Phase 2 Efficacy Study of Sildenafil Products in Adult Men With Erectile Dysfunction

November 17, 2025 updated by: Aspargo Labs, Inc

A Phase 2 Open-Label Study to Evaluate the Efficacy, Safety, and Treatment Experience of Hezkue® and Hezkue Turbo® Compared With Select Commercially Available Sildenafil Products in Adult Men With Erectile Dysfunction (ED)

The goal of this clinical trial is to learn how different sildenafil-based erectile dysfunction (ED) treatments affect erectile function in adult men. The main questions it aims to answer are:

Does each assigned product improve erectile function over 12 weeks?

What safety or tolerability issues occur when these products are used on an on-demand basis?

Researchers will compare Hezkue® and Hezkue Turbo® with several commercially available sildenafil or sildenafil-plus-tadalafil products to see whether there are differences in effectiveness, treatment experience, or safety.

Participants will:

  • Use one assigned ED treatment on demand for 12 weeks
  • Complete electronic diaries and questionnaires about sexual-encounter outcomes and treatment satisfaction
  • Attend study visits for safety checks, laboratory tests, and assessments of erectile function

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This Phase 2, open-label, parallel-group clinical trial evaluates the real-world use of multiple sildenafil-based erectile dysfunction (ED) treatments, including two oral liquid formulations (Hezkue® and Hezkue Turbo®) and several commercially available tablet, chewable, or combination (sildenafil/tadalafil) products. The study is designed to characterize differences in erectile function outcomes, safety profiles, and patient-reported treatment experiences across these products when used on an on-demand basis.

The trial includes a screening period of up to 28 days, followed by 12 weeks of treatment with one assigned product. Participants will use electronic diaries and questionnaires to record sexual-encounter outcomes, timing of effects, treatment satisfaction, and other patient-reported measures. Safety evaluations include adverse event monitoring, vital signs, clinical laboratory assessments, and targeted cardiovascular, ophthalmologic, and otologic examinations.

The design reflects typical on-demand PDE5 inhibitor use and enables comparative assessment across distinct formulations and delivery systems (liquid spray, orodispersible/chewable, and standard tablets). Exploratory analyses will examine work productivity, activity impairment, healthcare utilization, and optional partner-reported measures to better understand the broader impact of ED treatment in daily life.

This description supplements, but does not repeat, information provided in the Brief Summary, Eligibility, or Outcome Measures sections.

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male, 18 to 70 years of age.

Documented diagnosis of erectile dysfunction (ED) for at least 3 months, confirmed by a clinician.

Baseline International Index of Erectile Function-Erectile Function (IIEF-EF) domain score ≤25.

Sexually active and attempting sexual intercourse at least 4 times per month during the 3 months prior to screening.

Willing and able to attempt sexual intercourse at least once per week during the study.

Judged by the Investigator to be in good general health other than ED.

Creatinine clearance (CrCl) >80 mL/min as calculated by Cockcroft-Gault.

Able and willing to comply with all study procedures, including use of eDiary/ePRO tools and adherence to dosing instructions.

Exclusion Criteria:

  • Use of nitrates or nitric oxide donors in any form.

Use of prohibited antihypertensive medications as defined in the protocol.

Use of phosphodiesterase type 5 (PDE5) inhibitors within 5 days prior to baseline.

Use of CYP450 inhibitors within 14 days prior to first dose.

Use of CYP450 inducers or St. John's Wort within 28 days prior to first dose.

Use of any prescription or non-prescription medications, herbal products, or dietary supplements not approved by the Investigator during the required restriction period.

Known hypersensitivity to sildenafil, tadalafil, vardenafil, peppermint oil, or any component of the investigational product.

Clinically significant abnormalities in screening laboratory tests, vital signs, or electrocardiograms, as judged by the Investigator.

Any hepatic impairment or abnormal liver function test results at screening.

Positive screening test for hepatitis B surface antigen, hepatitis C antibody, or HIV.

Clinically significant illness within 30 days prior to the first dose.

