Microlax Macrogol

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Microlax Macrogol

Method of action: Laxative

Treatment option:

Medically reviewed

Marina Burgos

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 Microlax Macrogol

Property Description
Active ingredient Macrogol (Polyethylene Glycol, PEG)
Form Powder for oral solution, liquid
Pharmacological class Osmotic laxative
Common use Alleviating general constipation
Origin Synthetic polymer

What Type of Medicine is Macrogol?

Microlax Macrogol is a medicine containing the active ingredient Macrogol, which is chemically identified as Polyethylene Glycol (PEG). It is classified as an osmotic laxative, a category of drugs that address symptoms of general constipation by utilizing physical action rather than direct muscle stimulation. Macrogol is an osmotic agent designed to treat chronic constipation. This mechanism is clinically recognized for providing effective relief across various patient demographics, establishing Macrogol as a primary choice in managing difficult or infrequent bowel movements.

Composition and Origin: Unique Features of Macrogol

Macrogol is a synthetic polymer derived from ethylene glycol, meaning it is manufactured and not obtained from natural sources. It is recognized as a biologically inert substance. Macrogol is non-absorbable from the gastrointestinal tract, ensuring its effects are localized to the gut. This property simplifies management by focusing the action entirely on the bowel contents, distinguishing it from agents absorbed systemically. The substance’s inert nature and favorable tolerance profile make Macrogol highly suitable for use in patient groups such as older adults who require predictable, gentle relief. It is typically supplied as a single-ingredient product, often in the form of a powder for oral solution.

What is the General Therapeutic Purpose of Macrogol?

The core function of Macrogol is to improve the physical characteristics of stool through osmotic action. Once ingested, the substance effectively attracts and retains water in the bowel, which significantly increases the luminal volume and creates a softer, bulkier stool mass. The general therapeutic purpose is to facilitate comfortable, non-straining bowel movements, thereby managing the primary symptom of constipation. This gentle mechanism, which provides relief without stimulating the intestinal muscles, is widely accepted for its efficacy in resolving general constipation cases.

What side effects are possible with Microlax Macrogol?

Possible Side Effects and Safety Information

Adverse reactions to Macrogol (Polyethylene Glycol) are officially documented in regulatory sources and primarily relate to the gastrointestinal system, consistent with its osmotic action. Side effects are classified by frequency, ranging from common to very rare.


Adverse Reaction Classification

The majority of effects fall under Gastrointestinal disorders (System-Organ Class).

Classification Documented Effects
Common Abdominal pain, bloating, distension, flatulence, nausea, and diarrhoea. These effects are often transient and more frequently reported at the start of treatment.
Uncommon Vomiting, urgency to defecate, and fecal incontinence.
Very Rare Severe hypersensitivity reactions, including anaphylaxis, angioedema, rash, and urticaria, categorized under Immune System disorders.

Serious Adverse Reactions and Restrictions

The label documents the potential for severe hypersensitivity and significant fluid and electrolyte abnormalities (such as low sodium or potassium) associated with high doses or prolonged use, falling under Metabolism and Nutrition disorders.

Safety Restrictions and Limitations formally prohibit the use of Macrogol in certain conditions. It must not be used in cases of known or suspected intestinal obstruction (ileus), gastrointestinal perforation or risk of perforation, severe inflammatory bowel disease (e.g., toxic megacolon), or abdominal pain of unknown cause.


Population-Specific Safety Notes

The official safety profile includes specific considerations for patient groups. Older adults may have a higher documented incidence of diarrhoea and require consideration for fluid and electrolyte balance during extended use. For pediatric use, the safety and effectiveness for over-the-counter use in younger children are not established in all regulatory contexts. The need for professional consultation is noted for patients with impaired renal function.

Overdose and Emergency Response

Overdose: When to Seek Help

Overdose with macrogol (Polyethylene Glycol 3350) is primarily associated with pronounced gastrointestinal effects due to its osmotic action.

Documented Overdose Presentations

The most commonly expected symptom following an excessive dose is diarrhea or excessive stool frequency. This can lead to extensive fluid loss and, in the absence of adequate fluid intake, may result in dehydration and electrolyte disturbances. In cases involving oral formulations with electrolytes, severe presentations can include intense abdominal pain or distension.

