Irritable Bowel Syndrome (IBS)NCT06914921
Enteric-Coated Peppermint Oil Versus Standard Antispasmodic in SLC6A4 (5-HTTLPR) Carriers With Irritable Bowel Syndrome.
A study testing Peppermint Oil and A standard antispasmodic in people with Irritable Bowel Syndrome (IBS), run by S.LAB (SOLOWAYS) at 1 site in Russia.
Trial summary
This study is a non-inferiority, double-blind, randomized controlled trial comparing enteric-coated peppermint oil with a standard antispasmodic (e.g., mebeverine) in adult IBS patients who carry at least one "S" allele in the SLC6A4 (5-HTTLPR) polymorphism. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Irritable Bowel Syndrome (IBS)
- What is being tested?
- Peppermint Oil and A standard antispasmodic
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 224 participants
- Where
- 1 siteRussia
- Study dates
- 4 Feb 2024to 1 Feb 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18-65 years.
- Diagnosis of Irritable Bowel Syndrome by Rome IV criteria, with at least moderate severity (IBS-SSS ≥ 175).
- SLC6A4 genotyping confirms at least one S allele (SS or SL).
- Able and willing to provide informed consent and comply with study procedures.
Who cannot join
- L/L genotype of 5-HTTLPR.
- Known organic GI diseases (e.g., IBD, celiac disease).
- Severe/unstable comorbidities (e.g., cardiac, hepatic, or renal dysfunction).
- Use of peppermint oil, antispasmodics, or investigational drugs within 30 days prior to enrollment.
- . Known hypersensitivity to peppermint or mebeverine.
- Pregnancy or breastfeeding.
- Significant psychiatric illness that, in the investigator's judgment, might interfere with participation.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: "A Non-Inferiority Randomized Controlled Trial of Enteric-Coated Peppermint Oil Versus Standard Antispasmodic in SLC6A4 (5-HTTLPR) Carriers With Irritable Bowel Syndrome."
This study is a non-inferiority, double-blind, randomized controlled trial comparing enteric-coated peppermint oil with a standard antispasmodic (e.g., mebeverine) in adult IBS patients who carry at least one "S" allele in the SLC6A4 (5-HTTLPR) polymorphism. The primary goal is to see whether peppermint oil provides symptom relief (measured by IBS severity scores) that is not worse than the antispasmodic by more than a predefined margin (30 points on the IBS-SSS). Secondary goals include evaluating differences in abdominal pain, stool patterns, quality of life, and adverse event profiles, with a focus on peppermint oil's tolerability. About 224 participants (112 per arm) will be enrolled, with allowances for dropout, to detect non-inferiority at 80% power. After 12 weeks of treatment, results will inform whether peppermint oil is a viable, well-tolerated alternative to standard antispasmodics, especially in patients with heightened GI sensitivity linked to the SLC6A4 polymorphism.
Read the detailed description
This double-blind, parallel-group, non-inferiority RCT will randomize ~250 adults (18-65 y) who meet Rome IV criteria for IBS and carry at least one short 5-HTTLPR (SLC6A4) allele to enteric-coated peppermint-oil capsules (180 mg three times daily) or the standard antispasmodic mebeverine (135 mg three times daily) for 12 weeks. Because the S-allele reduces serotonin-transporter expression and heightens visceral sensitivity, the study targets a genetically defined subgroup in which menthol's smooth-muscle-relaxing calcium-channel blockade may yield clinically meaningful benefit with fewer anticholinergic effects. Randomisation (1 : 1) is web-based, stratified by genotype and centre, and treatments are packaged identically to maintain blinding of participants, investigators, and outcome assessors. The primary endpoint is change from baseline in the IBS Severity Scoring System at week 12; non-inferiority is met if the upper bound of the two-sided 95 % CI for the treatment difference (peppermint - mebeverine) is ≤ +30 points. A mixed-model repeated-measures analysis will be applied to both intention-to-treat and per-protocol populations, providing 80 % power with ~112 evaluable patients per arm. Secondary outcomes include abdominal-pain intensity, stool form, quality of life, global satisfaction, and adverse events; safety is tracked via weekly contacts, laboratory tests, and an independent data-safety monitoring board. Demonstrating that peppermint oil is at least as effective as mebeverine while better tolerated would support its use as a genotype-guided first-line therapy for IBS.
