Silica
Silicon dioxide / orthosilicic acid
TL;DR
Silica shows modest signals for hair, skin and nail quality and possible bone benefits, but most evidence is small, short or industry-funded. Choline-stabilized orthosilicic acid (ch-OSA) is the best-studied form.
Ideal For
- People with brittle nails or thinning hair seeking adjunct support
Avoid If
- Chronic kidney disease
- Pregnancy (horsetail forms)
Frequently Asked Questions
What is silica used for?
Does it improve hair and nails?
What about bone density?
What dose is used?
Does the form matter?
Is it safe?
Overview
Silicon is the second most abundant element in the earth's crust, but dietary silicon (as silica or silicic acid) is only weakly absorbed. Interest centres on its role in collagen and glycosaminoglycan synthesis in skin, hair, nails and bone. The strongest data come from small trials of choline-stabilized orthosilicic acid (ch-OSA), which improved skin elasticity, hair strength and nail brittleness over 20 weeks, and from cohort data linking higher dietary silicon intake to greater bone mineral density. Most other silica supplements (horsetail extract, colloidal silica) lack rigorous human data.
How It Works
- Supports collagen cross-linking via prolyl hydroxylase activity
- Stimulates osteoblast differentiation and bone matrix formation
- Concentrates in skin, hair and nail keratin structures
Quick Facts
- Best-studied form: choline-stabilized orthosilicic acid (ch-OSA)
- Typical studied dose: 6-10 mg elemental silicon/day
- Found naturally in beer, whole grains and green beans
Benefits & Outcomes
Skin Hydration
Silica appears in beauty supplements with minimal supporting human evidence.
Skin Health Enhancement
One good RCT line exists for ch-OSA specifically, but single-group, industry-linked evidence keeps this at mixed.
Health Concerns Addressed
No linked health concerns yet.
Supporting Research7 studies
Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin
Barel A, Calomme M, Timchenko A
Oral ch-OSA had a positive effect on skin surface and mechanical properties and on brittleness of hair and nails.
Vitamins and minerals: their role in nail health and disease
Scheinfeld N, Dahdah MJ, Scher R
A 10-mg dose of silicon daily, a useful form of which is choline-stabilized orthosilicic acid.
Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair
Wickett RR, Kossmann E, Barel A
ch-OSA supplementation improved hair tensile strength and thickness in women with fine hair.
Choline-stabilized orthosilicic acid supplementation as an adjunct to calcium/vitamin D3 stimulates markers of bone formation in osteopenic females: a randomized, placebo-controlled trial
Spector TD, Calomme MR, Anderson SH
ch-OSA had a potentially beneficial effect on bone collagen formation, but no significant BMD effect was demonstrated over 12 months.
Dietary silicon intake is positively associated with bone mineral density in men and premenopausal women of the Framingham Offspring cohort
Jugdaohsingh R, Tucker KL, Qiao N +3 more
Higher silicon intake was associated with significantly higher hip BMD in men and premenopausal women, but not in postmenopausal women.
Dietary silicon interacts with oestrogen to influence bone health: evidence from the Aberdeen Prospective Osteoporosis Screening Study
Macdonald HM, Hardcastle AC, Jugdaohsingh R +3 more
No overall association between silicon intake and BMD; a positive association appeared only in oestrogen-replete women.
Silicon: a review of its potential role in the prevention and treatment of postmenopausal osteoporosis
Price CT, Koval KJ, Langford JR
Silicon is a promising but unproven adjunct for bone health; more controlled trials are needed.
Safety Information
Potential Side Effects
Generally well tolerated. Horsetail-derived silica can cause thiamine depletion with long-term use; ensure thiaminase-free products.
Contraindications
Kidney disease (silicate stones reported with excessive intake); horsetail forms in pregnancy or thiamine deficiency.
Pregnancy & Breastfeeding
Pregnancy: Not enough evidence to judge
Breastfeeding: Not enough evidence to judge
Dosage Guidelines
Dosage Used in Studies
6-10 mg silicon
Best Form
Choline-stabilized orthosilicic acid
Bioavailability
Low for most forms; ch-OSA achieves the highest documented absorption.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| Typical | 6-10 mg elemental silicon daily | ch-OSA dosed by elemental silicon content, not compound weight |
Forms Compared
Choline-stabilized orthosilicic acid (ch-OSA)
Best absorbed and only form with positive human RCTs for skin, hair, nails
Horsetail extract (standardized silica)
Traditional source; contains thiaminase — avoid raw/long-term high doses
Colloidal silica / bamboo extract
Poorly characterized absorption; little human data
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.