Molaxole (Macrogol)

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Molaxole (Macrogol)

Method of action: Laxative

Treatment option:

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Molaxole (Macrogol)

This section defines the identity and classification of the drug entity Molaxole, focusing on its composition, form, and general therapeutic purpose, strictly using authoritative, verifiable facts.

Property Description
Active ingredient Macrogol 3350 (Polyethylene Glycol)
Form Powder for Oral Solution (Sachets)
Pharmacological class Osmotic Laxative
Common use Relief from difficult or infrequent bowel movements
Origin Synthetic Polymer

What Type of Medicine is Molaxole (Macrogol)?

Molaxole is a pharmaceutical preparation classified as an Osmotic Laxative, whose primary active ingredient is Macrogol 3350, also known as Polyethylene Glycol (PEG). This medicine is fundamentally designed to assist in the gentle movement of the bowels. Macrogol 3350 is cataloged as a laxative by the World Health Organization's Anatomical Therapeutic Chemical (ATC) classification system. As an Osmotic Laxative, its general purpose is to relieve difficulty associated with passing hard or dry material. This classification ensures that the medicine works via water retention rather than through direct chemical stimulation, making it distinct from other classes of bowel aids. The drug entity is typically manufactured and marketed as a Powder for Oral Solution in pre-measured sachets, a presentation favored for patient convenience and accurate reconstitution. Macrogol-based treatments are clinically recognized for providing effectiveness compared to other common osmotic agents.


The Composition of Molaxole: Synthetic Polymer and Electrolytes

The active ingredient, Macrogol 3350, is a synthetic polymer that is minimally absorbed by the body, allowing it to remain inert and effective within the gastrointestinal tract. Macrogol is the component responsible for the core physiological action of the drug. A distinguishing feature of Molaxole is its formulation as a combination product that includes essential electrolytes—specifically Sodium Chloride, Sodium Bicarbonate, and Potassium Chloride. These added salts serve to maintain the body's normal salt and water balance by ensuring that the osmotic process used for stool softening does not inadvertently lead to significant fluid or electrolyte depletion within the body.


How Molaxole Differs from Other Laxatives

Molaxole’s mechanism differs from Stimulant Laxatives, which chemically irritate the colon lining to trigger muscle contractions; instead, Macrogol relies on a physical action. The unique benefit of this osmotically acting substance is its ability to bind water and increase the stool volume, thereby promoting softening and facilitating the normalisation of motility in the colon. This non-stimulant approach is often favored for patients, including those with chronic needs, because it provides a more regulated and less aggressive means to encourage evacuation compared to agents that rely on forced muscular or nerve stimulation. The fixed-dose combination with electrolytes is a standard formulation in this class, shared with other popular brands like Movicol and Laxido.

Regulatory References

  1. Polyethylene Glycol - StatPearls - NIH

What side effects are possible with Molaxole (Macrogol)?

Possible Side Effects and Safety Information

Official regulatory documents classify adverse reactions to Macrogol 3350 with electrolytes primarily within the Gastrointestinal Disorders system, reflecting the medicine’s osmotic action. The majority of reactions are related to the digestive tract and are generally mild and dose-dependent.

Reactions classified as Very Common include abdominal discomfort, pain, distension, flatulence, nausea, and diarrhoea. Common reactions documented in official labeling include vomiting and anal discomfort. These common effects are often associated with the initial phase of treatment or high-dose regimens, such as when treating faecal impaction.

The most significant safety consideration is the Very Rare potential for severe Immune System Disorders. These serious adverse reactions include systemic hypersensitivity reactions such as anaphylaxis and angioedema. Less common effects are categorized under Metabolism and Nutrition Disorders, such as the potential for electrolyte disturbances (e.g., hypokalaemia), which is a noted risk associated with prolonged, high-dose exposure.

Safety notes specify that the medicine is strictly contraindicated in the presence of acute bowel pathologies, including confirmed or suspected intestinal obstruction, bowel perforation, toxic megacolon, or severe inflammatory bowel disease (e.g., Crohn's disease or ulcerative colitis). Furthermore, regulatory information includes specific safety considerations for at-risk populations, such as the required monitoring of electrolyte levels in pediatric patients and those with pre-existing cardiac or renal impairment.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Molaxole (Macrogol 3350/Electrolyte combinations) describes overdose as primarily a risk of severe fluid and electrolyte imbalance due to the drug’s osmotic action.

