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Silicon (orthosilicic acid)

Silicon (orthosilicic acid) suppliers and sourcing guide

Orthosilicic acid, Si(OH)4, is the simplest soluble form of silicon. On its own it polymerizes into silica gel as it concentrates, so commercial ingredients hold it in a stabilized form, most often a concentrated liquid with choline chloride (choline-stabilized orthosilicic acid) or the same complex on a powder or beadlet carrier. Brands buy it as liquid for drops and as powder or beadlets for capsules, with silicon content stated.

See suppliersWhat to ask for on the COA
Also known as
Orthosilicic acid · Choline-stabilized orthosilicic acid · ch-OSA · Monosilicic acid
Facts checked
November 2026

Forms and grades of silicon (orthosilicic acid)

Suppliers sell different products under the same name. Specify the one you need.

  • Choline-stabilized liquid

    Orthosilicic acid stabilized with choline chloride as a concentrated solution, often in glycerol, for drops and liquid fills.

  • Beadlets and powders

    The stabilized complex on a carrier such as microcrystalline cellulose for capsules and tablets.

  • Methylsilanetriol

    A related monomeric silicon compound sold as a separate ingredient.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Silicon assay
Total silicon by ICP-OES, reported as silicon rather than silica.
Monomeric silicic acid
A molybdate colorimetric test for monomeric silicic acid, which shows how much has not polymerized.
Choline content
Choline by titration or HPLC for choline-stabilized grades.
pH and density
For liquids, checks that the concentrate matches the specification.
Heavy metals and microbiology
Lead, arsenic, cadmium and mercury by ICP-MS, plus total plate count, yeast and mold.

Storage, lots and expiry

Storage and shelf life

Store stabilized orthosilicic acid in tightly closed containers at moderate temperature as the supplier directs; warmth, dilution and pH changes can make the acid polymerize. Liquids should not be frozen unless the supplier allows it. Shelf life is set by the supplier's stability data, with silicon and monomer content the usual retest checks.

Lots and expiry dates

Record silicon content, and for liquids the density and pH, for each lot. Cloudiness or gel in a liquid points to polymerization, so inspect lots on receipt and before use.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

  • Health Canada's Multi-Vitamin/Mineral Supplements monograph for natural health products lists orthosilicic acid and choline-stabilised orthosilicic acid among the source ingredients for silicon (Table 2).

    Source: webprod.hc-sc.gc.ca (opens in a new tab)

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Silicon (orthosilicic acid) suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking silicon (orthosilicic acid) suppliers now

Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.

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Frequently asked questions

What forms of silicon (orthosilicic acid) can brands buy?

Common forms include choline-stabilized liquid, beadlets and powders and methylsilanetriol. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for silicon (orthosilicic acid) include?

Expect silicon assay, monomeric silicic acid, choline content, pH and density and heavy metals and microbiology, each with its method, specification and result for that lot.

How should silicon (orthosilicic acid) be stored?

Store stabilized orthosilicic acid in tightly closed containers at moderate temperature as the supplier directs; warmth, dilution and pH changes can make the acid polymerize. Liquids should not be frozen unless the supplier allows it. Shelf life is set by the supplier's stability data, with silicon and monomer content the usual retest checks.

What is the regulatory status of silicon (orthosilicic acid)?

Health Canada's Multi-Vitamin/Mineral Supplements monograph for natural health products lists orthosilicic acid and choline-stabilised orthosilicic acid among the source ingredients for silicon (Table 2).

More vitamins and minerals

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