Significant cardiovascular disease, including recent myocardial infarction, unstable angina, uncontrolled hypertension, or severe arrhythmias.

History of stroke or neurological disorder that may affect sexual function.

Severe psychiatric disorder or substance abuse that may interfere with study participation.

Anatomical penile deformity (such as Peyronie's disease) that may interfere with erectile function assessments.

Positive urine drug screen for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencyclidine (PCP), or MDMA.

Alcohol consumption exceeding 15 units per week.

Initiation of new nicotine products during the study period.

Participation in another clinical trial (other than Hezkue/Hezkue Turbo studies) within 30 days prior to screening.

Blood donation or significant blood loss within 3 months prior to screening, or plasma donation within 14 days prior to screening.

Major surgery within 3 months or minor surgery within 1 month before screening.

Consumption of Seville oranges, grapefruit, or pomelo within 7 days before dosing.

Resting systolic blood pressure outside 90-140 mmHg, diastolic blood pressure outside 50-90 mmHg, or heart rate outside 50-100 beats per minute at screening.

Sexual partner is pregnant or unwilling to use effective contraception during the study.

Any condition that, in the Investigator's opinion, would make the participant unsuitable for the study.

Institutionalized individuals.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Hezkue
Participants receive Hezkue®, an oral liquid formulation of sildenafil, used on an on-demand basis for 12 weeks.
Drug: Hezkue
Hezkue® is an oral liquid formulation of sildenafil administered on an on-demand basis for the treatment period.
Other Names:
  • Sildenafil oral spray
Experimental: Hezkue Turbo
Participants receive Hezkue Turbo®, an oral liquid suspension delivering sildenafil via a metered-dose device, used on an on-demand basis for 12 weeks.
Drug: Hezkue Turbo
Hezkue Turbo® is an oral liquid suspension of sildenafil delivered via a metered-dose device, used on an on-demand basis.
Other Names:
  • Sildenafil liquid suspension
Active Comparator: Galotam
Participants receive Galotam®, a commercially available sildenafil product, used on an on-demand basis for 12 weeks.
Drug: Galotam
Galotam® is a commercially available sildenafil product administered on an on-demand basis.
Other Names:
  • Sildenafil tablet (Galotam)
Active Comparator: BlueChew
Participants receive BlueChew® sildenafil chewable tablets, used on an on-demand basis for 12 weeks.
Drug: BlueChew
BlueChew® sildenafil chewable tablets, used on an on-demand basis.
Other Names:
  • Sildenafil chewable tablet
Active Comparator: Pfizer Viagra
Participants receive Pfizer Viagra®, a standard oral tablet formulation of sildenafil, used on an on-demand basis for 12 weeks.
Drug: Pfizer Viagra
Pfizer Viagra® sildenafil tablets, administered on an on-demand basis.
Other Names:
  • Sildenafil citrate
Active Comparator: Aristo Sildaristo
Participants receive Aristo Sildaristo®, a commercially available sildenafil tablet product, used on an on-demand basis for 12 weeks.
Drug: Aristo Sildaristo
Aristo Sildaristo® is a commercially available sildenafil tablet product used on an on-demand basis.
Other Names:
  • Sildenafil
Active Comparator: Lemonaid Health Viagra
Participants receive Lemonaid Health-branded sildenafil (Viagra), used on an on-demand basis for 12 weeks.
Drug: Lemonaid Health Sildenafil
Lemonaid Health-branded sildenafil tablets (Viagra equivalent), administered on an on-demand basis.
Other Names:
  • Sildenafil (Lemonaid Health)
Active Comparator: Ro Sparks
Participants receive Ro Sparks®, a combination sildenafil + tadalafil product, used on an on-demand basis for 12 weeks.
Drug: Ro Sparks
Ro Sparks® is a combination sildenafil + tadalafil product administered on an on-demand basis.
Other Names:
  • Sildenafil + Tadalafil (Ro Sparks)
Active Comparator: Hims Hard Mints
