| NCT Number | Conditions | Interventions | Sponsor/Collaborators | Phases | Start Date | Last Updated |
| NCT00123162 | Dysmenorrhea | Drug: Sildenafil Citrate|Drug: Placebo | Milton S. Hershey Medical Center|National Institutes of Health (NIH) | Phase 1|Phase 2 | 2007-05-01 | 2015-11-18 |
| NCT01321489 | Erectile Dysfunction | Drug: Sildenafil Citrate 20mg Tablet Sublingual|Drug: Viagra 50mg tablet Coated | Laboratrio Teuto Brasileiro S/A | Phase 3 | 2011-09-01 | 2011-03-22 |
| NCT00781508 | Heart Failure|Left Ventricular Dysfunction | Drug: sildenafil|Other: Placebo | MetroHealth Medical Center|National Center for Research Resources (NCRR) | Phase 4 | 2006-12-01 | 2014-06-23 |
| NCT01668446 | Endometrial Preparation|Frozen Embryo Transfer | Drug: Sildenafil|Drug: estradiol valerat | farzaneh hojjat|Razieh dehghani firouzabadi|Robab davar|Shahid Sadoughi University of Medical Sciences and Health Services | Phase 4 | 2009-09-01 | 2012-09-11 |
| NCT01347008 | Scleroderma, Systemic|Scleroderma, Diffuse|Scleroderma, Limited|Raynaud Phenomenon | Drug: Sildenafil citrate|Drug: Placebo (Sugar pill) | Federal University of So Paulo|Fundao de Amparo Pesquisa do Estado de So Paulo | Phase 3 | 2011-04-01 | 2016-10-12 |
| NCT01889966 | Pulmonary Hypertension Associated With Connective Tissue Disease | Drug: Sildenafil | Kerckhoff Heart Center|Pfizer | Phase 4 | 2013-04-01 | 2015-04-26 |
| NCT02136329 | Acute Kidney Injury | Drug: Sildenafil | University of Leicester|British Heart Foundation | Phase 1 | 2013-06-01 | 2015-06-12 |
| NCT00199563 | Impotence | Drug: Viagra | Lawson Health Research Institute | Phase 4 | 2004-08-01 | 2013-01-24 |
| NCT02845388 | Infertility | Drug: Sildenafil citrate|Drug: estradiol valerate | Omar Ahmed El Sayed Saad|Ain Shams Maternity Hospital | Phase 2 | 2015-09-01 | 2016-07-26 |
| NCT01247805 | Pulmonary Arterial Hypertention | Drug: sildenafil citrate|Drug: Sildenafil citrate|Drug: sildenafil citrate | Pfizer | Phase 1 | 2011-01-01 | 2011-02-10 |
| NCT02466802 | Solid Tumor | Drug: Regorafenib|Drug: Sildenafil Citrate | Virginia Commonwealth University|Bayer | Phase 1 | 2015-07-01 | 2017-03-02 |
| NCT01670136 | Persistent Pulmonary Hypertension of the Newborn | Drug: 1 dose of sildenafil | University of North Carolina, Chapel Hill|Duke University|Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)|The EMMES Corporation | Phase 1 | 2013-02-01 | 2016-11-01 |
| NCT02372487 | Pregnancy Complication | Drug: sildenafil citrate|Dietary Supplement: fluid therapy | Al Hayat National Hospital|Menoufia University | | 2015-03-01 | 2016-02-02 |
| NCT00165295 | Waldenstrom's Macroglobulinemia | Drug: Sildenafil citrate (Viagra) | Dana-Farber Cancer Institute|Beth Israel Deaconess Medical Center | Phase 2 | 2005-09-01 | 2011-06-23 |
| NCT01365585 | Pulmonary Arterial Hypertension | Drug: sildenafil citrate | Pfizer | | 2011-07-01 | 2013-01-08 |
| NCT01830790 | Age-related Macular Degeneration | Drug: Sildenafil citrate | Duke University | Phase 2 | 2013-03-01 | 2015-05-27 |
| NCT00527995 | Type 2 Diabetes Mellitus|Endothelial Dysfunction | Drug: Sildenafil | Ruhr University of Bochum | Phase 3 | 2001-08-01 | 2007-09-10 |
| NCT00454207 | Pulmonary Hypertension | Drug: sildenafil citrate (UK-92,480) | Pfizer | Phase 3 | 2007-04-01 | 2013-08-19 |
| NCT01054001 | Prostate Cancer | Drug: sildenafil 100mg | Seoul National University Bundang Hospital|Pfizer | | 2010-06-01 | 2011-08-18 |
| NCT01954524 | Cirrhosis | Drug: IV bolus injection of Sildenafil | University of Maryland | Phase 1 | 2014-05-01 | 2016-10-30 |