Documented Manifestations

Overdose typically presents with severe gastrointestinal symptoms including profound abdominal pain and distension, along with extensive fluid loss through severe diarrhoea and vomiting. Signs of systemic instability, such as increasing fatigue, confusion, new oedema, or shortness of breath, may indicate a critical fluid or electrolyte shift.

Severe Outcomes and Required Actions

Regulators explicitly note the potential for severe, life-threatening outcomes, including seizure and cardiac failure, resulting from uncorrected electrolyte abnormalities. The risk of oesophageal rupture is also noted, particularly following excessive vomiting. Elderly patients are documented as being at a higher risk for serious complications.

In the event of an overdose or suspicion of severe electrolyte shifts, regulatory guidance mandates that treatment be stopped immediately. Management is strictly symptomatic and supportive, focused on the correction of these imbalances, as no specific antidote is known. Immediate medical assistance or emergency services must be contacted if the affected individual has collapsed, had a seizure, or is experiencing trouble breathing.

Therapeutic Uses of Molaxole (Macrogol)

Quick Facts: Therapeutic Applications

  • Targeted Use: Provides support for managing constipation.
  • Specific Application: Assists in resolving faecal impaction, a build-up of hardened stool.
  • Pre-Procedure Use: Used as a preparation to assist in cleansing the bowel before certain medical procedures.

Molaxole (Macrogol), an agent that works in the digestive tract, is primarily used to address a patient's difficulty with passing stool. The compound acts to soften the stool and promote passage, assisting in the relief of associated discomfort. It is an approved treatment to help restore regular bowel function in adults and children.

The medication is also indicated for the management of faecal impaction, which is defined as chronic, severe constipation that results in a significant collection of hard faeces in the rectum or colon. In this context, it is used to assist in the controlled evacuation of the mass.

Furthermore, the compound is employed to facilitate bowel cleansing as a necessary step prior to specific diagnostic tests or surgical procedures on the colon. This ensures the intestinal tract is clear for the successful completion of the procedure.

Eligibility and Restrictions for Use

Who can and cannot use Molaxole (Macrogol)?

Official regulatory information strictly defines the populations allowed to use this medicine and those for whom its use is prohibited (contraindicated).

Eligibility Status

Population Group Eligibility Ruling (Official Regulatory Status)
Eligible Population Adults and adolescents 12 years of age.
Pediatric Use Not recommended for children below 12 years of age, as safety and effectiveness have not been established for this specific product/dosage.
Pregnancy and Lactation Can be used during pregnancy and breastfeeding, as systemic exposure to Macrogol 3350 is negligible.
Renal Impairment No dosage change is necessary.

Absolute Contraindications (Must Not Use)

Molaxole is formally contraindicated in patients with certain pre-existing conditions that involve the structural or functional integrity of the bowel. Patients must not take this medicine if they have:

  • A known hypersensitivity or allergy to the active substance (Macrogol/Polyethylene Glycol) or any of the excipients.
  • Intestinal perforation or a perforated gut wall.
  • Intestinal obstruction (bowel blockage), ileus (paralysis of the bowel), or suspicion of symptomatic stenosis.
  • Severe inflammatory conditions of the intestinal tract, including ulcerative colitis, Crohn's disease, or toxic megacolon.

Use Considerations

For patients with impaired cardiovascular function who are treating faecal impaction, official documentation mandates that the dose must be divided so that no more than two sachets are taken in any one hour.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Molaxole (Macrogol 3350) is defined by two primary interaction types that occur within the digestive tract, consistent with the drug's minimal systemic absorption.


Alteration of Oral Drug Absorption

The most prominent pharmacokinetic-related interaction involves the transient reduction in the absorption of other co-administered oral medicines. This effect is documented to occur because Macrogol 3350 increases the gastrointestinal transit rate, reducing the time available for absorption of other substances. Regulatory documents note isolated reports of decreased efficacy with certain medicines, such as anti-epileptics (e.g., Levetiracetam, Phenytoin). To mitigate this potential for reduced exposure, a mandatory timing rule applies: other oral medicines should not be taken for one hour before and one hour after the administration of the Macrogol solution.


