What works, what does not, and what is dangerous. Reviewed by the Scan Dose Research Team.
Zinc lozenges: shorten colds 2-3 days (within 24hrs, dissolve slowly). NAC 600mg 2x/day during flu season: 68% symptom reduction. Vitamin D: helps ONLY if deficient. Vitamin C: does NOT prevent colds (only helps extreme physical stress). Elderberry: independent study showed it EXTENDED symptoms. Colloidal silver: doesn't work + permanent skin discoloration.