Trial Outcomes & Findings for Antibacterial Mouthwash for Pharyngeal Gonorrhea Prevention (NCT NCT04966507)

NCT ID: NCT04966507

Last Updated: 2026-07-09

Results Overview

This outcome was assessed using self-reported questionnaire data asking participants to report "In the past 3 months, what proportion of days did you use the mouthwash?"

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

89 participants

Primary outcome timeframe

This outcome will be measured over each 12-week intervention period

Results posted on

2026-07-09

Participant Flow

Participants in this study were drawn from mSTUDY, an NIH/NIDA-funded longitudinal cohort study (U01 DA036267) designed to examine the impact of substance use and HIV among men. Participants in mSTUDY were recruited from two sites: a community-based organization providing sexual health services and a university-affiliated research clinic. Recruitment for this study began in February 2022 and concluded in August 2024.

Participant milestones

Participant milestones
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Period 1: First Intervention (12 weeks)
STARTED
45
44
Period 1: First Intervention (12 weeks)
COMPLETED
32
32
Period 1: First Intervention (12 weeks)
NOT COMPLETED
13
12
Period 2: Second Intervention (12 weeks)
STARTED
32
32
Period 2: Second Intervention (12 weeks)
COMPLETED
31
28
Period 2: Second Intervention (12 weeks)
NOT COMPLETED
1
4

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

This is a cross over with the same 89 participants completing both study arms

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=45 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=44 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Total
n=89 Participants
Total of all reporting groups
Age, Continuous
39 Years
n=20 Participants • This is a cross over with the same 89 participants completing both study arms
37 Years
n=20 Participants • This is a cross over with the same 89 participants completing both study arms
38 Years
n=40 Participants • This is a cross over with the same 89 participants completing both study arms
Sex: Female, Male
Female
0 Participants
n=20 Participants
0 Participants
n=20 Participants
0 Participants
n=40 Participants
Sex: Female, Male
Male
45 Participants
n=20 Participants
44 Participants
n=20 Participants
89 Participants
n=40 Participants
Race/Ethnicity, Customized
African American/Black, non-Hispanic
8 Participants
n=20 Participants
16 Participants
n=20 Participants
24 Participants
n=40 Participants
Race/Ethnicity, Customized
Hispanic
22 Participants
n=20 Participants
21 Participants
n=20 Participants
43 Participants
n=40 Participants
Race/Ethnicity, Customized
Other
2 Participants
n=20 Participants
2 Participants
n=20 Participants
4 Participants
n=40 Participants
Race/Ethnicity, Customized
White, non-Hispanic
11 Participants
n=20 Participants
4 Participants
n=20 Participants
15 Participants
n=40 Participants
Race/Ethnicity, Customized
Unknown
2 Participants
n=20 Participants
1 Participants
n=20 Participants
3 Participants
n=40 Participants

PRIMARY outcome

Timeframe: This outcome will be measured over each 12-week intervention period

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome was assessed using self-reported questionnaire data asking participants to report "In the past 3 months, what proportion of days did you use the mouthwash?"

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 1 (first 12-weeks) · 75%-100% of days
22 Participants
22 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 1 (first 12-weeks) · 50%-74% of days
5 Participants
5 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 1 (first 12-weeks) · 25%-49% of days
3 Participants
3 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 1 (first 12-weeks) · 0%-24% of days
2 Participants
2 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 2 (second 12-weeks after crossover) · 75%-100% of days
16 Participants
16 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 2 (second 12-weeks after crossover) · 50%-74% of days
10 Participants
8 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 2 (second 12-weeks after crossover) · 25%-49% of days
2 Participants
3 Participants
Mouthwash Adherence - Percent of Days Mouthwash Used
Period 2 (second 12-weeks after crossover) · 0%-24% of days
3 Participants
1 Participants

PRIMARY outcome

Timeframe: This outcome will be measured at 12-weeks post intervention.

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome will be assessed using self-reported questionnaire and is intended to measure acceptability of mouthwash as prevention strategy for pharyngeal gonnorrhea. Participants were asked "Did you experience any of the following difficulties using the mouthwash?" with answer choices including: It was hard to gargle/rinse I didn't like the mouthwash flavor/taste It was uncomfortable Amount of liquid was too much Amount of gargling time was too long

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 1 (first 12-weeks) · It was hard to gargle/rinse
1 Participants
2 Participants
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 1 (first 12-weeks) · It was not hard to gargle/rinse
31 Participants
30 Participants
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 2 (second 12-weeks after crossover) · It was hard to gargle/rinse
3 Participants
1 Participants
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 2 (second 12-weeks after crossover) · It was not hard to gargle/rinse
28 Participants
27 Participants
Mouthwash Acceptability - Number of Participants Who Reported it Was Hard to Gargle/Rinse With Mouthwash
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants

PRIMARY outcome

Timeframe: This outcome will be measured at 12-weeks post intervention.

