Silica (Horsetail Extract)
Commonly used for
Bone HealthSkin, Hair & NailsHealthy Aging
Where to Buy
Our experts personally review each product we recommend for quality and cost effectiveness.
The cheapest product is usually low quality, but more expensive doesn’t always mean better.
The cheapest product is usually low quality, but more expensive doesn’t always mean better.
What is it? / Overview
Silicon appears to support collagen synthesis and matrix mineralization in bone and connective tissue -- one trial found orthosilicic acid plus calcium/vitamin D improved femoral bone density more than calcium/vitamin D alone, though standalone human RCT evidence remains limited.
How is it used? / Administration
Form: Orthosilicic acid (best absorbed) or horsetail (Equisetum) extract, standardized and certified free of the toxic Equisetum palustre species
Typical dose studied: ~6 mg/day orthosilicic acid, or ~25 mg/day silicon equivalent
Timing: With food or water
Horsetail contains thiaminase, which can degrade thiamine -- a real concern in alcohol use disorder or existing thiamine deficiency, hence that contraindication. Choose orthosilicic acid or a certified-species horsetail product.
How well does it work? / Evidence
? Emerging / limited evidence
Who should avoid it?
Avoid with: Alcohol use disorder; Chronic kidney disease (Stage 3, 4, or 5) — NOT on dialysis
Interacts with: Diuretics -- horsetail has mild diuretic-like effects, theoretical additive risk
Already taking it? Reasonable to continue if well tolerated; confirm the product is orthosilicic acid or a stabilized form rather than plain silica gel, which absorbs poorly.
Research & references
Rondanelli M et al. (2021). Silicon: A Neglected Micronutrient Essential for Bone Health. Experimental Biology and Medicine. Jugdaohsingh R (2007). Silicon and Bone Health. The Journal of Nutrition, Health & Aging. Nielsen FH (2014). Update on the Possible Nutritional Importance of Silicon. Journal of Trace Elements in Medicine and Biology.
Disclosure: Knozela is a participant in the Amazon Associates affiliate program. Some "Where to buy" links on this page are affiliate links -- if you make a purchase through them, Knozela may earn a commission at no additional cost to you.