Beta-Sitosterol Health & Wellness Serenoa repens [Saw Palmetto]

Beta-Sitosterol: 5-alpha reductase inhibitor, reduces cholesterol (LDL)

Beta-sitosterol is a phytosterols (plant sterol) with chemical structure similar to that of cholesterol. Beta sitosterol inhibits cholesterol absorption in the intestine.[1] 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 [9].

What are the benefits of beta sitosterol?

Beta-sitosterol is commonly used for treating benign prostatic hyperplasia [2,3] and high-cholesterol [4].

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 [6]. DHT is the primary contributing factor in male pattern baldness [7].

Prager N. et al. [8] 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) [9].


  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. Retrieved 6. Jan 2013
  7. “Male Pattern Baldness Causes”. Hair Loss Health Center. WebMD, LLC.
  8. 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.
  9. Retrieved from at 20. May 2013