Colpermin (Peppermint Oil)
Herbal antispasmodic for irritable bowel syndrome (IBS) symptom relief
Quick Facts About Colpermin
Key Takeaways About Colpermin
- Clinically proven for IBS: Multiple systematic reviews and meta-analyses confirm peppermint oil significantly reduces global IBS symptoms, abdominal pain and bloating compared to placebo
- Swallow capsules whole: Never chew, crush or break the enteric-coated capsules, and take at least 30 minutes before or after meals to prevent premature release and mouth/oesophageal irritation
- Contains peanut oil: Colpermin contains refined peanut (arachis) oil and must not be used by people with peanut or soya allergies
- Avoid with acid-reducing medicines: Do not take Colpermin at the same time as antacids, PPIs or H2 blockers, as these can dissolve the enteric coating prematurely
- Consult a doctor if symptoms persist: See your doctor if symptoms do not improve after 2 weeks, or immediately if you experience new bleeding, unexplained weight loss or worsening symptoms
What Is Colpermin and What Is It Used For?
Colpermin is a herbal medicine containing 187 mg of peppermint oil (Mentha x piperita L.) in enteric-coated capsules, used to relieve symptoms of irritable bowel syndrome (IBS) including mild gastrointestinal cramps, excessive gas and abdominal pain.
Colpermin belongs to a category of plant-based medicines used for functional gastrointestinal disorders. The active ingredient, peppermint oil, is a naturally derived essential oil extracted from the peppermint plant. Each capsule contains 187 mg (0.2 ml) of peppermint oil, which is standardised to ensure consistent therapeutic quality. The enteric coating is a key design feature of Colpermin: it protects the capsule from dissolving in the stomach, allowing it to travel intact to the intestines where the peppermint oil is released directly at the site of action.
The primary indication for Colpermin is irritable bowel syndrome (IBS), a chronic functional gastrointestinal disorder that affects an estimated 10-15% of the global population. IBS is characterised by recurrent abdominal pain associated with changes in bowel habits, including diarrhoea, constipation, or alternating patterns of both. The condition significantly impacts quality of life, work productivity and healthcare utilisation. Colpermin is indicated for the symptomatic relief of IBS, specifically targeting abdominal cramps, bloating, flatulence and abdominal pain.
Peppermint oil works primarily through calcium channel antagonism in gastrointestinal smooth muscle. By blocking the influx of calcium ions through voltage-gated calcium channels, peppermint oil reduces the contractility of smooth muscle cells in the intestinal wall. This relaxation of smooth muscle helps relieve the spasms and cramps that characterise IBS symptoms. Additionally, peppermint oil has demonstrated anti-inflammatory, antimicrobial and analgesic properties that may contribute to its therapeutic effects in IBS.
The clinical evidence supporting peppermint oil for IBS is substantial. A landmark meta-analysis published in the Journal of Clinical Gastroenterology (Khanna et al., 2014) analysed nine randomised controlled trials involving 726 patients and concluded that peppermint oil was significantly superior to placebo for global improvement of IBS symptoms (relative risk 2.39; 95% CI 1.93-2.97) and for improvement of abdominal pain (relative risk 1.78; 95% CI 1.43-2.20). The American College of Gastroenterology (ACG) conditionally recommends peppermint oil for the treatment of global IBS symptoms in their 2021 clinical guidelines, and the National Institute for Health and Care Excellence (NICE) also recognises antispasmodics, including peppermint oil, as a first-line pharmacological treatment for IBS.
You should only use Colpermin after a healthcare professional has confirmed your diagnosis of IBS. The symptoms of IBS can overlap with other, more serious gastrointestinal conditions, and it is essential to rule out conditions such as inflammatory bowel disease (IBD), coeliac disease and colorectal cancer before starting self-treatment.
What Should You Know Before Taking Colpermin?
Colpermin should not be used if you have liver disease, cholangitis, achlorhydria, gallstones, or allergies to peppermint oil, mentol, peanuts or soya. It is not recommended for children under 12 years or during pregnancy and breastfeeding.
