Comparison

C/Lysine Plus and L-Lysine + Vitamin C

C/Lysine Plus (Douglas Laboratories) lists 2 distinct ingredients and L-Lysine + Vitamin C (Cooper Complete) 2 (rows of one ingredient counted once); 2 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/Lysine Plus	L-Lysine + Vitamin C
Vitamin C	2,000 mg (2222%)	2,000 mg (2222%)
Lysine	1,000 mg	1,000 mg

Amounts are per serving as DSLD gives them: C/Lysine Plus, 4 vegetarian capsules; L-Lysine + Vitamin C, 4 vegetarian capsules. Current labels entered August 2020 and March 2023. Percentages of the Daily Value from 21 CFR 101.9. Source: NIH ODS Dietary Supplement Label Database.

Each product on its own

C/Lysine PlusDouglas Laboratories: every row against all products listing it
L-Lysine + Vitamin CCooper Complete: every row against all products listing it