Polyethylene Glycol 3350

Medically reviewed by Drugs.com. Last updated on Apr 16, 2025.

Excipient (pharmacologically inactive substance)

What is it?

Polyethylene glycol, referred to as PEG, is used as an inactive ingredient in the pharmaceutical industry as a solvent, plasticizer, surfactant, ointments, and suppository base, and tablet and capsule lubricant. PEG has low toxicity with systemic absorption less than 0.5%.

PEGylation occurs when PEGs are attached to various protein medications, allowing for greater solubility for certain drugs. Examples of PEGylated medications include PEG-interferon alpha (Pegintron) and PEG-filgrastim (Neulasta). PEG is also available as a bowel prep for colonoscopy procedures and as a laxative.^[1]

PEG 400 indicates the average molecular weight of the specific PEG at 400.^[2] PEG 3350 is a laxative available over-the-counter by the name of Miralax. In this case, PEG is considered an "active" ingredient, even though systemic absorption is less than 0.5%.

Some examples of medications containing Polyethylene Glycol 3350

• Aleve naproxen sodium 220 mg
• Amoxicillin Trihydrate 875 mg
• Amoxicillin Trihydrate 500 mg
• Cetirizine Hydrochloride 10 mg
• Descovy 200 mg / 25 mg
• Famotidine 40 mg
• Famotidine 20 mg
• Gabapentin 600 mg
• Glipizide Extended-Release 10 mg
• Levetiracetam 500 mg
• Metformin Hydrochloride 500 mg
• Metformin Hydrochloride 1000 mg
• Metoprolol Tartrate 25 mg
• Metronidazole 250 mg
• Metronidazole 500 mg
• Nifedipine Extended-Release 30 mg
• Risperidone 1 mg
• Sildenafil Citrate 20 mg (base)
• Sildenafil Citrate 100 mg
• Valsartan 160 mg

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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