Overdose and Emergency Action

Official regulatory information emphasizes that if an overdose is suspected, immediate medical attention is required. Patients should get medical help or contact a Poison Control Center right away.

Required clinical actions for severe cases, as outlined in regulatory documents, may include measures to correct electrolyte imbalances following extensive fluid loss from vomiting or diarrhea. Severe abdominal pain or distension may necessitate nasogastric aspiration as a management step.

Overdose risk is specifically noted for high doses in certain populations, such as elderly nursing home patients, who may be more susceptible to excessive stool frequency.

Therapeutic Uses of Microlax Macrogol

Macrogol (Polyethylene Glycol) is generally used for symptomatic relief across key domains of bowel dysfunction, and may help support comfortable bowel movements. Polyethylene Glycol 3350 is commonly used to help with symptoms related to occasional constipation and may assist with managing symptoms related to physical discomfort.


Key Therapeutic Applications and Symptom Management

The agent is relevant in conditions where symptoms may intensify temporarily, such as functional constipation, or conditions involving episodic or fluctuating manifestations. The agent may assist with secondary constipation, such as that induced by opioid pain medications, and is relevant in clinical settings that involve the management of severe stool accumulation, or fecal impaction. Macrogol helps address symptom clusters that create noticeable physiological strain, such as straining and symptoms related to physical discomfort, offering short-term symptomatic assistance when symptoms become more noticeable. This contributes to improved comfort during periods of heightened symptoms.


Supporting Vulnerable Patient Contexts

The agent is commonly used to help with functional stress in relevant patient groups, including children and older adults, who may experience chronic symptoms. This supports the patient during difficult episodes by easing distress.

Quick Fact: Relief for Straining and Hard Stools


Regulatory References

  1. Polyethylene Glycol 3350: NIH MedlinePlus Drug Information

Eligibility and Restrictions for Use

Who Can and Cannot Use Microlax Macrogol?

Population eligibility for Macrogol (Polyethylene Glycol) is strictly defined by regulatory documents, focusing on patient age and underlying gastrointestinal conditions.

Absolute Contraindications

Use is prohibited for patients with: intestinal obstruction, ileus, bowel perforation or risk of perforation, toxic megacolon, and severe inflammatory bowel conditions like Crohn’s disease or ulcerative colitis. Patients with a known hypersensitivity to Macrogol must also not use the medicine.

Age and Physiological Status

Adults and adolescents (typically 12 years and older) are generally approved for use. However, the use of standard adult formulations is not recommended for children under 12, as safety and effectiveness in the younger pediatric population are often not established by regulatory agencies.

Pregnancy and breastfeeding are generally permitted statuses for Macrogol use because regulatory data indicates systemic exposure is negligible, meaning effects on the fetus or infant are not anticipated. For patients with impaired cardiovascular function undergoing treatment for faecal impaction, the label advises a conditional restriction: no more than two sachets in any one hour should be consumed. Patients with renal impairment typically require no dose adjustment.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile of Macrogol (Polyethylene Glycol) is primarily defined by its physical action in the gastrointestinal tract rather than systemic metabolic activity, as it is a non-absorbable substance.

Pharmacokinetic and Timing Interactions

Macrogol's osmotic action increases the speed of intestinal transit. This change is classified as a pharmacokinetic interference that may lead to the transiently reduced absorption and decreased efficacy of certain co-administered oral medicines.

  • Specific Risk: Decreased exposure has been documented for drugs, including Digoxin. Furthermore, regulatory bodies note isolated reports of reduced efficacy when Macrogol is co-administered with Anti-epileptics (Anticonvulsants).
  • Timing Rule: To mitigate the risk of reduced absorption, official guidance advises that other oral medicines should not be taken for one hour before and one hour after Macrogol administration.

Pharmacodynamic and Product Interactions

  • Starch-based Food Thickeners: Macrogol may cause a pharmacodynamic interaction by counteracting the thickening effect of starch-based food products, causing liquefaction. Mixing with these thickeners is generally advised against.
  • Population Note: This interaction with thickeners poses an increased risk of aspiration for patients with dysphagia (swallowing problems), a population-specific caution noted in regulatory guidance.

