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Drug side effects

polyethylene glycol 3350 Side Effects

The reactions most often reported to the FDA for polyethylene glycol 3350 (also sold as MiraLAX), with demographics, serious outcomes, and reporting trends.

Data updated 2026-05-15

91,655
FAERS reports

Data from the FDA Adverse Event Reporting System (FAERS), 2002 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.

The most commonly reported side effects of polyethylene glycol 3350 come from 91,655 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.

This page analyzes 91,655 reports to the FDA Adverse Event Reporting System (FAERS) for polyethylene glycol 3350 (MiraLAX): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.

Total Reports

91,655

Reports Mentioning Death

6,093

6.6% of reports — not proof the medicine caused the death

Hospitalizations

20,647

22.5% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

DIARRHOEA
6,828
NAUSEA
5,306
CONSTIPATION
5,098
FATIGUE
4,564
VOMITING
3,284
PAIN
2,927
INCORRECT DRUG ADMINISTRATION DURATION
2,837
INCORRECT DOSE ADMINISTERED
2,725
DEATH
2,717
DYSPNOEA
2,703
HEADACHE
2,657
ASTHENIA
2,622
DIZZINESS
2,434
ABDOMINAL PAIN
2,419
INCORRECT PRODUCT ADMINISTRATION DURATION
2,310
FALL
2,276

Who Reports Side Effects

Gender Distribution

Female 50,437 (61%)
Male 32,645 (39%)
Unknown 255

Age Distribution

0-17 5,550 (11%)
18-44 4,908 (9%)
45-64 11,918 (23%)
65-74 11,803 (23%)
75+ 17,576 (34%)

Reporting Trend by Year

2002 2025

Reactions in Death Reports

Top reactions reported in 6,093 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 2,711
NAUSEA 525
SEPSIS 477
CONSTIPATION 461
VOMITING 434
PNEUMONIA 421
DYSPNOEA 420
ANAEMIA 380
FATIGUE 360
ABDOMINAL PAIN 355
ASTHENIA 352
GENERAL PHYSICAL HEALTH DETERIORATION 303
RESPIRATORY FAILURE 277
ABDOMINAL DISTENSION 269
FALL 268
ASCITES 262
CARDIAC ARREST 262
HYPONATRAEMIA 262
PAIN 259

Reactions in Hospitalization Reports

Top reactions in 20,647 reports where hospitalization was an outcome.

Reaction Reports
NAUSEA 1,945
PNEUMONIA 1,756
CONSTIPATION 1,672
FATIGUE 1,571
VOMITING 1,571
DYSPNOEA 1,507
FALL 1,423
DIARRHOEA 1,373
ASTHENIA 1,326
PAIN 1,275
PYREXIA 1,268
ABDOMINAL PAIN 1,188
URINARY TRACT INFECTION 1,091
ANAEMIA 1,084
DEHYDRATION 1,000
WEIGHT DECREASED 924
HEADACHE 848
SEPSIS 812
DIZZINESS 811

Compare polyethylene glycol 3350 vs alosetron →

What the FAERS Data Reveals About polyethylene glycol 3350 Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 91,655 voluntary reports linked to polyethylene glycol 3350 and its brand equivalents (MiraLAX), spanning 2002 through 2025. Of those, 6,093 (6.6%) listed death as an outcome and 20,647 (22.5%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 61% were female and 39% male; age distribution skews toward 75+, with 17,576 reports in that bracket. The single most reported reaction is diarrhoea with 6,828 submissions, followed by nausea and constipation.

How to read these numbers

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.

Drugs With a Similar FAERS Report Volume

Other medications with a total FDA adverse-event report count closest to polyethylene glycol 3350's 91,655.