Overview
Beta-sitosterol is a plant-derived phytosterol structurally similar to cholesterol, used primarily for its cholesterol-lowering effects through inhibition of intestinal cholesterol absorption. It's classified as a nutraceutical/dietary supplement rather than a prescription drug in most jurisdictions.
Mechanism of Action
Competitively inhibits intestinal absorption of dietary and biliary cholesterol by displacing cholesterol from mixed micelles in the intestinal lumen. This reduces cholesterol transport into enterocytes, leading to increased fecal excretion of cholesterol and decreased serum LDL cholesterol levels.
Indications
- Dietary management of hypercholesterolemia
- Benign prostatic hyperplasia (BPH) symptom relief
- Adjunct in cardiovascular risk reduction
Dosage
Typically 130-300 mg taken 2-3 times daily with meals. For cholesterol management: 800-6000 mg daily in divided doses. For BPH: 60-130 mg daily. Always follow product-specific labeling.
Contraindications
- Hypersensitivity to beta-sitosterol or related phytosterols
- Sitosterolemia (phytosterolemia)
- Pregnancy (unless specifically recommended by healthcare provider)
Side Effects
- Gastrointestinal disturbances (nausea, diarrhea, constipation)
- Reduced absorption of fat-soluble vitamins
- Headache
- Erectile dysfunction (rare)
- Allergic reactions
Interactions
- Cholesterol-lowering drugs (additive effects)
- Fat-soluble vitamin supplements (reduced absorption)
- Ezetimibe (theoretical interaction via similar mechanism)
- Orlistat (may reduce efficacy)