Mechanism of Action

Osmotic Modulation and Intraluminal Fluid Dynamics

The primary mechanism of Macrogol involves its function as a large, non-absorbable polymer that acts as a physical agent, primarily targeting free water molecules within the gastrointestinal lumen. The molecule creates a high osmotic gradient that draws water from the body's circulation (extracellular fluid) into the colon. This action significantly increases the liquid volume, which is a mechanism fundamentally different from those relying on direct receptor-mediated signaling or neurotransmitter modulation.


Fecal Hydration and Motility Regulation

The mechanical consequence of this fluid retention is the hydration and reduction of density of the solid fecal matter. By increasing the volume and fluidity of the intestinal contents, the drug changes the physical properties of the stool. The resulting large, soft bulk causes a physiological distension of the colonic wall, which mechanically activates the intrinsic myenteric nerve plexus, leading to a functional stimulation of peristalsis (wave-like muscle contractions) that provides the propulsive force.

Dosage and Administration Information

How to Use Macrogol

Macrogol (Polyethylene Glycol or PEG) is an osmotic laxative administered through the oral route as a powder for solution. The drug's usage is defined by specific quantitative and temporal schedules established for the management of bowel symptoms.


Dosing and Administration Schedules

Feature Instruction Summary
Standard Dosing (Adult) For general constipation, regimens typically involve 17 g once daily or 1 to 3 sachets daily (approximately 13 g to 39 g). High-dose regimens for faecal impaction may utilize up to 8 sachets daily for a short course.
Frequency and Timing Macrogol is generally taken once daily or in divided doses throughout the day. Administration can be taken with or without food.
Preparation The powder must be fully dissolved in a specific volume of liquid (such as water) prior to ingestion. The solution should not be consumed if undissolved clumps are present.
Treatment Duration Use for occasional constipation is typically limited to 7 days, while chronic constipation therapy may be extended beyond 2 weeks with dose adjustment. Faecal impaction courses normally do not exceed 3 days.

Population and Procedural Rules

There is typically no dosage change required for older adults or individuals with renal or hepatic impairment. The protocol for a missed dose is to not double the dose, but to resume the standard schedule at the next scheduled time. These instructions formalize the procedural use of the medicine.

Recent Clinical Evidence

Research evidence / Overview of studies for Microlax Macrogol

Evidence for use in Chronic and Functional Constipation

Randomized Controlled Trials (RCTs) and Systematic Reviews have focused on Macrogol’s use in managing common, chronic, and functional constipation. Research examined outcomes like the mean number of Spontaneous Bowel Movements (SBMs) per week and objective measurements of stool consistency in diverse populations, including both adults and children. Trials report patterns related to changes in the frequency of SBMs in the observed groups compared to those receiving a placebo. Findings suggest specific patterns related to stool consistency measurements compared to other standard therapies. What remains uncertain is the extent of comparative evidence for evaluating different formulations.


Evidence for use in Fecal Impaction

Research has explored Macrogol’s role in the acute management and resolution of severe stool accumulation. Studies, including RCTs, have compared protocols using Macrogol against alternative procedures, monitoring physiological strain and the measurements of impaction change. Research highlights changes measured during the study period, indicating that Macrogol protocols were associated with outcomes measured relative to alternative procedures. Data for maintenance protocols following successful disimpaction often involve observational cohorts rather than long-term, randomized comparisons.


Research into Constipation Associated with Irritable Bowel Syndrome (IBS-C)

Placebo-controlled trials have examined Macrogol’s role for the constipation component of IBS-C, focusing on SBM frequency and outcomes related to physical discomfort, such as abdominal pain. Findings indicate patterns related to changes in SBM frequency and changes in stool consistency measurements during the study period compared to placebo. However, when research examined the associated symptom of abdominal pain or discomfort, studies report that measured outcomes were often comparable between the treatment group and the placebo group. Research describes that the findings apply predominantly to the constipation component of the syndrome.


