Silica

• Bone density support, as an adjunct to calcium and vitamin D (Spector 2008, manufacturer-funded)
• Higher dietary silicon associated with higher hip BMD (Framingham observational, not a supplement claim)
• Hair tensile strength and thickness (Wickett 2007, small ch-OSA trial)
• Skin elasticity and reduced wrinkle depth (Barel 2005, small ch-OSA trial)
• Nail strength and reduced brittleness (Barel 2005)
• Connective tissue and collagen support (mechanistic rationale)
• Mild diuretic use (horsetail folk tradition)

Silicon (chemical symbol Si) is the second most abundant element in Earth's crust after oxygen, yet its biological role in human nutrition has been characterized only since the 1970s, and its essentiality remains formally ambiguous. In humans, silicon contributes to connective tissue formation through poorly-characterized mechanisms involving collagen biosynthesis, glycosaminoglycan crosslinking, and possibly direct structural roles in connective tissue matrices. Total body silicon content is approximately 1g in a 70kg adult, distributed across connective tissues, bone, skin, hair, nails, and arterial walls. The two clinically relevant supplementation contexts involve fundamentally different chemistry: orthosilicic acid (the bioavailable monomeric form Si(OH)₄, stabilized in commercial products by choline as ch-OSA / BioSil) and silica derived from horsetail (Equisetum arvense, an ancient plant lineage from the Devonian period ~350 million years ago, with high silicon content concentrated as biogenic amorphous silica in plant tissues). These two product categories represent distinct evidence bases and consumer positioning, ch-OSA being the mineral-supplement category with the most rigorous clinical trial evidence (Wickett 2007 hair, Spector 2008 bone, Barel 2005 skin), while horsetail-derived silica represents the traditional/herbal/botanical category with longer cultural history but more limited modern clinical evidence. The biological mechanism for silicon's contribution to connective tissue is incompletely characterized but involves multiple pathways. Silicon participates in collagen biosynthesis at the prolyl hydroxylase step, though this finding remains contested in some literature. Silicon-rich diet has been associated with bone mineral density in observational cohort studies (Jugdaohsingh 2004 Framingham analysis showed positive association between silicon intake and BMD). Silicon may modulate aluminum bioavailability and toxicity, silicic acid forms complexes with aluminum reducing aluminum absorption, potentially relevant to Alzheimer's disease aluminum-toxicity hypothesis though clinical relevance debated. Silicon contributes to glycosaminoglycan crosslinking and possibly direct connective tissue matrix roles. The orthosilicic acid form (Si(OH)₄) is the bioavailable monomer absorbed in the upper gastrointestinal tract; food silicon must depolymerize to monomeric orthosilicic acid for absorption, producing the bioavailability differences between food sources (beer is a surprisingly rich bioavailable silicon source due to brewing depolymerization) and supplement sources. The choline-stabilized formulation (ch-OSA) was developed specifically to maintain the orthosilicic acid monomer in storage and delivery, without stabilization, silicic acid spontaneously polymerizes to inactive forms. Horsetail-derived silica contains amorphous silica that requires digestive depolymerization to release bioavailable orthosilicic acid, less reliable delivery but the traditional preparation form with longer cultural history.

Standard silicon supplementation centers on 5-10mg elemental silicon daily, the range used in essentially all rigorous ch-OSA clinical trials. The Wickett 2007 hair trial, Barel 2005 skin trial, and Spector 2008 bone trial all used 10mg silicon/day from ch-OSA (BioSil) for treatment durations of 20 weeks to 12 months. Treatment durations matter substantially, the connective tissue effects develop slowly over months as new collagen synthesis incorporates the silicon contribution. Take with or between meals, absorption is acceptable either way. The ch-OSA liquid formulation (typically 5-10 drops daily, providing 5-10mg silicon) is the most established dosing format; capsule and tablet formulations of ch-OSA are also available. Horsetail-derived silica dosing is less standardized given variable silicon content; typical doses are 300-900mg horsetail extract daily, with verification of silica or silicon content per serving recommended. The "10mg silicon" target is the typical evidence-based threshold; substantially higher doses produce diminishing returns and may not be supported by additional evidence. The Upper Limit (UL) for silicon has not been formally established, no documented systemic toxicity at typical supplementation doses. Dietary silicon foundation matters: beer drinkers receive substantial bioavailable silicon from brewing depolymerization; mineral water drinkers (Fiji Water, Volvic) receive silicon from water sources; whole grain and root vegetable consumers receive food silicon. The ch-OSA pharmaceutical pharmacology (verified plasma silicon level increases) supports therapeutic positioning; horsetail bioavailability is more variable based on preparation and individual digestive depolymerization. For pregnancy: avoid horsetail products specifically; stick to dietary silicon levels.