- Conditions
- Irritable Bowel Syndrome (IBS)
- Being tested
- Peppermint Oil, A standard antispasmodic
- Keywords
- supplements, genetics, peppermint oil
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Peppermint OilDietary supplement
Enteric-coated peppermint oil capsules (~180 mg total peppermint oil/ capsule) to ensure release in the small intestine.
1 capsule three times daily, 30 minutes before meals, for 12 weeks.
A standard antispasmodicDrug
A standard antispasmodic (e.g., mebeverine 135 mg). 1 tablet three times daily, before meals, for 12 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Enteric-coated peppermint oil capsules (~180 mg total peppermint oil/ capsule) to ensure release in | Experimental | Not described Receives: Dietary Supplement: Peppermint Oil |
| A standard antispasmodiс | Active comparator | A standard antispasmodic (e.g., mebeverine 135 mg). Receives: Drug: A standard antispasmodic |
What is being measured
The primary outcome is the main question the study is designed to answer.
Irritable Bowel Syndrome
Symptom severity in this trial is captured with the IBS-SSS (IBS Severity Scoring System): 0 = no symptoms to 500 = most severe symptoms
Measured: 12 weeks
Secondary outcomes (7)
Numeric Rating Scale (for abdominal pain)
Range: 0 = no pain to 10 = worst imaginable pain
Measured: 12 weeks
Abdominal Pain: Measured by visual analog score
0 as a minimum value and 10 maximum value
Measured: 12 weeks
Stool Consistency: Bristol Stool Form Scale
range 1-7, 1 = separate hard lumps/constipation, 7 = watery stool/diarrhea; higher scores indicate looser stool
Measured: 12 weeks
Quality of Life: Irritable Bowel Syndrome Quality of Life Questionnaire
transformed score 0-100; higher scores indicate better IBS-specific quality of life
Measured: 12 weeks
Quality of Life: 36-Item Short Form Health Survey
domain and summary scores 0-100; higher scores indicate better health-related quality of life
Measured: 12 weeks
Adverse Events: Incidence
Number of any adverse events
Measured: 12 weeks
Global Patient Satisfaction: Five-point Likert Scale
ange 1-5 (1 = very dissatisfied, 5 = very satisfied); higher scores indicate greater satisfaction
Measured: 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Apr 2025
- Study start4 Feb 2024
- Primary completion17 Jan 2025
- Study completion1 Feb 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel Syndrome (IBS)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 224 participants (actual)
Sponsor and investigators
- Lead sponsor
- S.LAB (SOLOWAYS)
- Sponsor type
- University, hospital or other
- Collaborators
- Center for New Medical Technologies, Novosibirsk, Russia
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06914921
- Sponsor's protocol ID
- SW027
- Status last verified
- Apr 2025
- First submitted
- 4 Apr 2025
- Last updated
- 23 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- "A Non-Inferiority Randomized Controlled Trial of Enteric-Coated Peppermint Oil Versus Standard Antispasmodic in SLC6A4 (5-HTTLPR) Carriers With Irritable Bowel Syndrome."
- ClinicalTrials.gov ID
- NCT06914921
- Acronym / sponsor ID
- SW027
- Conditions
- Irritable Bowel Syndrome (IBS)
- Keywords
- supplements, genetics, peppermint oil
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 224 participants (actual)
- Lead sponsor
- S.LAB (SOLOWAYS)University, hospital or other
- Collaborators
- Center for New Medical Technologies, Novosibirsk, Russia
- Study start
- 4 Feb 2024 (actual)
- Primary completion
- 17 Jan 2025 (actual)
- Study completion
- 1 Feb 2025 (actual)
- First posted
- 7 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a non-inferiority, double-blind, randomized controlled trial comparing enteric-coated peppermint oil with a standard antispasmodic (e.g., mebeverine) in adult IBS patients who carry at least one "S" allele in the SLC6A4 (5-HTTLPR) polymorphism. The primary goal is to see whether peppermint oil provides symptom relief (measured by IBS severity scores) that is not worse than the antispasmodic by more than a predefined margin (30 points on the IBS-SSS). Secondary goals include evaluating differences in abdominal pain, stool patterns, quality of life, and adverse event profiles, with a focus on peppermint oil's tolerability. About 224 participants (112 per arm) will be enrolled, with allowances for dropout, to detect non-inferiority at 80% power. After 12 weeks of treatment, results will inform whether peppermint oil is a viable, well-tolerated alternative to standard antispasmodics, especially in patients with heightened GI sensitivity linked to the SLC6A4 polymorphism.