Long-Term Studies and Follow-Up Data

Research has described Macrogol usage that extends over defined time intervals, with some studies monitoring responses for up to one year. Data show patterns related to monitored measurements of bowel movements in the observed populations. Despite these observations, certainty remains low when evaluating use for periods beyond 12 months. Therefore, long-term data on daily-life functioning extending beyond one year are not fully established.


Evidence in Special Populations

Macrogol was evaluated in studies focusing on pediatric populations and older adults. Research describes trials exploring short-term symptom changes and impaction resolution protocols in children. However, data for certain groups remain insufficient. Comparative evidence for Macrogol in the context of older adults or severe comorbidity remains insufficient.


What is Still Uncertain About Macrogol Research

Evidence quality varies across studies, and in some key trials, sample sizes were modest. Follow-up durations were often limited, meaning long-term effects are not fully established. Comparative evidence is lacking for certain formulations and against certain standard comparators across all age groups. Therefore, evidence highlights what is known—and what is still uncertain—about Macrogol's research profile.

Key Studies & References Polyethylene Glycol 3350: NIH MedlinePlus Drug Information

Frequently Asked Questions (FAQ)

Common questions about Microlax Macrogol (FAQ)


Q: Is Microlax Macrogol considered a bulk-forming or an osmotic laxative?

Regulatory documents and official product information describe Macrogol (Polyethylene Glycol) as an osmotic laxative. Official documents describe the mechanism as drawing water into the bowel, which contributes to softer, bulkier stool. This action is different from the way bulk-forming laxatives operate.


Q: How quickly do people generally expect Microlax Macrogol to start working?

Patient information commonly cited by regulatory bodies indicates that the effect of Macrogol is not immediate. It may take two to four days to produce a bowel movement. This time frame reflects the gradual mechanism by which Macrogol works to hydrate the stool contents.


Q: Can Macrogol cause dependency if used regularly?

Official information states that Macrogol works by acting on the water content of the stool, not on the nerves or muscles of the gut. For this reason, it is generally not described in official documents as causing dependence or tolerance.


Q: What are the signs that suggest Macrogol might not be working for someone?

General patient information advises that if symptoms of constipation persist or worsen despite following the standard use instructions, consultation with a healthcare professional may be necessary. The official documents define the maximum duration of use before professional advice is required.


Q: Why is adequate fluid intake mentioned when discussing Macrogol use?

Macrogol is an osmotic agent that works by drawing water from the body's circulation into the colon. Regulatory guidance for osmotic agents notes that maintaining adequate fluid intake is described as important to support the osmotic action and prevent volume-related effects.


Q: Does Macrogol help prevent future episodes, or only treat existing constipation?

Macrogol is officially indicated for the treatment of chronic and occasional constipation. While research has examined its use for maintenance following the resolution of severe impaction, its primary, formal indication per labeling is focused on treating existing symptoms.


Q: Can people with kidney problems use Microlax Macrogol?

Due to its minimal absorption into the bloodstream, regulatory information indicates that Macrogol typically does not require a dose adjustment for people with impaired kidney function. However, official safety notes advise that Macrogol is used with caution in patients with pre-existing kidney problems or electrolyte disturbances.


Q: Is it described in official sources whether Macrogol is absorbed into the body?

Official sources, including the NIH literature, state that Macrogol is a non-absorbable substance from the gastrointestinal tract. This means the substance remains primarily in the gut, ensuring its effects are localized to the bowel contents.


Q: Can I use Microlax Macrogol if I have Irritable Bowel Syndrome (IBS)?

Official information acknowledges that research has explored Macrogol's role for the constipation component associated with Irritable Bowel Syndrome (IBS-C). Patients with pre-existing or severe inflammatory bowel conditions are advised to use laxatives with caution.


Q: Can Macrogol be used alongside pain relievers like ibuprofen?

Official guidance advises that taking Macrogol can increase the speed of intestinal transit, which might lead to the reduced absorption of other oral medicines. For this reason, other oral medicines should not be taken for one hour before and one hour after Macrogol administration.


Q: Can Macrogol be mixed with juice or other beverages?

Yes. Official instructions require the powder to first be fully dissolved in the correct volume of water. The resulting liquid may then often be mixed with or further diluted into other standard beverages such as juice, coffee, tea, or soda, depending on the specific product leaflet.


