Skip to content
My WebMD Sign In, Sign Up

Weight Loss & Diet Plans

Font Size

Alli: Everything You Need to Know

Side Effects of Alli

Loose stools and other bowel movement changes are the most common side effects of Alli. Symptoms typically occur during the first few weeks of treatment and then go away. However, they may continue.

Tell your doctor if you have any of the following symptoms and they become severe or do not go away:

  • Difficulty controlling bowel movements
  • Loose, frequent stools
  • Oily or fatty stools
  • Oily spots on undergarments
  • Stomach or rectum pain
  • Passing gas more often
  • Urgent need to have a bowel movement
  • Anxiety
  • Changes in your menstrual cycle
  • Headaches

Emergency Side Effects of Alli

Call your doctor or 911 immediately if you develop any of these symptoms:

  • Difficulty breathing
  • Difficulty swallowing
  • Hives or itching
  • Stomach pain that is severe or does not go away

Alli has been linked to severe liver injury in rare cases, though it has mostly occurred in those taking the prescription-strength dose (Xenical). Stop taking Alli and call your doctor immediately if you develop any of these possible signs of liver damage:

  • Dark urine
  • Fatigue
  • Fever
  • Light-colored stools
  • Loss of appetite
  • Severe, persistent itching
  • Weakness
  • Vomiting
  • Yellowing of the skin or eyes (jaundice)
1|2

WebMD Medical Reference

Reviewed by Kimball Johnson, MD on October 13, 2012

Today on WebMD

measuring waist
4 tips for shedding yours.
apple cider vinegar
Does it have health benefits?
 
Chocolate truffle
For weight loss, some aren’t so bad after all.
woman holding red dress
24 simple, practical tips.
 
woman shopping fresh produce
Video
butter curl on knife
Quiz
 
eating out healthy
Article
Smiling woman, red hair
Article
 
thumbnail_woman_tossing_spinach
Video
lunchbox
Article
 
What Girls Need To Know About Eating Disorders
Article
teen squeezing into jeans
fitfor Teens
 

Special Sections