunction

Egypt133 participantsStarted 2026-06-08

Plain-language summary

Erectile dysfunction is a common male sexual health problem that may affect quality of life and sexual relationships. Tadalafil 5 mg once daily is an established oral treatment for erectile dysfunction. L-citrulline is an oral nitric oxide pathway supplement that may improve erectile function by increasing L-arginine availability. This randomized trial will compare three oral treatment regimens in men with mild to moderate erectile dysfunction: L-citrulline 1500 mg/day, tadalafil 5 mg/day, and the combination of L-citrulline 1500 mg/day plus tadalafil 5 mg/day. Participants will receive treatment for 12 weeks and will be followed at baseline, week 4, week 8, and week 12. The primary outcome will be the change in the International Index of Erectile Function-Erectile Function domain score from baseline to 12 weeks. Secondary outcomes will include changes in IIEF-5/SHIM score, Erection Hardness Score, SEP diary outcomes, treatment adherence, adverse events, and treatment discontinuation.

Who can participate

Age range

30 Years – 70 Years

Sex

MALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Male patients aged 30 to 70 years. * Erectile dysfunction for at least 3 months. * Mild to moderate erectile dysfunction, defined by International Index of Erectile Function-Erectile Function domain score from 11 to 25. * Stable sexual relationship during the study period. * Willingness to attempt sexual activity during the study period. * Ability to complete study questionnaires and attend follow-up visits. * Written informed consent. Exclusion Criteria: * Severe erectile dysfunction, defined by International Index of Erectile Function-Erectile Function domain score of 10 or less. * Current nitrate or nicorandil use. * Contraindication or hypersensitivity to tadalafil or L-citrulline. * Unstable cardiovascular disease, unstable angina, recent myocardial infarction or stroke, uncontrolled hypertension, or high-risk arrhythmia. * Severe hepatic impairment. * Severe renal impairment. * Untreated hypogonadism requiring hormonal treatment. * Hyperprolactinemia or uncontrolled endocrine disorder. * Major neurogenic erectile dysfunction, spinal cord injury, or previous radical pelvic surgery causing severe erectile dysfunction. * Significant Peyronie's disease preventing intercourse. * Active major psychiatric illness impairing reliable assessment. * Use of phosphodiesterase type 5 inhibitors, intracavernosal injection therapy, vacuum device therapy, testosterone therapy, L-arginine, L-citrulline, or erectile dysfunction nutraceuticals during the washout pe…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Change in International Index of Erectile Function-Erectile Function Domain Score

Timeframe: Baseline to 12 weeks

Trial details

NCT IDNCT07642505

SponsorBeni-Suef University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-11

Contact for this trial

Hany F Badawy, MD

+201149525028 HANYFATHY86@GMAIL.COM

View on ClinicalTrials.gov More Erectile Dysfunction trials