Q: Does Macrogol have a taste, and are there different flavor options available?

Macrogol powder is generally described as having a mild taste in its unflavored form. Official products, depending on the specific formulation and manufacturer, are commonly available in a range of different flavor options, such as chocolate, orange, or lemon/lime.


Q: Is the preparation liquid meant to be taken hot or cold?

Official preparation instructions do not typically specify a required temperature for the liquid used for mixing. Patient guidance notes that the prepared solution can be chilled in the fridge before taking it to improve the taste.


Q: What is the recommended period of time to use Macrogol before seeing a doctor?

Regulatory treatment duration limits are typically 7 days for occasional use in the US, and up to two weeks for chronic constipation in the EU. Consultation with a healthcare professional is described as generally necessary if symptoms persist or worsen beyond the defined duration of use.


Q: Can Microlax Macrogol affect the absorption of certain vitamins or supplements?

The osmotic action of Macrogol increases intestinal transit time, which can transiently reduce the absorption and effectiveness of co-administered oral medicines. Official advice describes the importance of informing a doctor or pharmacist about any supplements or vitamins being taken due to this potential for reduced absorption.


Q: Is Microlax Macrogol suitable for people who are sensitive to certain sugars?

The suitability depends on the specific inactive ingredients (excipients) in the product. Regulatory documents for certain Macrogol formulations contain warnings regarding the presence of sweeteners or sugars (such as Sorbitol or Sucrose) for patients with related intolerances or metabolic conditions.


Q: Can Microlax Macrogol affect blood sugar levels for diabetics?

Macrogol is a non-absorbable polymer. However, patients with conditions like diabetes are generally advised to use the product with caution. Certain specific formulations may contain sugars or electrolytes that could require attention depending on the patient's specific metabolic and dietary conditions.


Q: How is the safety profile of Macrogol generally described in official sources?

Official sources generally describe the safety profile of Macrogol as well tolerated in adults and children. Adverse reactions are primarily limited to the gastrointestinal system, such as bloating and diarrhea, and these effects are often transient.


Q: Is Macrogol typically described as gentle on the stomach?

While the term 'gentle' is non-clinical, Macrogol is officially characterized as a biologically inert substance with a non-stimulant mechanism of action. The reported side effects are mostly gastrointestinal and often transient, consistent with its non-stimulant mechanism of action.


Q: Why is the drug sometimes called PEG 3350 in the US and Macrogol in Europe?

Macrogol and Polyethylene Glycol (PEG) refer to the chemically identical active ingredient. 'Macrogol' is the name commonly used in European pharmacopoeias and regulatory contexts, while 'Polyethylene Glycol' or 'PEG 3350' is widely used in the United States and international regulatory documents.


Q: Do official materials mention any potential for allergic reactions to Macrogol?

Yes. Regulatory documents and official patient materials describe the potential for very rare severe hypersensitivity reactions. These reactions, which can include anaphylaxis, angioedema, rash, and hives, are categorized under Immune System disorders.


Q: Are there any documented drug interactions with common anti-depressants?

General interaction guidance notes that certain oral medications, including medicines for depression, may not work as effectively if taken at the same time as Macrogol. This is because Macrogol can increase intestinal transit speed, potentially reducing the absorption of co-administered drugs.


How should Microlax Macrogol be stored and disposed of?

How to Store and Dispose of Macrogol (Polyethylene Glycol)

Storage of Macrogol powder and the reconstituted solution is defined by specific regulatory temperature and handling requirements.


Storage Conditions

  • Unmixed Powder: Store at controlled room temperature, below 25 C (77 F), in the original, tightly closed container to protect it from moisture and heat. Do not use the powder after the expiry date.
  • Reconstituted Solution: The prepared liquid must be refrigerated (2 C to 8 C) and must not be frozen. Any unused solution must be discarded within 6 to 24 hours, depending on the specific formulation.

Safety and Disposal

The medication must be kept out of sight and reach of children at all times. Unused or expired Macrogol products, including mixed solution that passes the time limit, must be disposed of in accordance with local requirements established by health authorities, often by returning it to a pharmacist.

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

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