The Sunlight Experiment

Compound Monograph

Beta-sitosterol

Beta-sitosterol — one of the most abundant plant sterols (phytosterols), structurally similar to cholesterol, best characterised for inhibiting cholesterol absorption in the gut.

Work in progress

Classification

Beta-sitosterol is a phytosterol, part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.

Terpenoids Sterols & Steroids

Where Does It Come From? (38)

Beta-sitosterol is a naturally occurring phytosterol, found in Saw Palmetto, Tribulus, Astragalus and 35 other sources. It is well tolerated orally (low toxicity).

African Dream Herb Entada rheedii Amaranth Amaranthus blitum Arjuna Terminalia arjuna Ashwagandha Withania somnifera Astragalus Astragalus membranaceus Avocado Bacopa Bacopa monnieri Black Ant Polyrhachis spp. Blue Lotus Flower Nymphaea caerulea Calamus Acorus calamus Cat's Claw Uncaria tomentosa Catuaba Trichilia catigua Chickweed Stellaria media Damiana Turnera diffusa Eleuthero Root Eleutherococcus senticosus Globe Artichoke Cynara scolymus Iris Iris versicolor Kid Ginseng Pseudostellaria heterophylla Maca Lepidium meyenii Milk Thistle Silybum marianum Muira Puama Ptychopetalum olacoides Nuts and seeds Passionflower Passiflora incarnata Pumpkin seedPygeum Reishi Ganoderma lucidum Sarsaparilla Smilax spp. Saw Palmetto Serenoa repens Shatavari Asparagus racemosus Slippery Elm Ulmus fulva SoySoybeans and other vegetable oils Stevia Stevia rebaudiana Stinging Nettle Urtica dioica Suma Pfaffia paniculata Tribulus Tribulus terrestris Wild Lettuce Lactuca virosa Wireweed Sida acuta

Research & Evidence

Beta-sitosterol is a phytosterol — a plant analogue of cholesterol — and is one of the most widely distributed sterols in the plant kingdom. Across the herbs in this database it appears as a constituent of the sterol fraction rather than as the single active principle, so most of what the source monographs report concerns the whole plant or its sterol-rich fraction.

  • Cholesterol absorption — its best-characterised action. In the context of Pfaffia paniculata (suma), beta-sitosterol and stigmasterol are described as inhibiting cholesterol absorption, which in turn mildly lowers plasma cholesterol concentrations 1Reference 1Masami Oshima et al. · 2003AnimalPfaffia paniculata-induced changes in plasma estradiol-17β, progesterone and testosterone levels in mice. This phytosterol effect is part of why suma’s high-saponin, sterol-containing profile is associated with an anti-cholesterol spectrum of activity 1Reference 1Masami Oshima et al. · 2003AnimalPfaffia paniculata-induced changes in plasma estradiol-17β, progesterone and testosterone levels in mice.
  • Phytosterol of sterol-rich tonics — beta-sitosterol is the principal phytosterol of the saw palmetto berry’s liposterolic extract, the fraction most associated with its use in benign prostatic hyperplasia 2Reference 2Bone K · 2013Principles and Practice of Phytotherapy. The clinical effects studied for saw palmetto (5-alpha-reductase inhibition, improvement in BPH symptoms) are attributed to that whole liposterolic extract rather than to isolated beta-sitosterol 2Reference 2Bone K · 2013Principles and Practice of Phytotherapy.
  • Constituent of adaptogenic and tonic herbs — beta-sitosterol is reported among the sterols of tribulus 3Reference 3Chhatre S et al. · 2014Phytopharmacological overview of Tribulus terrestrisView study →, astragalus, eleuthero, bacopa 4Reference 4Bacopa monniera · 2004ReviewAlternative Medicine Review: A Journal Of Clinical Therapeutic, 9(1), 79-85, milk thistle, maca, catuaba 5Reference 5Maria M et al. · 2005Antidepressant-like effects of Trichillia catigua (Catuaba) extract: evidence for dopaminergic-mediated mechanisms and others, generally documented as part of each plant’s phytochemistry rather than as a separately-studied active.

Because the source herb pages treat beta-sitosterol as a co-occurring constituent rather than an isolated drug, this page is deliberately kept modest. The references below are the entries from those pages that genuinely pertain to the sterol; the section will grow if compound-specific research is added.

Toxicity & Safety

Beta-sitosterol is a normal component of a plant-based diet and is well tolerated. None of the source herb monographs flag it as toxic. As with dietary phytosterols generally, the main considerations are mild and gastrointestinal. Where it occurs in herbs with their own cautions — for example tribulus, which the monograph advises using carefully alongside liver disease, ulcers or digestive disorders, and avoiding long-term in therapeutic doses 3Reference 3Chhatre S et al. · 2014Phytopharmacological overview of Tribulus terrestrisView study → — those cautions belong to the whole herb, not specifically to its sterol content.

References

  1. Masami Oshima, and Yeunhwa Gu. (2003). Pfaffia paniculata-induced changes in plasma estradiol-17β, progesterone and testosterone levels in mice. Journal of Reproduction and Development. 49. 2. 175-180.
  2. Bone K, Mills S. (2013). Principles and Practice of Phytotherapy. Elsevier Health, China.
  3. Chhatre S, Nesari T, Somani G, Kanchan D, & Sathaye S. (2014). Phytopharmacological overview of Tribulus terrestris. Pharmacognosy Reviews, 8(15), 45-51. doi:10.4103/0973-7847.125530
  4. Bacopa monniera. Monograph. (2004). Alternative Medicine Review: A Journal Of Clinical Therapeutic, 9(1), 79-85.
  5. Maria M. Campos, Elizabeth S. Fernandes, Juliano Ferriera, Adair R. S. Santos, Joao B. Calixto. (2005). Antidepressant-like effects of Trichillia catigua (Catuaba) extract: evidence for dopaminergic-mediated mechanisms. Phytopharmacology. 182. 45-53.