ch-OSA standard dose

5-10mg elemental silicon/day

Wickett 2007 hair trial

10mg silicon/day x 9 months

Barel 2005 skin trial

10mg silicon/day x 20 weeks

Spector 2008 bone trial

10mg silicon/day x 12 months

Horsetail extract

300-900mg/day; variable silicon content

Typical Western dietary intake

20-50mg/day silicon

Beer silicon content

~10mg per pint (high bioavailability)

Silicon-rich mineral water

15-50mg/L

• Choline-Stabilized Orthosilicic Acid (ch-OSA, BioSil)

  Rating: gold

  The dominant clinical-grade silicon supplement form. Belgian-developed (Calomme group) choline-stabilized orthosilicic acid maintains the bioavailable monomeric silicon during storage and delivery. Used in essentially all major silicon clinical trials including Barel 2005 skin, Wickett 2007 hair, Spector 2008 bone. BioSil (Bio Minerals NV) holds patents on ch-OSA technology and licenses to multiple supplement manufacturers globally. Premium pricing justified by clinical inheritance and proven pharmacology.

• Horsetail (Equisetum arvense) Extract

  Rating: good

  The traditional herbal silicon source. Equisetum arvense (common horsetail) is an ancient plant lineage from the Devonian period that accumulates substantial amorphous silica in plant tissues. Bioavailability requires digestive depolymerization to release orthosilicic acid; less reliable delivery than ch-OSA but extensive traditional use. Substantial European herbal medicine tradition. Reasonable for users preferring botanical sources.

• Bamboo Silica Extract

  Rating: good

  Bamboo (Bambusa vulgaris and related species) extracts standardized for silica content. Alternative botanical silicon source with higher silica content than many plant materials. Less clinical evidence than ch-OSA or horsetail; reasonable alternative botanical option.

• Sodium Metasilicate / Silica Gels

  Rating: caution

  Industrial silicon compounds with limited oral therapeutic application. Sodium metasilicate has alkaline pH causing GI irritation; silica gel desiccants are explicitly labeled "do not eat" for safety reasons. These are NOT pharmaceutical or supplement-grade silicon and should not be confused with proper silicon supplementation.

• Diatomaceous Earth (Food Grade)

  Rating: caution

  Diatomaceous earth contains substantial silica derived from fossilized diatom skeletons. Food-grade diatomaceous earth (DE) is consumed in some alternative health protocols. Bioavailability of silicon from DE is poor; some safety concerns about lung exposure from particulate inhalation. Limited rigorous human evidence supporting therapeutic use; the "DE for health" alternative medicine practice has substantial internet circulation but limited evidence base. Pharmaceutical-grade ch-OSA is preferred for therapeutic silicon supplementation.

• Silica from Whole Food Sources

  Rating: gold

  Dietary silicon from beer (surprisingly bioavailable due to brewing depolymerization), bananas, root vegetables, oats, whole grains, leafy greens, and water in some regions. The most reliable foundation for silicon status; typical Western diets provide 20-50mg/day silicon (with substantial variation by diet composition).

• Mineral Water (Silicon-Rich)

  Rating: gold

  Some mineral waters (particularly Fiji Water, Volvic, and select European mineral waters) provide substantial bioavailable silicon (15-50mg/L). Reasonable dietary source for users preferring water-based intake. Geographic variation in tap water silicon content also substantial.

• Combined Hair/Skin/Nail Beauty Formulations

  Rating: good

  Silicon commonly included in comprehensive hair/skin/nail formulations alongside biotin, zinc, vitamin C, and other cofactors. Mechanistically reasonable; verify silicon dose and form (ch-OSA preferred for clinical inheritance). Major beauty supplement brands offer formulations.

• Hair and nail strength (Wickett 2007 ch-OSA)

  Strength of evidence for this group: modest

  Wickett 2007 RCT of ch-OSA at 10mg silicon/day for 9 months in women with fine hair: significant improvements in hair thickness and strength. Modest effect sizes but reproducible. Reasonable component of comprehensive hair/nail nutrition; not substitute for established dermatologic treatment in severe hair loss conditions.

