Hello, It does not contain animal by-products. MiraLax (Polyethylene glycol) is an osmotic laxative used for the symptomatic relief of constipation and also to evacuate the bowel prior to the endoscopic examination of the colon. The only one ingredient polyethylene glycol is a petroleum-derivative that is made from ethylene glycol the main ingredient in antifreeze. It is not an animal by-product. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Mohammed Taher Ali