Contraindications
There are several important contraindications for Colpermin that must be carefully considered before starting treatment. You must not take Colpermin if any of the following apply:
- Allergy to peppermint oil, menthol, or any other ingredients in the capsules (see full ingredients list in the composition section below)
- Peanut or soya allergy: Colpermin contains refined peanut (arachis) oil. If you are allergic to peanuts or soya, you must not use this medicine
- Liver disease: Peppermint oil is extensively metabolised by the liver, and impaired hepatic function may lead to accumulation and toxicity
- Cholangitis: Inflammation of the bile ducts may be worsened by the choleretic (bile-stimulating) properties of peppermint oil
- Achlorhydria: Absent or very low gastric acid production may cause premature dissolution of the enteric coating in the stomach, leading to local irritation
- Gallstones or gallbladder disease: Peppermint oil may stimulate bile flow, potentially causing biliary colic in patients with gallstones
Colpermin is not recommended for children under 12 years of age due to insufficient safety and efficacy data in this population. For adolescents aged 12-17, the standard adult dose of 1 capsule three times daily should be used without dose escalation.
Warnings and Precautions
While Colpermin is generally well tolerated, certain situations require caution. You should speak with your doctor if any of the following occur, even if you have a confirmed IBS diagnosis, as they may indicate a more serious underlying condition:
- Your symptoms become notably worse despite treatment
- You are over 40 years old and have not experienced IBS symptoms for a prolonged period, or your symptoms are different from previous episodes
- You have recently noticed blood in your stools
- You have experienced unexplained loss of appetite or weight loss
If you suffer from heartburn or hiatal hernia (a condition where part of the stomach slides up into the chest cavity), Colpermin may worsen these symptoms. The menthol in peppermint oil can relax the lower oesophageal sphincter, potentially allowing stomach acid to reflux into the oesophagus. If heartburn occurs or worsens during treatment, discontinue use and consult your healthcare provider.
Colpermin enteric-coated capsules must be swallowed whole and must not be broken, chewed, or taken with food. Breaking or chewing the capsules can cause premature release of peppermint oil, leading to irritation of the mouth, throat and oesophagus. This can also reduce the efficacy of the medicine, as the peppermint oil may be partially degraded by stomach acid before reaching the intestines.
Pregnancy and Breastfeeding
Due to insufficient safety data, Colpermin is not recommended during pregnancy, breastfeeding, or for women of childbearing potential who are not using contraception. While there is no direct evidence of teratogenicity, the precautionary principle applies. If you are pregnant, suspect you may be pregnant, or are planning to become pregnant, consult your healthcare provider before using this medicine. The same precaution applies to breastfeeding mothers, as it is unknown whether constituents of peppermint oil are excreted in human breast milk in clinically relevant amounts.
Driving and Operating Machinery
Colpermin has no known effect on the ability to drive or operate machinery. No impairment of alertness, concentration or reaction time has been reported in clinical studies. However, you are always responsible for assessing your own fitness to drive or perform tasks requiring heightened attention, considering all medicines you are taking and their potential combined effects.
How Does Colpermin Interact with Other Drugs?
Colpermin's main drug interactions involve acid-reducing medicines (antacids, PPIs, H2 blockers) which can prematurely dissolve the enteric coating. These medications should be taken at least 2 hours before or after Colpermin.
The enteric coating of Colpermin capsules is designed to remain intact in the acidic environment of the stomach and dissolve only in the more alkaline conditions of the small intestine. Any medicine that raises stomach pH (reduces acidity) can compromise this coating, causing the peppermint oil to be released prematurely in the stomach. This can lead to gastric irritation, heartburn and reduced therapeutic efficacy, as less peppermint oil reaches the intestines.
| Interacting Medicine | Examples | Effect | Recommendation |
|---|---|---|---|
| Proton pump inhibitors (PPIs) | Omeprazole, esomeprazole, lansoprazole, pantoprazole | Raises gastric pH, causing premature dissolution of enteric coating | Take Colpermin at least 2 hours before or after PPI |
| H2 receptor blockers | Ranitidine, famotidine, cimetidine | Reduces gastric acid, may cause premature release of peppermint oil | Take Colpermin at least 2 hours before or after H2 blocker |
| Antacids | Aluminium/magnesium hydroxide, calcium carbonate, sodium bicarbonate | Neutralises stomach acid, causing premature coating dissolution | Take Colpermin at least 2 hours before or after antacid |
Beyond the well-documented interaction with acid-reducing medicines, peppermint oil may also have pharmacokinetic interactions through inhibition of certain cytochrome P450 enzymes, particularly CYP3A4 and CYP1A2. While these effects are generally considered clinically insignificant at standard therapeutic doses of Colpermin, patients taking medicines with a narrow therapeutic index that are metabolised by these enzymes (such as ciclosporin, certain statins, or theophylline) should inform their healthcare provider before starting Colpermin.