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome will be assessed using self-reported questionnaire and is intended to measure acceptability of mouthwash as prevention strategy for pharyngeal gonnorrhea. Participants were asked "Did you experience any of the following difficulties using the mouthwash?" with answer choices including: It was hard to gargle/rinse I didn't like the mouthwash flavor/taste It was uncomfortable Amount of liquid was too much Amount of gargling time was too long

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 1 (first 12-weeks) · Disliked mouthwash taste/flavor
4 Participants
4 Participants
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 1 (first 12-weeks) · Did not dislike mouthwash taste/flavor
28 Participants
28 Participants
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 2 (second 12-weeks after crossover) · Disliked mouthwash taste/flavor
1 Participants
4 Participants
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 2 (second 12-weeks after crossover) · Did not dislike mouthwash taste/flavor
30 Participants
24 Participants
Mouthwash Acceptability - Number of Participants Who Did Not Like Mouthwash Flavor/Taste
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants

PRIMARY outcome

Timeframe: This outcome will be measured at 12-weeks post intervention.

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome will be assessed using self-reported questionnaire and is intended to measure acceptability of mouthwash as prevention strategy for pharyngeal gonnorrhea. Participants were asked "Did you experience any of the following difficulties using the mouthwash?" with answer choices including: It was hard to gargle/rinse I didn't like the mouthwash flavor/taste It was uncomfortable Amount of liquid was too much Amount of gargling time was too long

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 1 (first 12-weeks) · Mouthwash use was uncomfortable
4 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 1 (first 12-weeks) · Mouthwash use was not uncomfortable
28 Participants
32 Participants
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 2 (second 12-weeks after crossover) · Mouthwash use was uncomfortable
2 Participants
1 Participants
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 2 (second 12-weeks after crossover) · Mouthwash use was not uncomfortable
29 Participants
27 Participants
Mouthwash Acceptability - Number of Participants Who Said Mouthwash Use Was Uncomfortable
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants

PRIMARY outcome

Timeframe: This outcome will be measured at 12-weeks post intervention.

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome will be assessed using self-reported questionnaire and is intended to measure acceptability of mouthwash as prevention strategy for pharyngeal gonnorrhea. Participants were asked "Did you experience any of the following difficulties using the mouthwash?" with answer choices including: It was hard to gargle/rinse I didn't like the mouthwash flavor/taste It was uncomfortable Amount of liquid was too much Amount of gargling time was too long

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 1 (first 12-weeks) · Amount of liquid was too much
2 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 1 (first 12-weeks) · Amount of liquid was not too much
30 Participants
32 Participants
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 2 (second 12-weeks after crossover) · Amount of liquid was too much
1 Participants
1 Participants
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 2 (second 12-weeks after crossover) · Amount of liquid was not too much
30 Participants
27 Participants
Mouthwash Acceptability - Number of Participants Who Said Amount of Liquid Was Too Much
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants

PRIMARY outcome

Timeframe: This outcome will be measured at 12-weeks post intervention.

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

This outcome will be assessed using self-reported questionnaire and is intended to measure acceptability of mouthwash as prevention strategy for pharyngeal gonnorrhea. Participants were asked "Did you experience any of the following difficulties using the mouthwash?" with answer choices including: It was hard to gargle/rinse I didn't like the mouthwash flavor/taste It was uncomfortable Amount of liquid was too much Amount of gargling time was too long

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 2 (second 12-weeks after crossover) · Gargling time was not too long
30 Participants
27 Participants
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 1 (first 12-weeks) · Gargling time was too long
2 Participants
3 Participants
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 1 (first 12-weeks) · Gargling time was not too long
30 Participants
29 Participants
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 1 (first 12-weeks) · Lost to follow-up
0 Participants
0 Participants
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 2 (second 12-weeks after crossover) · Gargling time was too long
1 Participants
1 Participants
Mouthwash Acceptability - Number of Participants Who Said Gargling Time Was Too Long
Period 2 (second 12-weeks after crossover) · Lost to follow-up
1 Participants
4 Participants

SECONDARY outcome

Timeframe: Past 12 weeks

Population: Among the 45 participants assigned to the active-to-placebo sequence and the 44 participants assigned to the placebo-to-active sequence, 32 participants in each sequence completed the first 12-week follow-up assessment. Among the 32 participants in active-to-placebo sequence that completed the 12-week assessment, 31 completed the 24-week assess. Among the 32 participants in placebo-to-active sequence that completed the 12-week assessment, 28 completed the 24-week assess.

Laboratory confirmed pharyngeal gonorrhea

Outcome measures

Outcome measures
Measure
Listerine Cool Mint Antiseptic Mouthwash, Then Biotene Oral Rinse
n=32 Participants
Daily use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash) for 12-weeks, followed by daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks.
Biotene Oral Rinse, Then Listerine Cool Mint Antiseptic Mouthwash
n=32 Participants
Daily use of a placebo mouthwash (Biotene Oral Rinse) for 12-weeks, followed by 12-weeks of dialy use of an antibacterial mouthwash (Listerine Cool Mint Antiseptic Mouthwash)
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 1 (first 12-weeks) · Positive
2 Participants
0 Participants
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 1 (first 12-weeks) · Negative
30 Participants
32 Participants
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 1 (first 12-weeks) · Not Done
0 Participants
0 Participants
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 2 (second 12-weeks after crossover) · Positive
0 Participants
1 Participants
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 2 (second 12-weeks after crossover) · Negative
31 Participants
27 Participants
Pharyngeal Gonorrhea - Laboratory Testing Results
Pharyngeal gonorrhea laboratory results, period 2 (second 12-weeks after crossover) · Not Done
1 Participants
4 Participants

Adverse Events

1. Listerine Cool Mint Antiseptic Mouthwash

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Biotene Oral Rinse

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Marjan Javanbakht

University of California Los Angeles

Phone: 310-825-3234

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place