Comparison

C-500 and Vitamin C Crystals

C-500 (Optimox) lists 1 distinct ingredients and Vitamin C Crystals (Country Life) 1 (rows of one ingredient counted once); 1 are on both labels. On the site's similarity measure, which compares ingredient lists (1 for the same list, rarer ingredients counting for more; amounts are not part of it), the two formulas score 1.00: the same ingredients, at the amounts in the table below.

Amount per serving (and % of the Daily Value)
Ingredient	C-500	Vitamin C Crystals
Vitamin C	3,000 mg (3333%)	2,500 mg (2778%)

Amounts are per serving as DSLD gives them: C-500, 6 tablets; Vitamin C Crystals, 2.5 g. Current labels entered April 2014 and July 2025. Percentages of the Daily Value from 21 CFR 101.9. Source: NIH ODS Dietary Supplement Label Database.

Each product on its own

C-500Optimox: every row against all products listing it
Vitamin C CrystalsCountry Life: every row against all products listing it