Clear evidence. Transparent sources. Practical guidance. Our evidence policyContact
Food Health Lab
Home › Supplements › Silicon

Silicon — The Complete Supplement Guide

Marketed for hair, skin, nails and bone — what the connective-tissue mineral silicon actually does, which form is absorbed, and how strong the evidence really is.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsMineralsSilicon

Silicon is an ultratrace element linked to bone and connective-tissue health. It is not classed as essential, and the form matters a lot for whether it is absorbed. For the short dietary version, see the Minerals page.

Read first. Silicon is not established as an essential nutrient and most diets provide it. Supplements are generally safe but the evidence for benefit is preliminary; choose an absorbable form. Information, not a prescription.

Key takeaways

  • Not classed as essential; linked to bone and connective-tissue health.
  • No official requirement; diet ~20–50 mg/day (studied ~10 mg as ch-OSA).
  • No upper limit set — low toxicity; the absorbable form (OSA/ch-OSA) matters.

Function

Silicon appears to support the "scaffolding" tissues:

  • Bone & collagen: involved in the early formation of bone and in cross-linking collagen, the protein framework of connective tissue.
  • Connective tissue: may support the strength and elasticity of skin, tendons and blood-vessel walls.
  • Hair, skin & nails: popularly taken for these, based on its connective-tissue role.
  • Not classed essential: a clear human requirement has not been established, so consider these roles supportive rather than proven.

Different forms — and which to choose

Orthosilicic acid (OSA)The bioavailable form — especially choline-stabilised OSA (ch-OSA), used in most positive trials.
Silica (from horsetail/bamboo)Polymerised silica is poorly absorbed unless broken down.
Colloidal / foodWhole-grain and plant foods supply silicon; mineral water can contribute.

Absorption in the body

How muchDepends entirely on form: orthosilicic acid is well absorbed, polymerised silica poorly. Absorbed silicon is excreted in urine.

Deficiency symptoms

SymptomsNo recognised human deficiency, as silicon is not established as essential; animal studies show bone/connective-tissue effects.
NoteIntakes fall with age, which has prompted interest in supplementation for bone.

Recommended intake

No official requirement · diet ~20–50 mg/day

No reference intake is set. Typical diets provide roughly 20–50 mg/day.

Best sources: wholegrains and oats, bananas, green beans, and some mineral waters.1

Therapeutic use

BoneSmall trials of ch-OSA suggest a favourable effect on bone-formation markers and bone density (with calcium/vitamin D) — preliminary.1
Hair, skin, nailsSome ch-OSA trials report improved hair and nail quality and skin elasticity — early evidence, modest.

Therapeutic doses

Studied: ~10 mg/day (ch-OSA)
If triedTrials typically use around 10 mg/day of ch-OSA; choose an orthosilicic-acid form for absorption.
No need to megadoseHigher doses add no proven benefit.

Toxicity & upper limit

No UL set — low toxicity
Upper limitNo UL has been set (EFSA judged data insufficient); dietary and supplemental silicon are considered of low toxicity in people with normal kidneys.
CautionAs with any poorly-defined supplement, avoid excess; those with kidney disease should be cautious.

Bottom line: silicon supports bone and connective tissue and is plentiful in wholegrains, oats and some waters. If you supplement for hair/skin/nails or bone, choose an orthosilicic-acid (ch-OSA) form at a low dose — but treat the benefits as promising rather than proven.

← All supplementsShort dietary version

References

Reference and upper-limit values are general adult figures from official bodies; individual needs vary. Therapeutic doses describe clinical/research use, not prescriptions.

  1. Jugdaohsingh R. Silicon and bone health. Journal of Nutrition, Health & Aging 2007;11(2):99–110 (review of silicon, orthosilicic acid and connective tissue). ncbi.nlm.nih.gov (PMC)

This article summarizes nutrition science from official health authorities and peer-reviewed sources for education. It is not a substitute for individual medical advice, and the doses given are not prescriptions — always consult a professional before therapeutic supplement use, in pregnancy, in kidney disease, or alongside medication.

✓
Bodil Isaksson, Licensed Biomedical Scientist (Sweden)

At Food Health Lab we explain what the science says in plain language, and we cite our sources so you can check for yourself.

Read next

Mineral
Calcium
Mineral
Magnesium
Mineral
Potassium