• Skin elasticity and photodamage (Barel 2005)

  Strength of evidence for this group: modest

  Barel 2005 RCT of ch-OSA at 10mg silicon/day for 20 weeks in women with photodamaged skin: improvements in skin elasticity, surface roughness, and marker changes. Reasonable component of comprehensive skin nutrition; effect sizes smaller than retinoids but reasonable adjunct.

• Postmenopausal bone health (Spector 2008)

  Strength of evidence for this group: modest

  Spector 2008 RCT of ch-OSA at 10mg silicon/day for 12 months in postmenopausal women with osteopenia/osteoporosis: bone collagen marker improvements and modest BMD effects. Reasonable adjunct to comprehensive bone protocol (calcium, D3, K2, exercise). Not substitute for established osteoporosis treatment in severe disease.

• Joint comfort and osteoarthritis (preliminary)

  Strength of evidence for this group: cautious

  Preliminary evidence and traditional horsetail use for joint applications. Mechanistically reasonable through connective tissue matrix support; limited rigorous clinical trial evidence. Reasonable component of joint nutrition; not standalone joint intervention.

• General connective tissue and aging

  Strength of evidence for this group: cautious

  Reasonable component of comprehensive healthy aging nutrition for users seeking connective tissue support. Effect sizes modest in healthy non-deficient users. Foundational dietary silicon (beer, mineral water, whole foods) more impactful than targeted supplementation alone.

• Aluminum toxicity concerns (specialty)

  Strength of evidence for this group: cautious

  Silicon-aluminum complex formation has been studied as potential mitigation strategy for aluminum exposure (occupational, environmental, Alzheimer's disease aluminum hypothesis). Clinical evidence remains preliminary and specialty-focused. Not established therapeutic application; coordinate with specialist for aluminum exposure contexts.

• Hair loss (severe / clinical)

  Strength of evidence for this group: cautious

  Severe hair loss (androgenetic alopecia, alopecia areata, telogen effluvium) requires dermatology coordination. Silicon supplementation reasonable adjunct to established hair loss treatment (minoxidil, finasteride, etc.) but not substitute for established intervention.

• Pregnancy and lactation

  Strength of evidence for this group: cautious

  Limited safety data for therapeutic silicon supplementation in pregnancy and lactation. Horsetail products specifically warrant avoidance during pregnancy due to traditional emmenagogue concerns and thiaminase content. Stick to dietary silicon levels during pregnancy; coordinate with OB-GYN for supplementation.

• Pediatric use

  Strength of evidence for this group: cautious

  Limited safety data in pediatric populations. Routine pediatric silicon supplementation not warranted; horsetail products specifically not appropriate for pediatric use due to nicotine traces and thiaminase concerns.

• Diuretic use

  Strength of evidence for this group: cautious

  Horsetail has mild diuretic effect. Users on prescription diuretics should coordinate with prescribing physician given additive diuretic effects. ch-OSA does not produce this concern.

• Calcium and Magnesium

  Interaction: synergy

  Comprehensive bone protocol, silicon supports collagen and matrix formation; calcium and magnesium provide mineral substrate; vitamin D3 supports calcium handling. Mechanistically integrated bone nutrition.

• Vitamin D3

  Interaction: synergy

  Vitamin D3 supports calcium absorption and bone mineralization; silicon supports the collagen matrix that calcium mineralizes into. Common combination in comprehensive bone supplementation.

• Vitamin K2

  Interaction: synergy

  K2 directs calcium to bone via osteocalcin activation; silicon supports the collagen matrix. Mechanistically complementary; common in modern comprehensive bone formulations.

• Biotin

  Interaction: synergy

  Common combination in hair/nail beauty formulations. Biotin supports keratin synthesis; silicon supports the connective tissue and matrix that hair and nails grow from. Mechanistically complementary for hair/nail outcomes.

• Collagen Peptides

  Interaction: synergy

  Mechanistically complementary, collagen peptides provide amino acid substrate for collagen synthesis; silicon supports collagen synthesis enzymatic steps and matrix formation. Common combination in connective tissue protocols.

• Vitamin C

  Interaction: synergy

  Vitamin C is cofactor for collagen synthesis enzymes (prolyl and lysyl hydroxylases); silicon may participate in similar enzymatic steps. Mechanistically complementary in connective tissue contexts.

• Diuretics (Horsetail Specifically)

  Interaction: caution

  Horsetail has mild diuretic effect; potential additive diuresis with prescription diuretics. Coordinate with prescribing physician. ch-OSA does not produce this concern.

