Silicea D6 Schussler Salt No. 11. Silica helps maintain the elasticity and strength of hair and nails. It is useful, for example, in cases of brittle hair and nails, hair loss, or uneven nail growth. Posology: Allow the tablets to dissolve slowly in the mouth, away from food, approximately 30 minutes before or after. The usual dose is 2-4 tablets daily, unless otherwise indicated by a physician.