Physical Interaction with Food Thickeners

A separate and critical interaction is a physical incompatibility with specific products. Macrogol 3350 is documented to counteract the thickening effect of starch-based food thickeners, resulting in the liquid mixture becoming thin and watery. This physical compromise is highly relevant for patients with dysphagia (swallowing difficulties), as the loss of viscosity creates a significantly increased risk of aspiration. Due to this safety concern, official documentation restricts the direct mixing of Macrogol powder with starch-thickened liquids.

Mechanism of Action

The mechanism of Macrogol 3350 is primarily a physical osmotic action, targeting water molecules within the gut lumen. The polymer is minimally absorbed and strongly binds water via hydrogen bonding, which establishes a steep osmotic gradient across the colonic mucosa. This action prevents the normal reabsorption of water, causing a sustained increase in the fluid volume and hydration of the intestinal contents.

The significant increase in the volume and fluidity of the contents acts as a natural, mechanical stimulus. This physical distension triggers the intrinsic neuromuscular pathways of the enteric nervous system in the colon wall. This action triggers a regulated propulsive peristalsis, which facilitates the transportation of the hydrated contents and results in a change in colonic transit time.

The accompanying electrolytes (e.g., Sodium, Potassium) establish an isotonic environment that modulates the effect of the osmotic action on systemic fluid and electrolyte balance. The isotonic fluid composition influences the shift of the body's own salts, modulating the effect of the osmotic action on fluid dynamics across the intestinal barrier.

Dosage and Administration Information

How to Use Molaxole (Macrogol) for Constipation and Impaction

Molaxole is administered exclusively via the oral route as a powder that must be reconstituted with water immediately before consumption. It may be taken at any time of day, with or without food. The medicine is primarily used under two distinct dosing schedules for adults and adolescents aged 12 years and over, as specified in regulatory prescribing information.


Dosing Schedules and Duration

Indication Starting Dose Dosing Pattern Typical Duration Limit
Chronic Constipation 1 sachet daily Adjusted between 1 and 3 sachets daily, taken in divided doses. Up to 2 weeks for initial treatment.
Faecal Impaction 8 sachets daily Consumed in full over a 6-hour period. Does not exceed 3 days

Preparation and Administration Protocol

For a single-sachet dose, the powder must be dissolved in approximately 125 mL of water. The maximum recommended dose for chronic constipation is 3 sachets daily. For the higher-dose faecal impaction regimen, patients may dissolve the total 8 sachets in 1 litre of water. The reconstituted solution must be consumed within 24 hours if stored in a refrigerator. A specific administration instruction requires that other oral medicines should not be taken within one hour before, during, or one hour after taking Molaxole to avoid potential effects on absorption.

Recent Clinical Evidence

Research evidence / Overview of Studies for Molaxole (Macrogol)

Evidence for Use in Managing Chronic Constipation

Research exploring the evidence base for functional chronic constipation has primarily relied on Randomized Controlled Trials (RCTs) and comprehensive Systematic Reviews. These studies examined the Macrogol formulation by comparing it to inactive placebo or to other established osmotic laxatives. Researchers monitored specific outcomes related to physical discomfort, including the weekly frequency of bowel movements, measurements of stool consistency, and patient-reported outcomes describing perceived discomfort related to straining. Studies monitored measurements of bowel movement frequency and reported patterns in stool consistency measurements during the observed periods.

Evidence for Use in Acute Faecal Impaction

Macrogol was evaluated in research settings exploring controlled evacuation of acute faecal impaction. The main outcome monitored was the rate of disimpaction measured, which tracked the clearance of the mass over a defined, short time interval. A substantial portion of the highest-quality comparative research on acute impaction was observed in the pediatric population.

Evidence for Pre-Procedural Bowel Cleansing

Macrogol was studied for use in pre-procedural bowel cleansing before diagnostic procedures like colonoscopy. Research describes patterns of measured adequacy of colon cleansing and monitored secondary outcomes related to systemic or functional imbalance, such as temporary changes in body electrolyte levels. Follow-up durations were limited in these studies, as the research focus is restricted to the procedural timeframe.

Long-Term Studies and Uncertainties

Long-term effects are not fully established, as most controlled trials have limited follow-up durations. While evidence from studies observing responses over defined time intervals up to one year exists, limited information for long-term outcomes exceeding one year is still emerging. Furthermore, data for certain groups remain insufficient, meaning the direct evidence for highly specialized or complex patient populations appears to be less extensive than for general chronic constipation.

