Beta-sitosterol is a phytosterols (plant sterol) with chemical structure similar to that of cholesterol. Beta sitosterol inhibits cholesterol absorption in the intestine. It can be found in many plants such as Nigella sativa, pecans, Saw palmetto (Serenoa repens), etc. Beta sitosterol is incorporated in margarine, yogurt, or other foods .
What are the benefits of beta sitosterol?
Beta-sitosterol is commonly used for treating benign prostatic hyperplasia [2,3] and high-cholesterol .
In bodybuilding world Beta-sitosterol is used in many testosterone enhancers due to its possible effect in 5-alpha reductase inhibition [3,5]. As testosterone levels increase so does dihydrotestosterone (DHT – more active form). DHT is generated by a 5-alpha reduction of testosterone . DHT is the primary contributing factor in male pattern baldness .
Prager N. et al.  have shown the effectiveness of Saw palmetto (Serenoa repens) and beta-sitosterol, as naturally occurring 5-alpha reductase (5AR) inhibitor, against male pattern baldness (androgenetic alopecia). This pilot study showed highly positive effects. 60% of the subjects treated were rated as improved after final check.
Beta-Sitosterol side effects
Plant sterols are generally recognized as safe when consumed at the recommended doses and no major side effects are noted. However, there is a concern that it may reduce absorption of fat-soluable vitamins carotenes and vitamin E (no effect noted on Vitamin A and K) .
- Matsuoka, Keisuke, et al. “Study of thermodynamic parameters for solubilization of plant sterol and stanol in bile salt micelles.” Chemistry and physics of lipids 154.2 (2008): 87-93.
- Berges, R. R., A. Kassen, and T. Senge. “Treatment of symptomatic benign prostatic hyperplasia with β‐sitosterol: an 18‐month follow‐up.” BJU international 85.7 (2001): 842-846.
- Berges, R. R., et al. “Randomised, placebo-controlled, double-blind clinical trial of β-sitosterol in patients with benign prostatic hyperplasia.” The Lancet 345.8964 (1995): 1529-1532.
- Becker, M., D. Staab, and K. Von Bergmann. “Long-term treatment of severe familial hypercholesterolemia in children: effect of sitosterol and bezafibrate.” Pediatrics 89.1 (1992): 138-142.
- Cabeza, Marisa, et al. “Effect of beta-sitosterol as Inhibitor of 5alpha-reductase in Hamster Prostate.” Proceedings-Western Pharmacology Society. Vol. 46. [Western Pharmacology Society]; 1998, 2003.
- http://www.hmdb.ca/metabolites/hmdb02961 Retrieved 6. Jan 2013
- “Male Pattern Baldness Causes”. Hair Loss Health Center. WebMD, LLC.
- Prager, Nelson, et al. “A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-α-reductase in the treatment of androgenetic alopecia.” The Journal of Alternative & Complementary Medicine 8.2 (2002): 143-152.
- Retrieved from Drugs.com at 20. May 2013