Silica supplements can promote hair growth and strength, but should be used with caution.
Silica supplements, usually from the plant horsetail (Equisetum) can increase the thickness of hair and help it maintain its strength and elasticity. Plant-based forms of silica have varied absorption rates. Choline-stabilised orthosilicic acid has been tested and demonstrated to be effective, but is more expensive.
Silica supplements should be used with caution: horsetail herb can cause liver damage and vitamin B1 deficiency if overused.