Participants receive Hims Hard Mints®, a combination sildenafil + tadalafil formulation, used on an on-demand basis for 12 weeks.
Drug: Hims Hard Mints
Hims Hard Mints® is a combination formulation containing sildenafil + tadalafil, used on an on-demand basis.
Other Names:
  • Sildenafil + Tadalafil (Hims)
Active Comparator: Hello Cake ED Cake Meds
Participants receive Hello Cake ED Cake Meds®, a combination sildenafil + tadalafil formulation, used on an on-demand basis for 12 weeks.
Drug: Hello Cake ED Cake Meds
Hello Cake ED Cake Meds® is a combination sildenafil + tadalafil product administered on an on-demand basis.
Other Names:
  • Sildenafil + Tadalafil (Hello Cake)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in IIEF-EF Domain Score
Time Frame: Baseline to Week 12
Erectile function will be assessed using the International Index of Erectile Function-Erectile Function (IIEF-EF) domain score, which ranges from 1 to 30, with higher scores indicating better erectile function. Change from baseline to Week 12 will be compared across treatment arms.
Baseline to Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
SEP-Q2 Penetration Success Rate
Time Frame: Weeks 0-12
Proportion of "Yes" responses to Sexual Encounter Profile Question 2 (SEP-Q2: ability to achieve vaginal penetration) across all sexual attempts.
Weeks 0-12
SEP-Q3 Intercourse Success Rate
Time Frame: Weeks 0-12
Proportion of "Yes" responses to Sexual Encounter Profile Question 3 (SEP-Q3: ability to maintain erection through completion of intercourse) across all sexual attempts
Weeks 0-12
Erection Hardness Score (EHS)
Time Frame: Weeks 4, 8, and 12
Proportion of participants achieving an EHS ≥3 and ≥4 at Weeks 4, 8, and 12.
Weeks 4, 8, and 12
Global Assessment Question (GAQ)
Time Frame: Week 12
Proportion of participants responding "Yes" to the GAQ ("Has the treatment improved your erections?").
Week 12
Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) Total Score
Time Frame: Week 12
Participant-reported satisfaction with erectile dysfunction treatment measured using the EDITS questionnaire.
Week 12
Time-to-Onset of Effect
Time Frame: Weeks 0-12
Participant-reported time (in minutes) to erection sufficient for penetration after dosing, recorded via eDiary for each sexual attempt.
Weeks 0-12
Duration of Effect
Time Frame: Weeks 0-12
Participant-reported duration (in hours) of erectile effect after dosing, recorded via eDiary.
Weeks 0-12
Incidence of Adverse Events (AEs) and Serious AEs (SAEs)
Time Frame: Screening through Week 13
Frequency and severity of treatment-emergent adverse events, including cardiovascular, ophthalmologic, otologic, and other expected PDE5 inhibitor-related events.
Screening through Week 13
TSQM-II Scores (Effectiveness, Side Effects, Convenience, Global Satisfaction)
Time Frame: Week 12
Treatment satisfaction will be assessed using the Treatment Satisfaction Questionnaire for Medication, Version II (TSQM-II). Each TSQM-II domain (Effectiveness, Side Effects, Convenience, and Global Satisfaction) is scored from 0 to 100, with higher scores indicating greater satisfaction in that domain (and fewer perceived side effects on the Side Effects scale).
Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Aspargo Labs, Inc

Investigators

  • Study Director: Mario Guralnik, PhD, Aspargo Labs, Inc

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

January 1, 2026

Primary Completion (Estimated)

March 1, 2026

Study Completion (Estimated)

March 1, 2026

Study Registration Dates

First Submitted

November 14, 2025

First Submitted That Met QC Criteria

November 14, 2025

First Posted (Estimated)

November 17, 2025

Study Record Updates

Last Update Posted (Actual)

November 19, 2025

Last Update Submitted That Met QC Criteria

November 17, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ASP-011-SIL

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Erectile Dysfunction

Clinical Trials on Hezkue

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Sri Lanka

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe