GlycoLax

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GlycoLax

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Method of action: Laxative

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 GlycoLax

Quick Facts

Property Description
Active Ingredient Macrogol (Polyethylene Glycol or PEG)
Form Powder for oral solution
Pharmacological Class Osmotic laxative
Common Use Relief of general constipation
Origin Synthetic polymer

GlycoLax is an orally administered medication classified as a gastrointestinal agent designed for the relief of general constipation. The product is typically presented as a single-ingredient, non-stimulant laxative that works through physical principles within the digestive tract. The foundational component, Macrogol, is listed in pharmacopeias, establishing its safety profile.

What Type of Medicine is GlycoLax?

GlycoLax belongs to the pharmacological class of osmotic laxatives, agents defined by their capacity to retain water within the bowel lumen. This classification confirms that the medicine works by drawing water into the colon. The drug is distinct from stimulant varieties because its effect is based on physical chemistry, not on chemically inducing muscular contractions in the bowel wall. Macrogol is a widely used first-line option for this purpose.

Composition and Form: Macrogol as an Oral Powder

The sole active ingredient in GlycoLax is Macrogol, scientifically referred to as Polyethylene Glycol (PEG), which is a synthetic polymer. This material is neither absorbed by the body nor metabolized, meaning its entire function is concentrated in the intestinal tract. As an effective treatment for constipation in adults and children, it supports the general relief of bowel discomfort. It is most commonly supplied as a powder for oral solution or an oral powder, intended to be dissolved in an aqueous vehicle (liquid) before being taken orally.

Core Purpose and Non-Stimulant Action

The core purpose of GlycoLax is to normalize the consistency of stool by leveraging the physical principle of osmosis. Macrogol molecules draw water from the surrounding tissues into the colon, significantly increasing the water content of the fecal matter. By achieving this essential water retention, the medication ensures the stool is softer and bulkier, which aids in a natural and gentler process for relieving general constipation without chemically stimulating the bowel muscles.

What side effects are possible with GlycoLax?

Possible Side Effects and Safety Information

Adverse drug reactions (ADRs) associated with Macrogol (Polyethylene Glycol or PEG) are predominantly related to the Gastrointestinal System, though systemic reactions are also documented in regulatory sources.

Adverse Reaction Frequency and System Organ Class

The most commonly reported effects are digestive, as summarized in official labeling:

System Organ Class (SOC) Adverse Reaction Frequency Classification
Gastrointestinal Disorders Diarrhoea Very Common (ge 1/10)
Abdominal pain, Flatulence, Nausea, Vomiting, Abdominal distension Common (ge 1/100 to < 1/10)
Immune System Disorders Hypersensitivity reactions (e.g., rash, pruritus, urticaria) Uncommon
Metabolism and Nutrition Electrolyte disorders (Hypokalaemia, Hyponatraemia), Dehydration Uncommon

Frequency classifications (Very Common, Common, Uncommon, etc.) are based on regulatory standards and reflect reported rates.


Serious Adverse Reactions and Safety Constraints

Regulatory documents highlight the potential for severe hypersensitivity reactions, including anaphylaxis and angioedema. Electrolyte imbalances, particularly with prolonged or excessive use, are documented and may lead to other serious consequences like arrhythmias in vulnerable patients.

Contraindications: Macrogol is not to be used in individuals with severe existing bowel conditions, including known or suspected Gastrointestinal (GI) obstruction (Ileus), Bowel perforation, Toxic colitis/megacolon, or severe Inflammatory bowel diseases (e.g., Crohn's disease, Ulcerative colitis). Use is also restricted in cases of known hypersensitivity to Polyethylene Glycol.

Population Safety Notes: Older adults may be more susceptible to electrolytic disorders from diarrhoea and require attention. In cases of renal impairment, use is generally not recommended unless medically supervised due to potential for increased systemic exposure.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdosage of GlycoLax (Macrogol) is formally documented to result from excessive osmotic action, which may lead to severe diarrhea, vomiting, and intense abdominal cramping. The core risk is the development of significant fluid loss and secondary electrolyte disturbances (such as hyponatremia and hypokalemia) resulting from this over-activity. Overdose manifestations may escalate to systemic effects including extreme thirst, confusion, and potentially a seizure if severe fluid and chemical abnormalities are not addressed. Patients with pre-existing kidney disease or those susceptible to electrolyte imbalances must exercise particular caution, as they are at higher risk for severe outcomes in overdose.

Regulatory guidance explicitly states that if more than the recommended dosage is taken, patients must get medical help or contact a Poison Control Center right away. Urgent medical attention is required, and emergency services must be called if the affected individual has collapsed, experienced a seizure, or has trouble breathing. If symptoms like diarrhea or abdominal pain worsen substantially, use of the product should be discontinued immediately. Treatment is limited to symptomatic and supportive care, with an emphasis on correcting the resultant fluid and serum chemistry abnormalities, as no specific antidote is known.

Therapeutic Uses of GlycoLax

What GlycoLax Treats: Main Uses and Benefits

GlycoLax (Macrogol) is commonly used to address symptoms related to physical discomfort and conditions characterized by recurrent or episodic manifestations. Relevant contexts include both occasional constipation and the long-term management of chronic idiopathic constipation. The primary therapeutic benefit is that it supports the management of hard stool consistency and associated excessive straining. This effect may assist with maintaining functional stability and a more consistent bowel pattern. The medication is also applied in addressing more intense symptomatic periods such as faecal impaction.

It is considered relevant when supportive symptom management is appropriate across different patient groups, including adults, older adults, and children (in appropriate formulations), and may assist in managing secondary constipation linked to other chronic illnesses. This approach contributes to easing the overall symptom load by supporting functional stability.

“This symptomatic relief generally supports a more manageable passage, helping to improve day-to-day comfort during symptomatic periods.”

Quick Fact: Relief for Hard Stool
Symptom Targeted Hard, dry stool consistency
Primary Indication Chronic and occasional constipation
Core Therapeutic Benefit Supports maintenance of a stable bowel pattern

Eligibility and Restrictions for Use

The official regulatory profile for GlycoLax (Macrogol/Polyethylene Glycol) defines eligibility by age and the presence of specific gastrointestinal conditions. Use is generally permitted for Adults and Adolescents 17 years and older (for U.S. over-the-counter use). Use in Children 16 years and under requires consultation with a healthcare professional, as safety and effectiveness in the general U.S. pediatric population is not established.


Contraindicated Populations

Use of GlycoLax is strictly contraindicated for patients with:

  • Hypersensitivity (allergy) to Macrogol.
  • Intestinal Obstruction (ileus), Perforation, or Toxic Megacolon.
  • Severe Inflammatory Bowel Diseases (e.g., symptomatic Crohn's disease or ulcerative colitis).

Conditional Eligibility and Restrictions

  • Pregnancy and Breastfeeding: Use is generally permitted because systemic absorption is negligible, but professional consultation is advised by regulatory agencies.
  • Impaired Organ Function: Patients with kidney disease or impaired hepatic function should use the medicine only under the advice of a doctor due to the risk of electrolyte imbalance.
  • Dysphagia Risk: The medicine should not be mixed with starch-based thickeners as this may counteract the thickening effect, potentially increasing aspiration risk.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official regulatory profile for Macrogol (the active ingredient in GlycoLax) is defined by its action as a non-absorbed osmotic laxative. Consequently, the medicine is not metabolized, and regulatory documentation confirms the absence of officially documented metabolic (CYP) or drug transporter-mediated interactions.

The majority of interactions documented by government authorities are physical in nature and relate to the medicine’s effect on the gastrointestinal tract.

Documented Interaction Patterns

Classification Official Regulatory Statement
Pharmacodynamic Interference Co-administration of Macrogol may cause a reduction in the systemic exposure and therapeutic effect of other oral medicinal products. This is due to the increased rate of gastrointestinal transit, which reduces the time available for absorption.
Timing Restriction When Macrogol is used at a high dose for bowel cleansing, regulatory labels advise that oral medications administered within one hour of starting the solution may be purged and unabsorbed.
Physical Incompatibility Co-mixing with starch-based food thickeners is advised against. Macrogol can counteract the thickening effect, causing liquefaction. This action carries an officially noted increased risk of aspiration for patients with swallowing problems (dysphagia).

These official statements structure the product’s interaction profile, which focuses on the risk of reduced absorption of co-administered oral drugs and a specific caution regarding physical incompatibility with certain food substances.

Mechanism of Action

How GlycoLax Works

Mechanism of Osmotic Action

The mechanism of action for GlycoLax, containing Macrogol (Polyethylene Glycol), is classified as physicochemical; it works locally within the gastrointestinal lumen and is entirely independent of binding to classical biological targets like receptors or enzymes. The mechanism is centered on altering colonic fluid dynamics and influencing physical bulk modulation.

Macrogol is an inert, non-absorbed polymer that creates an extremely high osmotic pressure within the intestinal lumen. By forming multiple hydrogen bonds with water molecules, Macrogol sequesters the water, creating a counter-osmotic gradient that overrides the natural physiological reabsorptive gradient. This action contributes to the hydration of the fecal mass.

Physiological Cascade

The resulting increased volume and bulk of the hydrated fecal material directly cause mechanical distension (stretching) of the colon wall. This physical stretching secondarily activates the peristaltic reflex, a natural physiological response that initiates the smooth muscle contractions required to propel the contents forward. The combined physiological effects of increased water content and secondary motility result in the propulsion of the material.

Dosage and Administration Information

How GlycoLax Is Used: Administration Guidelines

GlycoLax (Macrogol) is a medicine administered orally as a powder for oral solution, requiring the product to be fully dissolved in a liquid vehicle before ingestion. The general principle of usage is structured around specific dosing, preparation requirements, and time-bound limits for various approved applications.

Standard Dosing and Frequency

The adult dosing is based on the intended use. For occasional constipation, the standard adult and adolescent (17 years) dose is 17 grams taken once daily. For the management of chronic constipation, regimens of 1 to 3 sachets daily (e.g., 13.7 g strength) are used, often taken in divided doses. In cases of faecal impaction, a specialized, high-dose regimen of up to 8 sachets daily may be followed, typically consumed within a 6-hour period.

Administration Requirements

Feature Procedural Guideline
Preparation The powder must be completely dissolved in 4 to 8 ounces of liquid (water, juice, soda, coffee, or tea).
Timing The dose can be taken with or without food.
Course Duration Use for occasional constipation should not exceed seven days unless directed by a clinician. Treatment for faecal impaction typically does not exceed three days.
Special Constraint The product must not be mixed with starch-based food thickeners, as this may counteract the thickening properties.

Population-Specific Rules

No dosage adjustment is generally necessary for the use of Macrogol in older adults or in patients with renal impairment. If a dose is missed, the next dose is taken at the usual scheduled time, skipping the missed dose, with caution against doubling the dose.

Recent Clinical Evidence

Research Evidence / Overview of Studies for GlycoLax


Evidence for Use in Chronic and Functional Constipation

Research examining Macrogol for chronic or functional constipation relies on numerous short-term Randomized Controlled Trials (RCTs) and Systematic Reviews in both adults and children. These studies explored outcomes like the frequency of spontaneous bowel movements (SBMs) and changes in stool consistency. The data show patterns related to a higher measured frequency of bowel movements in the Macrogol groups compared to placebo. Regulatory evidence assigned a High level to the data observing these core outcomes.


Evidence for Use in Fecal Impaction

For fecal impaction, comparative trials was evaluated in pediatric patients and adults, monitoring the proportion of patients meeting the criteria for successful disimpaction. These short-term studies reported high proportions of patients meeting the clearance criteria. Regulatory evidence assigned a Moderate to High level to the data observing the resolution criteria, although certainty can remain low due to varying criteria definitions across older research.


Evidence for Use in Occasional (Short-Term) Constipation

Studies focusing on occasional constipation include short-term, placebo-controlled trials in adults over approximately one week. These trials monitored patient-reported outcomes, such as the complete resolution of symptoms and reduction in straining. Research provides insight into short-term changes, with regulatory evidence assigning a High level based on the results of the key placebo-controlled trials.


Long-Term Data and Research Gaps

While some extension studies have been observed for up to six months or one year, long-term outcomes are not fully established, which may be associated with factors like participant drop-out. A key limitation is the heterogeneity (variability) observed across Macrogol studies, where formulations and comparators often differed significantly. Subgroup findings are uncertain for some populations, as data for certain groups remain insufficient.

Key Studies & References MedlinePlus Drug Information: Polyethylene Glycol 3350

Frequently Asked Questions (FAQ)

Common questions about GlycoLax (FAQ)


Q: How long does it typically take for GlycoLax to start working?

