Comparison

Mega NAC + Quercetin and Ultimate Respiratory Defense

Mega NAC + Quercetin (Body Kitchen) lists 3 distinct ingredients and Ultimate Respiratory Defense (Swanson) 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 0.70.

Amount per serving (and % of the Daily Value)
Ingredient	Mega NAC + Quercetin	Ultimate Respiratory Defense
Quercetin	600 mg	300 mg
N-Acetyl Cysteine	600 mg	600 mg
Black Pepper	10 mg

Amounts are per serving as DSLD gives them: Mega NAC + Quercetin, 2 vegetable capsules; Ultimate Respiratory Defense, 1 veggie capsule. Current labels entered November 2022 and February 2025. Percentages of the Daily Value from 21 CFR 101.9. Source: NIH ODS Dietary Supplement Label Database.

Each product on its own

Mega NAC + QuercetinBody Kitchen: every row against all products listing it
Ultimate Respiratory DefenseSwanson: every row against all products listing it