• Thiamine (Vitamin B1) - Horsetail Concern

  Interaction: caution

  Horsetail contains thiaminase (enzyme degrading vitamin B1), though commercial preparations typically inactivate this through processing. Verify processing standards; raw horsetail or inadequately processed products could theoretically contribute to B1 deficiency with chronic use. ch-OSA does not produce this concern.

• Aluminum-Containing Antacids

  Interaction: synergy

  Silicon forms complexes with aluminum that may reduce aluminum absorption. Theoretical advantage of silicon supplementation in users on aluminum-containing antacids; clinical relevance preliminary.

• Lithium

  Interaction: caution

  Horsetail diuretic effect could theoretically affect lithium clearance and lithium levels. Coordinate with psychiatry for users on lithium. ch-OSA does not produce this concern.

Look for: explicit silicon compound form (ch-OSA / BioSil for clinical-grade; horsetail extract for botanical); elemental silicon content per serving (5-10mg silicon for clinical doses); BioSil branding for ch-OSA clinical inheritance; Equisetum arvense species specification for horsetail (NOT E. palustre); processing verification (thiaminase inactivation for horsetail); USP or NSF third-party verification; reputable manufacturer with quality control disclosure. Avoid: products without elemental silicon disclosure; horsetail products without species verification (potential E. palustre substitution); diatomaceous earth for therapeutic oral use (limited evidence, safety concerns); silica gel or industrial silica products for oral use; very high-dose horsetail products without quality verification; products from manufacturers without third-party testing disclosure.

Research published from: Sweden.

Silicon's discovery as an element came in 1824 through Jöns Jacob Berzelius in Sweden, isolating elemental silicon from silicon tetrafluoride. The element name from Latin silex (flint) reflects the abundance of silicon in stones and minerals. Silicon's nutritional role was not characterized for nearly 150 years after elemental discovery. The biological essentiality era began in 1972 with simultaneous publications by Edith Carlisle (UCLA) and Klaus Schwarz (Veterans Administration). Carlisle demonstrated silicon essentiality in chick growth and skeletal development; Schwarz demonstrated similar findings in rats. These parallel publications established silicon as candidate essential trace element in mammals, though full formal essentiality has remained elusive in human nutrition. The Belgian ch-OSA development era began in the 1990s with Bio Minerals NV developing the choline-stabilized orthosilicic acid technology. Choline stabilization prevented the spontaneous polymerization of orthosilicic acid that had limited prior silicon supplement bioavailability. Calomme and colleagues published foundational pharmacokinetic and bioavailability research through the 1990s-2000s establishing ch-OSA as the first reliable bioavailable silicon supplement form. The modern Western clinical evidence era developed substantially through ch-OSA clinical trials. Barel 2005 (Belgian skin trial), Wickett 2007 (Belgian hair trial), and Spector 2008 (UK bone trial) provided foundational ch-OSA evidence across the three commercial silicon supplement positioning categories (skin, hair, bone). The Jugdaohsingh 2004 Framingham Offspring Cohort analysis provided the foundational observational evidence connecting dietary silicon intake with bone mineral density at population scale. The horsetail tradition predates modern silicon research by millennia. Equisetum arvense has been used in European, Asian, and indigenous American traditional medicine for centuries for wound healing, urinary tract conditions, and (more recently) connective tissue support. The herb appears in traditional pharmacopoeias and in the herbal medicine traditions of multiple cultures. The thiaminase content concern emerged from livestock veterinary medicine, animals consuming horsetail in pasture developed thiamine deficiency, leading to characterization of the thiaminase enzyme. Commercial herbal preparations typically address this through processing methods that inactivate the enzyme. The Equisetum lineage itself represents one of the oldest plant lineages on Earth, the horsetail family (Equisetaceae) traces back to the Devonian period (~350 million years ago), surviving multiple mass extinctions. The high silicon content in modern Equisetum tissues reflects an evolutionary heritage from when horsetails were among the dominant plant forms on Earth. The botanical and paleontological significance has contributed to horsetail's position in traditional medicine, among the oldest plant medicines actively used. The Sripanyakorn 2009 silicon bioavailability research established the surprising finding that beer is a substantial bioavailable silicon source, brewing processes depolymerize silicon to bioavailable forms, with typical beer providing approximately 10mg silicon per pint. Mineral water silicon content (Fiji Water, Volvic, others) has substantial geographic variation; some mineral waters provide substantial daily silicon intake. The modern consumer market has seen substantial expansion of "beauty supplement" silicon products through the 2010s-2020s. BioSil-branded ch-OSA products from Natural Factors and similar dominate the premium clinical-grade segment; horsetail-derived silica products from major herbal manufacturers serve the traditional/botanical market segment. The category continues to mature; mainstream nutritional science remains more cautious about formal silicon essentiality status despite accumulating physiological evidence.

