Your Side Effects May IncludeXenical side effects
orlistat
This side effect is printed on the FDA label for Xenical. It was a question in our daily quiz, where you pick the real side effect from four choices.
Oily spotting and leaks you can't control
The fat you don't absorb has to go somewhere. The label is very specific about where.
“Most common treatment emergent adverse reactions (≥5% and at least twice that of placebo) include oily spotting, flatus with discharge, fecal urgency, fatty/oily stool, oily evacuation, increased defecation and fecal incontinence.”
A low-fat diet cuts these effects. Take a multivitamin as directed, since Xenical blocks some vitamins.
1,869 reports to the FDA's adverse event system mention oily stool, leakage or loss of bowel control. A report is not proof the drug caused it. See the query
From quiz No. 4 · September 28, 2026 · Play that quiz →
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Not medical advice. Don't stop or start a medication because of a quiz. Talk to your doctor or pharmacist. Label text and report counts from openFDA. Not affiliated with any drug maker.