Always inform your doctor or pharmacist about all medicines you are currently taking, have recently taken, or plan to take, including over-the-counter medicines, herbal products and dietary supplements.
Food and Drink Interactions
Food can trigger premature release of peppermint oil from the enteric-coated capsule. Therefore, Colpermin should be taken at least 30 minutes before or after a meal. Taking the capsule on an empty stomach with a glass of water ensures optimal transit to the small intestine where the coating is designed to dissolve. Hot drinks and acidic beverages should also be avoided immediately before or after taking Colpermin, as temperature and acidity changes may affect the integrity of the enteric coating.
What Is the Correct Dosage of Colpermin?
The standard adult dose is 1 capsule (187 mg peppermint oil) three times daily, which may be increased to a maximum of 2 capsules three times daily if needed. For adolescents aged 12-17, the dose is 1 capsule three times daily without dose escalation.
Always take Colpermin exactly as described in the patient information leaflet or as directed by your doctor, pharmacist or nurse. If you are unsure, consult a healthcare professional for guidance. The capsules must be swallowed whole with sufficient liquid and should never be chewed, crushed or split open.
Adults and Elderly
Standard Dosage for Adults (18+ years)
Recommended dose: 1 capsule three times daily
Maximum dose: 2 capsules three times daily (if needed)
Administration: Swallow whole with water, at least 30 minutes before or after meals
Duration: Usually 1-2 weeks per treatment course; maximum 3 months per course
The recommended starting dose for adults is 1 capsule (187 mg peppermint oil) taken three times daily. If symptoms are not adequately controlled at this dose, it may be increased to a maximum of 2 capsules three times daily. This dose escalation should ideally be discussed with a healthcare professional. The same dosage recommendations apply to elderly patients, as no specific dose adjustment is required based on age alone.
Adolescents (12-17 years)
Dosage for Adolescents (12-17 years)
Recommended dose: 1 capsule three times daily
Maximum dose: 1 capsule three times daily (do not increase)
Administration: Swallow whole with water, at least 30 minutes before or after meals
Children Under 12 Years
Colpermin is not recommended for children under 12 years of age. Insufficient safety and efficacy data are available for this age group. If a child requires treatment for gastrointestinal symptoms, parents should consult a paediatrician for appropriate alternatives.
Renal Impairment
There are currently no specific dosage recommendations for patients with impaired kidney function, as insufficient data are available. If you have known kidney disease, consult your doctor before using Colpermin.
| Patient Group | Dose | Frequency | Maximum Daily Dose |
|---|---|---|---|
| Adults (18+) | 1-2 capsules | 3 times daily | 6 capsules (1,122 mg) |
| Elderly | 1-2 capsules | 3 times daily | 6 capsules (1,122 mg) |
| Adolescents (12-17) | 1 capsule | 3 times daily | 3 capsules (561 mg) |
| Children (<12) | Not recommended | ||
Missed Dose
If you forget to take a dose, simply take your next dose at the usual time. Do not take a double dose to make up for the missed one. Missing an occasional dose is unlikely to significantly affect the overall therapeutic benefit, as the treatment effect builds gradually over the course of several days.
Overdose
If you or someone else takes too much Colpermin, contact a doctor, hospital emergency department or poison control centre immediately for risk assessment and advice. This is especially important if a child has accidentally ingested the medicine.
Symptoms of overdose may include:
- Severe gastrointestinal disturbance: Diarrhoea, rectal ulceration, nausea
- Neurological effects: Seizures, loss of consciousness, difficulty coordinating muscle movements (ataxia), and other central nervous system disturbances
- Respiratory effects: Breathing difficulties
- Cardiac effects: Heart rhythm disturbances (arrhythmias)
Peppermint oil overdose can be serious, particularly in young children. Keep Colpermin out of sight and reach of children at all times. If accidental ingestion occurs, seek medical attention promptly even if no symptoms are present.
What Are the Side Effects of Colpermin?
Common side effects include headache, heartburn, perianal discomfort, abnormal stool odour, dry mouth, stomach discomfort and nausea. Most side effects are mild and transient. Seek immediate medical help for signs of severe allergic reaction including anaphylaxis.
Like all medicines, Colpermin can cause side effects, although not everyone will experience them. Most reported side effects are mild to moderate in severity and are related to the pharmacological action of peppermint oil on the gastrointestinal tract. The enteric coating is specifically designed to minimise upper gastrointestinal side effects by releasing the peppermint oil in the intestines rather than the stomach.
