Silica Supplement
Also known as: silicon dioxide, orthosilicic acid, OSA, bamboo silica, horsetail silica, biogenic silica, silicon
Effective Dosage
No established dose
What the Science Says
Silica is a naturally occurring mineral compound (silicon dioxide) found in foods like oats, barley, and horsetail plant. It is often marketed for supporting hair, skin, nails, and bone strength, based on silicon's role in connective tissue formation. The only published research available involves a novel silica supplement tested in broiler chickens, where it improved bone mineral density and breaking strength — but no human clinical trials have been conducted to confirm these effects in people.
What It Doesn't Do
No proven benefit for hair growth or thickness in humans — that's marketing, not science. No clinical evidence it strengthens nails or improves skin elasticity. Not proven to support joint health in people. Animal results do not automatically translate to humans. Don't assume 'natural' means safe at high doses.
Evidence-Based Benefits
A novel pH-neutral, monomeric form of silicon supplement demonstrated higher in vitro bioavailability compared to other commercial silicon supplements, and in broiler chickens showed increased blood silicon levels, higher tibia ash content, and significantly greater tibia breaking strength compared to bamboo-derived silicon (PMID: 30451899). These findings suggest potential applications for bone integrity support, though all evidence is currently limited to animal models.
Weak EvidenceEffective at: No established dose (insufficient research data)
Source: auto-research
Absorption & Bioavailability
Variable — highly dependent on the form. Orthosilicic acid (OSA) is generally considered more bioavailable than silica from plant sources like bamboo or horsetail. One animal study found a novel monomeric form had significantly higher blood uptake than bamboo-derived silica. Human absorption data is limited.
Red Flags to Watch For
- No human clinical trials exist in the provided research — all bone-related findings come from broiler chicken studies
- Silica form matters enormously for absorption, but most supplement labels don't specify the bioavailable form
- High-dose silicon dioxide inhalation is a known occupational hazard (silicosis); oral supplement safety at high doses is not well characterized
- Over 1,000 registered supplement products contain silica, yet the clinical evidence base is essentially nonexistent
- Marketing claims about hair, skin, and nails far outpace the actual science
Research Sources
- General knowledge
- PMID: 30451899 — animal bioavailability study in broiler chickens (Scientific Reports, 2018)
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-06