Silicon

non-nutrient/non-botanicalsilicon atom

What is it

Silicon is the second most abundant element on Earth and is present in small amounts in foods, especially whole grains, beer, and certain vegetables. Although not formally classified as essential for humans, growing evidence supports a beneficial role in connective tissue, bone, hair, and skin.

How it works

In food and water, silicon exists primarily as orthosilicic acid (OSA), the form most bioavailable to humans. OSA is absorbed in the small intestine and reaches connective tissues, where it appears to influence collagen synthesis, cross-linking of glycosaminoglycans, and mineralization of bone matrix. Research suggests silicon helps activate prolyl hydroxylase, an enzyme essential for collagen formation. It also appears to support the structural integrity of skin, hair, nails, and arterial walls. Unlike most trace elements, silicon has wide tissue distribution and is found in highest amounts in connective tissues, including aorta, trachea, tendons, bones, and skin.

Evidence for 4 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Bone health

Grade C

Moderate evidence

Observational studies link higher silicon intake with greater bone mineral density at the hip in pre- and postmenopausal women. A few small trials of choline-stabilized OSA suggest improvements in markers of bone formation when combined with calcium and vitamin D.

Hair, skin, and nails

Grade C

Moderate evidence

Small trials of ch-OSA (10 mg/day) over several months have shown modest improvements in hair tensile strength, skin elasticity, and nail brittleness. Effects are modest and the evidence base is limited.

Collagen synthesis support

Grade C

Moderate evidence

Mechanistic evidence suggests silicon supports prolyl hydroxylase activity in collagen formation. Whether dietary supplementation meaningfully accelerates collagen production in humans is unclear.

Cardiovascular health (arterial wall integrity)

Grade D

Mixed evidence

Animal studies suggest silicon contributes to elastin and arterial wall integrity. Human evidence linking supplementation to cardiovascular outcomes is sparse.

4 commercial forms

Choline-stabilized orthosilicic acid (ch-OSA)

Most bioavailable form; mimics naturally occurring OSA in beverages.

The form used in most clinical trials, particularly for hair, skin, nails, and bone. Brand examples include BioSil.

Orthosilicic acid (OSA, often in liquid)

High bioavailability when stabilized.

Found in some liquid supplements and naturally in beer and mineral waters.

Horsetail (Equisetum arvense) extract

Moderate bioavailability; contains other plant compounds.

Traditional botanical source of silica. Long-term use may deplete thiamine and has mild diuretic effects.

Silicon dioxide / colloidal silica

Poor bioavailability in solid form.

Used primarily as a tablet excipient (anti-caking agent), not as a meaningful source of bioavailable silicon.

Dosage

There is no RDA or AI for silicon. Estimated typical intake ranges from 20-50 mg/day from food. Supplements (often as orthosilicic acid, choline-stabilized OSA, or horsetail extract) typically provide 5-20 mg/day. No UL has been established. Silicon from food is considered safe at any practical intake; supplements are usually well-tolerated at recommended doses.

When and how to take it

Silicon supplements are typically taken with food and water. There is no preferred time of day. Orthosilicic acid is often dosed once daily; horsetail extracts may be taken 1-3 times per day. Drink plenty of water if using horsetail to minimize any urinary effects.

Food sources

Food	Amount	%DV
Beer (12 oz)	Up to 14 mg	—
Whole grain bread (1 slice)	3-5 mg	—
Brown rice (1 cup, cooked)	5 mg	—
Oats (1 cup, cooked)	8 mg	—
Bananas (1 medium)	5 mg	—
Green beans (1/2 cup, cooked)	3 mg	—
Bottled mineral water (1 cup)	Varies widely (0-40 mg/L)	—

Safety

Silicon from food and beverages is very safe. Orthosilicic acid and choline-stabilized OSA supplements are well-tolerated at typical doses. Silica from horsetail (Equisetum) can contain thiaminase, an enzyme that breaks down vitamin B1, so high-dose or long-term horsetail use without thiamine support is discouraged. Industrial silica dust inhalation causes silicosis but is unrelated to dietary intake.

Who should be cautious

Pregnant women and people on diuretics should be cautious with horsetail-based silicon, which has diuretic and thiamine-depleting properties. People with kidney disease should consult a clinician. Avoid prolonged use of horsetail without thiamine supplementation. Bioavailable forms like ch-OSA are generally well-tolerated.

Interactions

Few significant drug interactions documented. Horsetail-based silicon supplements may have mild diuretic effects and interact with certain heart and blood pressure medications. Long-term high-dose horsetail can lower thiamine status. Some antacids contain silicon compounds; not a concern at therapeutic doses.

Frequently asked questions

Is silicon the same as silica or silicone?⌄

Silicon is the element. Silica (silicon dioxide) is silicon combined with oxygen. Silicone is a synthetic polymer with silicon in its backbone, used in medical implants and household products. Only orthosilicic acid (a form of silica in water) is well-absorbed by humans.

Will silicon really make my hair and nails stronger?⌄

Small studies of choline-stabilized OSA show modest improvements over several months. The effect is not dramatic, and individual responses vary. Better hair and nail outcomes generally require addressing diet, thyroid status, and iron levels alongside silicon.

What's the best form of silicon?⌄

Choline-stabilized orthosilicic acid (ch-OSA) has the most clinical trial support and highest bioavailability. Liquid OSA is similar. Horsetail provides silicon but with additional plant compounds and concerns at high doses.

Is beer really a good source of silicon?⌄

Yes, surprisingly. Beer contains highly bioavailable silicon from the malted barley and hops. A 12-oz beer can provide 10-14 mg, though this is not a recommendation to drink beer for health.

Is silicon safe long-term?⌄

Orthosilicic acid forms appear safe at typical supplement doses. Long-term high-dose horsetail can deplete thiamine and is best avoided or combined with a B-complex.

References

Silicon and bone health — Linus Pauling Institute link

Track Silicon with Pilora

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.