Detailed description
This double-blind, parallel-group, non-inferiority RCT will randomize ~250 adults (18-65 y) who meet Rome IV criteria for IBS and carry at least one short 5-HTTLPR (SLC6A4) allele to enteric-coated peppermint-oil capsules (180 mg three times daily) or the standard antispasmodic mebeverine (135 mg three times daily) for 12 weeks. Because the S-allele reduces serotonin-transporter expression and heightens visceral sensitivity, the study targets a genetically defined subgroup in which menthol's smooth-muscle-relaxing calcium-channel blockade may yield clinically meaningful benefit with fewer anticholinergic effects. Randomisation (1 : 1) is web-based, stratified by genotype and centre, and treatments are packaged identically to maintain blinding of participants, investigators, and outcome assessors. The primary endpoint is change from baseline in the IBS Severity Scoring System at week 12; non-inferiority is met if the upper bound of the two-sided 95 % CI for the treatment difference (peppermint - mebeverine) is ≤ +30 points. A mixed-model repeated-measures analysis will be applied to both intention-to-treat and per-protocol populations, providing 80 % power with ~112 evaluable patients per arm. Secondary outcomes include abdominal-pain intensity, stool form, quality of life, global satisfaction, and adverse events; safety is tracked via weekly contacts, laboratory tests, and an independent data-safety monitoring board. Demonstrating that peppermint oil is at least as effective as mebeverine while better tolerated would support its use as a genotype-guided first-line therapy for IBS.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Enteric-coated peppermint oil capsules (~180 mg total peppermint oil/ capsule) to ensure release in | Experimental | Dietary Supplement: Peppermint Oil |
| A standard antispasmodiс | Active comparator | Drug: A standard antispasmodicA standard antispasmodic (e.g., mebeverine 135 mg). |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults aged 18-65 years.
- Diagnosis of Irritable Bowel Syndrome by Rome IV criteria, with at least moderate severity (IBS-SSS ≥ 175).
- SLC6A4 genotyping confirms at least one S allele (SS or SL).
- Able and willing to provide informed consent and comply with study procedures.
Key exclusion criteria (7 listed)
- L/L genotype of 5-HTTLPR.
- Known organic GI diseases (e.g., IBD, celiac disease).
- Severe/unstable comorbidities (e.g., cardiac, hepatic, or renal dysfunction).
- Use of peppermint oil, antispasmodics, or investigational drugs within 30 days prior to enrollment.
- . Known hypersensitivity to peppermint or mebeverine.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Peppermint OilEnteric-coated peppermint oil capsules (~180 mg total peppermint oil/ capsule) to ensure release in the small intestine. 1 capsule three times daily, 30 minutes before meals, for 12 weeks. | Dietary supplement | Enteric-coated peppermint oil capsules (~180 mg total peppermint oil/ capsule) to ensure release in |
| A standard antispasmodicA standard antispasmodic (e.g., mebeverine 135 mg). 1 tablet three times daily, before meals, for 12 weeks. | Drug | A standard antispasmodiс |
Primary outcome
Irritable Bowel Syndrome
Time frame: 12 weeks
Symptom severity in this trial is captured with the IBS-SSS (IBS Severity Scoring System): 0 = no symptoms to 500 = most severe symptoms
7 secondary outcomes
Numeric Rating Scale (for abdominal pain)
Time frame: 12 weeks
Abdominal Pain: Measured by visual analog score
Time frame: 12 weeks
Stool Consistency: Bristol Stool Form Scale
Time frame: 12 weeks
Quality of Life: Irritable Bowel Syndrome Quality of Life Questionnaire
Time frame: 12 weeks
Quality of Life: 36-Item Short Form Health Survey
Time frame: 12 weeks
Adverse Events: Incidence
Time frame: 12 weeks
Global Patient Satisfaction: Five-point Likert Scale
Time frame: 12 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Apr 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Peppermint Oil and A standard antispasmodic in people with Irritable Bowel Syndrome (IBS), run by S.LAB (SOLOWAYS) at 1 site in Russia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Russia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Irritable Bowel Syndrome (time frame: 12 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Apr 2025.