Key Studies & References

  1. Macrogol 3350 with electrolytes (Molaxole, Movicol, Laxido) for the treatment of chronic constipation

Frequently Asked Questions (FAQ)

Common questions about Molaxole (Macrogol) (FAQ)

Q: What is the main difference between Molaxole and regular Macrogol powder?

A: The main difference is the formulation. Molaxole is a combination product that includes essential electrolytes, such as sodium and potassium salts. Regular Macrogol powder without these added electrolytes is also available, but the salts in Molaxole are included to help maintain the body's normal fluid and salt balance during the osmotic process.

Q: How quickly does Molaxole typically start working after the first dose?

A: This medicine is an osmotic laxative, and its action is gradual. Authoritative sources indicate that Macrogol-based products typically begin to show effects within 1 to 2 days after the first dose is taken. This onset time reflects its physical mechanism of action, which works by hydrating the stool over time.

Q: Can Molaxole be taken long-term, or is it only for short periods?

A: The standard course of treatment for chronic constipation is typically limited to 2 weeks for initial use, according to official product information. However, the regulatory documentation does state that extended use may be necessary in cases of severe or resistant constipation and may require supervision by a healthcare professional.

Q: Does Molaxole make you go to the toilet immediately?

A: Molaxole is classified as an osmotic laxative, and its action is based on hydrating the stool, which takes time. It is not designed to produce an immediate effect; authoritative sources state it typically takes 1 to 2 days to begin working.

Q: Will Molaxole cause cramping or sudden urgency?

A: Common side effects listed in regulatory documents include abdominal pain and discomfort. The mechanism of action is described as promoting a regulated motility, distinguishing it from agents that rely on immediate, forced stimulation.

Q: Are there any specific foods or drinks that should be avoided when taking Molaxole?

A: Regulatory information does not advise avoiding any common foods or drinks when taking Molaxole. However, official product information states that the powder should not be mixed directly with liquids that have been thickened using starch-based food thickeners due to a physical incompatibility.

Q: Can Molaxole be mixed with juice or coffee instead of just water?

A: Official guidance indicates that after the powder is fully dissolved in the required amount of water, the resulting solution may be mixed with other beverages. These typically include fruit juice or fruit syrup, and the solution, once mixed, should be consumed immediately as per the preparation protocol.

Q: Why do some people say Molaxole tastes salty?

A: The formulation of Molaxole includes essential electrolytes (salts) such as Sodium Chloride and Potassium Chloride. These salts are necessary for maintaining fluid balance and contribute to the taste of the reconstituted solution, which some people perceive as salty.

Q: Can I take Molaxole if I have irritable bowel syndrome (IBS)?

A: Official regulatory documents for Macrogol-based products do not list Irritable Bowel Syndrome (IBS) as an absolute reason to avoid the medicine. However, the product is prohibited for use when severe inflammatory conditions of the intestinal tract, such as Crohn's disease or ulcerative colitis, are present.

Q: How often can I expect to have a bowel movement when using Molaxole?

A: When taken for chronic or maintenance use, official guidance often describes the intended outcome as promoting a soft, comfortable stool that is passed with a frequency of once to three times most days. This goal corresponds to normal bowel function.

Q: Are there different strengths or formulations of Molaxole available?

A: The official product information specifies that Macrogol powder is available in at least two different strengths. These include the adult strength (13.72 g) and a specific, lower paediatric strength (6.86 g) intended for use in children under 12 years of age.

Q: Is Macrogol addictive or can it create dependency if used regularly?

A: Macrogol-based treatments rely on a physical, osmotic action in the gut. This mechanism is distinct from the chemical stimulation used by older laxatives, which were sometimes associated with concerns regarding dependency.

Q: Can elderly patients use Molaxole without special concerns?

A: Regulatory dosing guidance lists the same dose for adults, adolescents, and the elderly. However, official warnings note special considerations for patients with impaired cardiovascular function receiving high doses, who may require specific monitoring.

Q: Can taking too much Molaxole cause dehydration?

A: Taking an excessive amount of Molaxole may cause severe diarrhoea, as noted in product information regarding overdose. Severe diarrhoea, in turn, can lead to temporary fluid loss and potential disturbance of the body's electrolyte balance.

Q: Is Molaxole known to interact negatively with blood pressure medication?

A: Regulatory warnings indicate the potential for the absorption of any co-administered oral medicine to be temporarily reduced due to the increased rate of intestinal transit. This caution applies to all oral medications taken near the time of Molaxole dosing, including blood pressure medication.