A: Official product information indicates that the medicine generally produces a bowel movement in 1 to 3 days after the first administration. This typical onset time reflects the period needed for the osmotic process to fully hydrate the stool.

Q: Is there a specific time of day that GlycoLax is usually recommended?

A: Official instructions state that the medicine is taken once daily. The timing is flexible, as the dose can be taken with or without food at any time of day that is convenient for the user.

Q: What should I expect during the first few days of using GlycoLax?

A: According to official documents, the desired effect (a bowel movement) typically occurs within 1 to 3 days. Users may also experience common, temporary side effects such as nausea, bloating, cramping, or gas during the initial period of use.

Q: What is the main difference between GlycoLax and other common over-the-counter products?

A: According to regulatory classifications, GlycoLax is an osmotic laxative. This means it works by drawing and retaining water in the stool, a physicochemical process. This mechanism is different from bulk-forming laxatives (like fiber supplements) or stimulant laxatives.

Q: How does GlycoLax compare to fiber supplements in terms of mechanism?

A: The medicine is classified as an osmotic laxative that draws water into the colon to soften the stool. This is a different mechanism from fiber supplements, which are typically bulk-forming laxatives that add physical mass or bulk to the stool.

Q: Is there a risk of dependency if GlycoLax is used regularly?

A: Official product information indicates that the medicine is not associated with causing dependency or tolerance when used appropriately. This physicochemical mechanism means the effect is local, and official information suggests it is generally not associated with dependency.

Q: Can the effectiveness of GlycoLax decrease over time?

A: Official information suggests it is not typically associated with causing tolerance, meaning effectiveness is generally not expected to decrease when used as directed.

Q: What do clinical studies indicate about the safety of long-term use of GlycoLax?

A: Official product information states that the medicine is not approved for use beyond seven days for occasional constipation. Regulatory evidence notes that long-term outcomes are not fully established, although some observational studies have looked at use for several weeks to months.

Q: Do I need a doctor’s prescription to obtain GlycoLax?

A: This product is officially classified in regulatory databases as a HUMAN OTC DRUG, meaning it is available for purchase Over-the-Counter without a prescription.

Q: Can children or infants use GlycoLax?

A: The official labeling specifies use for Adults and children 17 years of age and older. Use and dosage in children younger than 17 years must be determined by a healthcare provider.

Q: What does official guidance say about using GlycoLax while pregnant or breastfeeding?

A: The official label contains a statement that a health professional should be consulted before use if a person is pregnant or breastfeeding. The systemic exposure is expected to be negligible, meaning minimal exposure to the fetus or infant is anticipated.

Q: Are there any dietary restrictions when taking GlycoLax?

A: Regulatory documents contain a specific caution advising against mixing the medicine with starch-based food thickeners. This restriction is noted because the medicine may counteract the thickening effect, which carries an officially noted risk of aspiration.

Q: Does GlycoLax interact with heart or blood pressure medications?

A: Regulatory cautions focus on the risk of reduced absorption of any oral medicine due to the increased speed of intestinal transit. Separately, official safety notes state that caution may be required for patients with pre-existing heart rhythm problems because of the potential for electrolyte disturbances from excessive use.

Q: What are the official warnings about taking GlycoLax with other over-the-counter medicines?

A: Official warnings state there is a risk of reduced absorption and therapeutic effect of any oral medicinal product when taken at the same time. The label advises consulting a health professional before use if you are taking a prescription drug.

Q: Does GlycoLax interact with common vitamins or supplements like iron or magnesium?

A: Regulatory cautions on interactions focus on the risk of reduced absorption of oral products. Some Macrogol formulas carry a warning that iron supplements may be affected by co-administration, indicating that absorption of some nutrients could potentially be affected.

Q: Is it possible to have an allergic reaction to GlycoLax?

A: Yes, the official label includes an Allergy Alert and advises against use if you are allergic to polyethylene glycol. Hypersensitivity reactions are officially listed as potential adverse reactions in regulatory documents.

Q: Are headaches listed as a common side effect of GlycoLax usage?

A: Headache is reported as a potential side effect in official documents. It is often categorized as Rare or may be linked to symptoms of dehydration if present.

Q: Can GlycoLax affect blood sugar levels, making it unsuitable for people with diabetes?

A: Studies and official information indicate that the active medicine is not significantly absorbed and is reported as not affecting blood glucose levels. However, patients with diabetes may require caution due to the risk of electrolyte imbalance from excessive use.