Severe allergic reactions including anaphylactic shock (sudden severe allergic reaction with symptoms such as blood pressure drop and breathing difficulties), tremors or shaking, movement disorders with balance difficulties, slow heart rate, or widespread red skin rash. The frequency of these serious adverse effects is not known.
Common Side Effects
- Headache
- Heartburn (pyrosis)
- Perianal discomfort
- Abnormal stool odour
- Dry mouth
- Stomach discomfort
- Nausea
- Vomiting
Uncommon Side Effects
- Hypersensitivity reactions
- Itchy skin (pruritus)
- Gastrointestinal bleeding
- Blurred vision
Frequency Not Known
- Pain around the anal opening (perianal pain)
- Diarrhoea
- Difficulty or pain when urinating (dysuria)
- Inflammation of the glans penis (balanitis)
- Abnormal urine odour
Serious Side Effects (Seek Immediate Help)
- Anaphylactic shock (severe allergic reaction with breathing difficulty and blood pressure drop)
- Tremors or involuntary shaking
- Movement disorders with balance problems
- Slow heart rate (bradycardia)
- Widespread red skin rash
Heartburn is one of the most commonly reported side effects and occurs because peppermint oil can relax the lower oesophageal sphincter, allowing gastric acid to reflux into the oesophagus. This effect is more pronounced if capsules are chewed or broken, or if taken with food, as the enteric coating may dissolve prematurely. Taking the capsule correctly (whole, on an empty stomach) significantly reduces the risk of heartburn.
The perianal discomfort and unusual stool odour reported by some patients are related to the passage of unabsorbed menthol through the gastrointestinal tract. These effects are generally harmless and resolve spontaneously after discontinuation of treatment.
Reporting Side Effects
If you experience any side effects, including those not listed above, talk to your doctor or pharmacist. You can also report side effects directly to your national pharmacovigilance authority. In the UK, this is the Yellow Card Scheme (via MHRA). In the US, side effects can be reported to the FDA MedWatch programme. Reporting side effects helps authorities continuously monitor the benefit-risk balance of medicines.
How Should You Store Colpermin?
Store Colpermin below 25°C in the original packaging, protected from light and moisture. Keep out of sight and reach of children. Do not use after the expiry date printed on the pack.
Proper storage is essential to maintain the integrity and efficacy of Colpermin capsules. The enteric coating is sensitive to environmental conditions, and improper storage can compromise its functionality.
- Temperature: Store at or below 25°C (77°F). Do not refrigerate or freeze.
- Light and moisture: Keep in the original blister packaging to protect from light and moisture, as exposure to humidity can affect the enteric coating.
- Children: Keep out of sight and reach of children at all times.
- Expiry date: Do not use Colpermin after the expiry date stated on the outer carton and blister strip. The expiry date refers to the last day of that month.
- Disposal: Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer need. These measures help protect the environment.
Handle the blister packaging carefully when removing capsules, as the enteric coating can be fragile. Remove only one capsule at a time and take it immediately. Do not remove capsules from the blister in advance and store them loosely, as this exposes them to air and moisture.
What Does Colpermin Contain?
Each Colpermin enteric-coated capsule contains 187 mg of peppermint oil as the active ingredient, along with excipients including refined peanut (arachis) oil, white wax, gelatin and enteric coating polymers.
Active Ingredient
Each hard enteric-coated capsule contains 187 mg (0.2 ml) of peppermint oil (Mentha x piperita L., aetheroleum). Peppermint oil is a complex mixture of over 100 chemical compounds, with the principal active constituent being menthol (typically 30-55% of the oil by weight). Other important constituents include menthone (14-32%), menthyl acetate (2.8-10%), 1,8-cineole (eucalyptol, 3.5-14%) and limonene (1-5%).
Other Ingredients
Capsule contents:
- White wax
- Refined peanut (arachis) oil
- Gelatin
Capsule shell:
- Gelatin
- Indigotine (E132)
- Titanium dioxide (E171)
Enteric coating:
- Methacrylic acid-methyl methacrylate copolymer
- Methacrylic acid-ethyl acrylate copolymer
- Triethyl citrate
- Glycerol monostearate 40-55
- Macrogol
- Talc
Appearance and Packaging
Colpermin capsules are opaque with a light blue lower half and an opaque blue upper half separated by a dark blue band. Capsule dimensions are 19.4 mm x 6.8 mm. The capsules are supplied in blister strips of 10 capsules, with each pack containing 30 enteric-coated capsules (3 blister strips).