Q: What should I do if I accidentally miss a dose of Molaxole?

A: According to patient information, the general guidance advises taking it as soon as it is remembered. The next dose should then be taken at the usual scheduled time. Official guidance advises against taking a double dose to make up for the forgotten one.

Q: Does Molaxole need a prescription, or can it be bought over the counter?

A: The regulatory classification of Macrogol products can vary by region. In some jurisdictions, the product may be classified as a product subject to medical prescription, while in others, it may be available over the counter. This status depends on the local drug regulatory authority.

Q: What is the expected color or consistency of the mixed Molaxole solution?

A: The Molaxole powder itself is described in regulatory documents as a white crystalline powder often with a specific odour. When properly dissolved in water, the solution is intended to be a clear liquid.

Q: Why is the active ingredient called Macrogol and sometimes Polyethylene Glycol (PEG)?

A: The active ingredient has two common names. Macrogol is the official pharmaceutical name, known as the International Non-proprietary Name (INN). Polyethylene Glycol (PEG) is the chemical name for the same synthetic polymer substance.

Q: Can Molaxole be used to prevent constipation rather than just treating it?

A: The formal indications for Molaxole listed in regulatory documents are for the treatment of chronic constipation and for the resolution of faecal impaction. The product is not officially indicated for the prophylactic prevention of constipation.

Q: Does Molaxole lose its effectiveness over time if used continually?

A: Research has examined the use of Macrogol for long-term treatment. Its physical mechanism of action, which is not dependent on nerve stimulation, suggests that its effectiveness is likely to be maintained over time.

Q: Can I take other laxatives while I am using Molaxole?

A: Authoritative guidance generally indicates that only one laxative is usually sufficient for relief. Therefore, the concurrent use of two different laxative types is generally only recommended under the guidance of a healthcare professional.

Q: Can Molaxole interact with common supplements like iron or vitamins?

A: Regulatory warnings note the potential for the absorption of any co-administered oral medicine to be temporarily reduced due to the faster transit rate caused by Molaxole. The general caution regarding absorption applies to oral medicines, which includes supplements, vitamins, and minerals.

Q: Is it necessary to drink extra water when taking Molaxole?

A: The Molaxole powder must be mixed with the required amount of water for the solution to be prepared correctly. Regulatory documents do not include a specific instruction or recommendation to drink additional water beyond the volume required for reconstitution.

Q: What are the documented signs of taking too much Molaxole?

A: The documented signs of taking too much Molaxole are primarily related to effects in the digestive tract. These include severe diarrhoea and potential disturbance of the body’s electrolyte balance, which are the main risks noted in overdose warnings.

Q: How long does it take for the bloating side effect to usually go away?

A: Common side effects related to the digestive tract, such as flatulence and abdominal discomfort (bloating/distension), are generally described in patient information as being mild and transient. These effects often resolve during the initial phase of treatment.

Q: Can I take Molaxole if I have a history of electrolyte imbalance?

A: Regulatory warnings specify that patients with pre-existing impaired cardiovascular function or kidney problems require close monitoring of electrolyte levels. This is particularly important when using the high-dose faecal impaction regimen.

Q: Can Molaxole interfere with birth control pills?

A: Authoritative sources confirm that Macrogol does not affect the effectiveness of birth control pills or any other type of hormonal or non-hormonal contraception.

Q: Does the brand name Molaxole have different ingredients than other Macrogol brands?

A: The core combination of Macrogol 3350 and the essential electrolytes is a standard formulation shared across several brands in this medicine class. However, differences may exist in the excipients (non-active ingredients) used by different manufacturers.

How should Molaxole (Macrogol) be stored and disposed of?

Storage and Disposal Requirements for Molaxole

To maintain its stability, the unopened Molaxole powder for oral solution must be stored in its original package to protect it from moisture, and the temperature must remain below 25 C. The product must be kept out of the sight and reach of children.

Once the powder is mixed with water, the resulting solution must be kept covered and stored in the refrigerator (between 2 C and 8 C). The prepared solution must not be frozen and should be discarded if not used within the prescribed stability period (typically 6 to 24 hours, depending on the formulation).

Expired or unused Molaxole must be disposed of according to official guidelines. It should not be thrown away via wastewater or household trash. Patients should consult a pharmacist or local authority for information on approved pharmaceutical take-back programs.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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