Q: What should be done if a child or pet accidentally ingests GlycoLax?

A: The official label contains a statement that in case of overdose or suspected accidental ingestion, medical help or contact with a Poison Control Center should be sought right away.

Q: Where is GlycoLax typically stored—at room temperature or in the refrigerator?

A: The powder should be stored at Controlled Room Temperature in a dry place. The medicine should be kept away from direct sunlight, high heat, and moisture.

Q: What is the recommended procedure for safely disposing of unused GlycoLax?

A: The recommended procedure for disposal, according to official guidance, involves mixing the leftover medicine with an unwanted material, such as used coffee grounds or kitty litter. This mixture should then be placed in a sealed container and discarded in the trash.

Q: How should GlycoLax be stored when traveling to maintain its effectiveness?

A: To maintain effectiveness, the medicine should be stored at room temperature and kept in its original container. Avoid exposing it to extreme heat or moisture, which can occur during travel.

Q: What information is available regarding the expiration date of GlycoLax powder?

A: Official guidance states that the medicine should not be used after the expiration date printed on the container, as the quality and effectiveness may degrade.

Q: Does the powder form dissolve completely or leave residue in the drink?

A: Official usage guidelines state that the powder must be completely dissolved in the liquid vehicle. The guidelines advise that the liquid should not be consumed if there are any visible clumps of undissolved powder.

Q: Can GlycoLax be mixed with hot drinks like coffee or tea?

A: The guidelines for preparation state the powder must be fully dissolved in a liquid vehicle. Acceptable liquids listed in official documents include coffee or tea.

Q: Why is GlycoLax sometimes confusingly referred to as polyethylene glycol 3350?

A: The medicine's active ingredient is Macrogol (Polyethylene Glycol), and the number 3350 refers to its average molecular weight. This is a technical designation used in the full chemical name to specify the particular compound.

Q: What is the official chemical name of the active ingredient in GlycoLax?

A: The official chemical name for the active ingredient is Macrogol or Polyethylene Glycol 3350. The number 3350 indicates the specific molecular weight of the compound.

Q: What are the inactive ingredients found in GlycoLax?

A: The official label states the active ingredient is Polyethylene Glycol 3350. The product is typically described as an Unflavored Powder with no other active or inactive ingredients stated in the prescribing information.

Q: Does GlycoLax contain any artificial sweeteners or sugar?

A: Official labeling typically describes the product as Unflavored Powder and lists only Polyethylene Glycol 3350 as the active ingredient. This suggests an absence of added flavoring or sweeteners.

Q: Is there a generic equivalent to the name-brand GlycoLax available on the market?

A: The compound Polyethylene Glycol 3350 is the official generic name of the active ingredient. This compound is widely available under various brand names and as a generic product.

Q: Is GlycoLax available in different forms, such as powder versus liquid?

A: Regulatory databases specify the dosage form as a powder for oral solution. Other non-powder forms are not mentioned in the official prescribing information for this specific product.

Q: Why do people sometimes use GlycoLax for colon cleansing preparations?

A: The medicine's active ingredient, Macrogol, is noted in regulatory-linked studies for its role in Bowel preparation therapy. This is due to its strong osmotic effect, which helps cleanse the colon for procedures.

Q: Can I use GlycoLax if I have food sensitivities or allergies?

A: The official label includes an Allergy Alert for polyethylene glycol, which is a contraindication for use. Information regarding general food sensitivities (e.g., gluten) is not typically detailed in official prescribing documents.

How should GlycoLax be stored and disposed of?

The storage and disposal of GlycoLax (Polyethylene Glycol 3350 Powder for Oral Solution) must comply with specific regulatory requirements to ensure product integrity and safety.


Storage Requirements

  • Temperature: Store the powder at Controlled Room Temperature, defined as 20 C to 25 C (68 F to 77 F). Excursions are permitted up to 30 C.
  • Container Integrity: The medication must be kept in the original container and the cap must be kept tightly closed to protect the powder from moisture.
  • Child Safety: It is mandatory to keep the product out of the reach of children.

Disposal Instructions

Any GlycoLax that is outdated or no longer needed must be properly disposed of. Consumers are advised to talk to a pharmacist for guidance on the correct method for discarding unused medication.

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

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