Colpermin is manufactured by Tillotts Pharma GmbH, Warmbacher Strasse 80, 79618 Rheinfelden, Germany.
Frequently Asked Questions About Colpermin
Colpermin is a herbal medicine containing peppermint oil, used to relieve symptoms of irritable bowel syndrome (IBS) including abdominal cramps, bloating, excessive gas (flatulence) and abdominal pain. The enteric-coated capsules ensure the peppermint oil is released in the intestines where it acts as a smooth muscle relaxant, reducing spasms and discomfort. It should only be used after a healthcare professional has confirmed your IBS diagnosis.
Take 1 capsule three times daily (or up to 2 capsules three times daily for adults if needed). Swallow capsules whole with a glass of water at least 30 minutes before or after meals. Never chew, crush or break the capsules, as this can cause irritation of the mouth and oesophagus and reduces the medicine's effectiveness. Handle the blister packaging carefully when removing capsules. Treatment usually lasts 1-2 weeks, and each course should not exceed 3 months.
You should not take Colpermin at the same time as antacids, proton pump inhibitors (PPIs like omeprazole or lansoprazole), or H2 receptor blockers (like ranitidine or famotidine). These acid-reducing medicines can dissolve the enteric coating prematurely, causing the peppermint oil to be released in the stomach instead of the intestines. This can lead to heartburn and stomach irritation. Allow at least 2 hours between taking Colpermin and any acid-reducing medicine.
No. Colpermin contains refined peanut (arachis) oil and must not be used by anyone with a peanut or soya allergy. Even though the oil is refined, there is still a potential risk of allergic reaction. If you have a peanut or soya allergy, speak with your doctor or pharmacist about alternative IBS treatments that do not contain peanut-derived ingredients.
Colpermin is not recommended during pregnancy or breastfeeding due to a lack of sufficient safety data. It is also not recommended for women of childbearing potential who are not using contraception. If you are pregnant, planning to become pregnant, or breastfeeding, consult your doctor before using this or any other medicine for your IBS symptoms. Your healthcare provider can discuss alternative options that have better-established safety profiles in pregnancy.
You should consult a doctor if your symptoms do not improve after 2 weeks of treatment, if symptoms worsen significantly, if you notice blood in your stools, or if you experience unexplained weight loss or loss of appetite. Also seek medical attention if you are over 40 and your symptoms have changed or returned after a long symptom-free period. Stop taking Colpermin and seek emergency help immediately if you experience signs of a severe allergic reaction (difficulty breathing, facial swelling, rapid drop in blood pressure).
References
- Khanna R, MacDonald JK, Levesque BG. Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and meta-analysis. J Clin Gastroenterol. 2014;48(6):505-512. doi:10.1097/MCG.0b013e3182a88357
- Alammar N, Wang L, Saberi B, et al. The impact of peppermint oil on the irritable bowel syndrome: a meta-analysis of the pooled clinical data. BMC Complement Med Ther. 2019;19(1):21. doi:10.1186/s12906-019-2530-7
- Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021;116(1):17-44. doi:10.14309/ajg.0000000000001036
- National Institute for Health and Care Excellence (NICE). Irritable bowel syndrome in adults: diagnosis and management. Clinical guideline [CG61]. Updated April 2017.
- British National Formulary (BNF). Peppermint oil monograph. Accessed February 2026.
- European Medicines Agency (EMA). Community herbal monograph on Mentha x piperita L., aetheroleum. EMA/HMPC/349466/2006.
- Ford AC, Talley NJ, Spiegel BMR, et al. Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis. BMJ. 2008;337:a2313. doi:10.1136/bmj.a2313
- Cash BD, Epstein MS, Shah SM. A novel delivery system of peppermint oil is an effective therapy for irritable bowel syndrome symptoms. Dig Dis Sci. 2016;61(2):560-571. doi:10.1007/s10620-015-3858-7
- Chumpitazi BP, Kearns GL, Shulman RJ. Review article: the physiological effects and safety of peppermint oil and its efficacy in irritable bowel syndrome and other functional disorders. Aliment Pharmacol Ther. 2018;47(6):738-752. doi:10.1111/apt.14519
- World Gastroenterology Organisation (WGO). Irritable Bowel Syndrome: a Global Perspective. WGO Global Guidelines. 2015.
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