A Study of the Potential for Polyethylene Glycol (Miralax) to Metabolize into Toxic Oxalate


About this study

The purpose of this research study is to determine if the frequent use of polyethylene glycol (MiraLAX) may cause hyperoxaluria - an abnormally high level of oxalate in the urine.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria

  • Any individual ages 18 to 65
  • Women who are post-menopausal or have had a hysterectomy will be considered eligible
  • A subject will be considered eligible if she has no signs or symptoms of pregnancy and meets any one of the following criteria:
    • Is ≤7 days after the start of normal menses
    • Has not had sexual intercourse since the start of last normal menses
    • Has been correctly and consistently using a reliable method of contraception
    • Is ≤7 days after spontaneous or induced abortion
    • Is within 4 weeks postpartum
    • Is fully breastfeeding (exclusively breastfeeding or the vast majority [≥85%] of feeds are breastfeeds), amenorrheic, and <6 months postpartum

Exclusion Criteria

  • Individuals at risk of enteric or secondary hyperoxaluria, ie have a history of 
    • Diarrhea
    • Malabsorption (Crohn’s disease, Celiac disease, history of gastric sleeve or bypass)
    • Primary hyperoxaluria
    • Use orlistat, cholestyramine or other medications known to influence fat absorption
  • Have an eGFR of below 60 mL/min/1.73m2 or a 24 hour urine oxalate level of > 0.46 mmol (the upper limit of normal per our laboratory)
  • Women will be excluded if they are pregnant or could be pregnant at the time of the study
    • Women must stop the study and notify the coordinator if there is a chance they may have become pregnant during the study 

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Dawn Milliner, M.D.

Closed for enrollment

More information


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