Most patients who take beta sitosterol will not experience any side effects. Others may experience mild side effects that are usually limited to gastrointestinal discomfort. Patients with certain preexisting conditions, however, can experience serious side effects that can lead to or aggravate heart disease. As with any medication, an allergic reaction is one of the possible side effects of beta sitosterol and requires prompt medical treatment.
The most common side effects affect the patient's digestive system and usually only occur in patients who take more beta sitosterol than doctors recommend. These effects can include cramping, indigestion, excessive gas, and nausea. Patients may also experience either constipation or diarrhea as a result of taking this supplement. Vomiting is not generally seen with the use of beta sitosterol, though patients who are prone to vomiting may do so at the onset of nausea. For the most part, patients who do experience these possible side effects are not seriously troubled by them and continue to take the supplement as prescribed.
Men can also experience sexual side effects of beta sitosterol. This supplement has been known to decrease the sex drive and cause erectile dysfunction. These symptoms go away when the patient stops taking beta sitosterol and are not generally a cause for concern, especially if the patient is taking this supplement for only a short period of time.
Beta sitosterol may also compromise a patient's ability to absorb both vitamin E and carotenes. These side effects of beta sitosterol can cause neurological problems or long-term health complications. Both of these possible effects are due to the vitamin deficiency rather than the beta sitosterol itself and can be corrected by taking supplemental vitamin E and A. Patients can also eat foods rich in these vitamins to prevent deficiencies.
Rarely, serious allergic reactions can occur as side effects of beta sitosterol. Signs of allergic reaction include rash or hives, swelling on the face or in the mouth, difficulty breathing, and a change in the heart rate or blood pressure. Patients with these symptoms need to see a doctor immediately so that the allergic reaction can be treated.
It is also possible for patients with sitosterolemia to experience adverse side effects of beta sitosterol. In these patients, beta sitosterol can lead to heart disease or exacerbate a preexisting heart condition. This happens because patients with sitosterolemia already have too much beta sitosterol in their bodies, which can clog the arteries and damage the heart.