1. ~350 million years agoEquisetum lineage emerges in Devonian period
2. 1824Berzelius (Sweden) isolates elemental silicon
3. 1972Carlisle (UCLA) and Schwarz (VA) establish silicon essentiality in chicks and rats
4. 1981Carlisle bone collagen mechanism characterization
5. 1990sBio Minerals NV (Belgium) develops ch-OSA chemistry
6. 1994Calomme ch-OSA bioavailability characterization (Br J Nutr)
7. 2004Jugdaohsingh Framingham Offspring Cohort silicon-BMD
8. 2005Barel ch-OSA skin trial
9. 2007Wickett ch-OSA hair trial
10. 2008Spector ch-OSA bone trial in postmenopausal women
11. 2009Sripanyakorn comprehensive bioavailability research
12. 2014Granchi horsetail osteoblast in vitro work
13. 2010s-2020sBeauty supplement market expansion; BioSil commercial growth

• Whether silicon will gain formal essential mineral status given accumulating evidence, current "potentially essential" classification reflects evidence base position.
• Whether widely-accepted silicon status markers will emerge, current research uses dietary records or experimental low-silicon diets rather than validated clinical markers.
• Whether ch-OSA produces clinically meaningful advantages over horsetail-derived silica at equivalent silicon doses in head-to-head trials, limited direct comparison.
• Whether silicon supplementation has applications in cardiovascular health beyond the preliminary connective tissue evidence, arterial wall silicon content has been studied but clinical translation limited.
• Whether the silicon-aluminum interaction has clinical applications in occupational aluminum exposure or neurodegenerative disease contexts.
• Whether the surprising beer silicon bioavailability has implications for public health silicon nutrition, practical applications limited by alcohol content.
• Whether horsetail traditional herbal medicine evidence translates to modern Western RCT methodology, most horsetail evidence is observational or preclinical.
• Whether silicon has specific applications in nail strength versus hair growth versus skin elasticity, current evidence pools these "beauty" applications but mechanisms may differ.

Widely available globally as dietary supplement. Legal under DSHEA in the United States and equivalent supplement regulations in most jurisdictions. Not on WADA prohibited list. ch-OSA (BioSil) is manufactured by Bio Minerals NV (Belgium) and licensed to multiple supplement manufacturers globally, BioSil branded products from Natural Factors and similar are widely available. Generic horsetail extract supplements are widely available from Solgar, NOW Foods, Nature's Way, Gaia Herbs, and other manufacturers. Quality variation across horsetail products is substantial; reputable manufacturers with species verification (Equisetum arvense, not E. palustre) and processing verification (thiaminase inactivation) provide reliable products. Mineral water sources (Fiji Water, Volvic) provide alternative dietary silicon. Bamboo silica extracts available from select manufacturers. Production of synthetic ch-OSA involves Belgian Bio Minerals NV proprietary chemistry; horsetail production is from cultivated or wild-harvested Equisetum arvense (primarily European and North American sources). Pricing varies substantially, ch-OSA carries premium pricing reflecting clinical inheritance and proprietary chemistry; horsetail products are typically more cost-effective.

Status current as of July 2026. Regulatory positions change, sometimes quickly.

Class

Trace element / botanical (horsetail) hybrid category

Element abundance

Second most abundant in Earth's crust

Element discovery

1824 (Berzelius, Sweden)

Essentiality establishment

1972 (Carlisle UCLA, Schwarz VA in animals)

Standard supplementation dose

5-10mg elemental silicon/day

ch-OSA developer

Bio Minerals NV (Belgium, 1990s)

What follows is unfinished work on our side, not a finding about Silica. A short entry is not a safe entry.

• Cost and market. We have not documented what it sells for or who sells it.
• Supply chain. We have not mapped where it is made.
• Who uses it. We have not documented the user groups.
• What could change. No forward-looking summary yet.
• How it compares. We have not set it against the alternatives.
• Children and teenagers. We have not checked what is known about younger people.
• Where we land. We have not taken a position on this yet.