Silica (Orthosilicic Acid / Horsetail)

Hair, nails & skin

Function & benefits

Silicon takes part in building collagen and connective tissue in the skin, hair, nails and bones; a clinical trial suggests that choline-stabilised orthosilicic acid (ch-OSA) supports the strength and thickness of fine hair in women.

Dosage & how to use

Recommended dose	10 mg of elemental silicon (ch-OSA), or 300–500 mg of standardised horsetail extract
Best time to take	With lunch and plenty of water
Frequency	Once daily

Best forms to choose

Choline-stabilised orthosilicic acid (ch-OSA), the best-absorbed form, or standardised horsetail extract free of thiaminase.

Important warnings

Horsetail extract must be thiaminase-free, as thiaminase depletes vitamin B1

Avoid horsetail with kidney or heart disease, as it is a diuretic

Avoid during pregnancy and breastfeeding

Drug interactions

Horsetail may strengthen diuretics and lower potassium; use it with care alongside lithium and digoxin.

View in the supplements guide

Related supplements

Scientific references

Wickett RR et al. Arch Dermatol Res 2007 — PMID: 17960402
Araújo LA et al. An Bras Dermatol 2016 (review) — PMID: 27438201

📚 Published sources and research: European Food Safety Authority (EFSA) • National Institutes of Health (NIH - ODS) • PubMed / Cochrane databases

Content last updated: 17 October 2026 · Based on published sources and research (EFSA / NIH / PubMed)

⚖️ Medical disclaimer: The information and data provided here are for health education and nutritional guidance only. They are not a medical diagnosis and never replace a direct consultation with your doctor or pharmacist. Always consult your doctor before starting any supplement, especially during pregnancy or breastfeeding or when taking long-term medication.