Alli Side Effects
In clinical studies, common side effects of Alli included stomach pain, gas, oily spotting, and diarrhea. Fortunately, side effects can be controlled (if not avoided altogether) by watching the amount of fat you eat. Most people tolerate the drug without problems. Contact your healthcare provider immediately if you experience serious side effects, such as kidney stones, severe stomach pain, or signs of an allergic reaction.
An Introduction to Alli Side Effects
As with any medicine, side effects are possible with Alli™ (orlistat); however, not everyone who takes the drug will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Alli. Your healthcare provider can discuss a more complete list of Alli side effects with you.)
Common Side Effects of AlliAlli is a non-prescription weight loss drug. With prescription medications, the manufacturers must provide "prescribing information" that includes detailed information about side effects. However, such information is not available for most non-prescription medications, including Alli.
Based on information submitted to the U.S. Food and Drug Administration (FDA) in order for Alli to be approved, the following side effects were commonly reported in clinical studies:
- Abdominal pain (stomach pain) -- in up to 20.1 percent of people
- Fecal urgency (an urgent but controlled need to have a bowel movement) -- up to 18.8 percent
- Gas -- up to 18.6 percent
- Oily spotting (uncontrolled anal oil seepage) -- up to 17.7 percent
- Gas with a small amount of oil or stool -- up to 17.2 percent
- Fatty or oily stool -- up to 17.2 percent
- Diarrhea -- up to 11.9 percent
- Oily evacuation (bowel movements of just oil, without stool) -- up to 11.6 percent
- Sinus infection -- up to 10.6 percent
- Soft stool -- up to 10.1 percent.
Other common side effects of Alli (occurring in 3 to 10 percent of people) included:
- Increased frequency of bowel movements
- Uncontrolled, spontaneous bowel movements (known as fecal incontinence)
- Back pain.
Many of these problems that affect the digestive tract can be avoided or reduced by decreasing the amount of fat in your diet. Because Alli decreases the absorption of fat, more fat stays in the digestive tract, causing many of the bothersome (and sometimes embarrassing) side effects. You are more likely to experience these side effects if you eat too much fat. As you continue to take the medication, you will learn how different foods and different amounts of fat will affect you. If you have consumed a meal that is high in fat and have taken Alli, you may want to prepare for possible negative effects.