Mineral

    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

    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

    Beauty
    Insufficient evidence
    Limited

    Silica appears in beauty supplements with minimal supporting human evidence.

    Skin Health Enhancement

    Beauty
    Mixed evidence
    Moderate Evidence
    Effectiveness 3/5

    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 Research
    7 studies

    Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin

    Score: 6/10
    2005
    rct
    n=50

    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.

    View source

    Vitamins and minerals: their role in nail health and disease

    Score: 6/10
    2007
    systematic_review

    Scheinfeld N, Dahdah MJ, Scher R

    A 10-mg dose of silicon daily, a useful form of which is choline-stabilized orthosilicic acid.

    View source

    Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair

    Score: 6/10
    2007
    rct
    n=48

    Wickett RR, Kossmann E, Barel A

    ch-OSA supplementation improved hair tensile strength and thickness in women with fine hair.

    View source

    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

    Score: 7/10
    2008
    rct
    n=136

    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.

    View source

    Dietary silicon intake is positively associated with bone mineral density in men and premenopausal women of the Framingham Offspring cohort

    Score: 6/10
    2004
    cohort
    n=2847

    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.

    View source

    Dietary silicon interacts with oestrogen to influence bone health: evidence from the Aberdeen Prospective Osteoporosis Screening Study

    Score: 6/10
    2012
    cohort
    n=3198

    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.

    View source

    Silicon: a review of its potential role in the prevention and treatment of postmenopausal osteoporosis

    Score: 5/10
    2013
    systematic_review

    Price CT, Koval KJ, Langford JR

    Silicon is a promising but unproven adjunct for bone health; more controlled trials are needed.

    View source

    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: insufficient_data

    Breastfeeding: insufficient_data

    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.

    Forms Compared

    Best absorbed and only form with positive human RCTs for skin, hair, nails

    Traditional source; contains thiaminase — avoid raw/long-term high doses

    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.