Comparison

B-Complex 125 with C and Stress-Plex-Forte

B-Complex 125 with C (GNC) lists 12 distinct ingredients and Stress-Plex-Forte (Douglas Laboratories) 12 (rows of one ingredient counted once); 12 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)
IngredientB-Complex 125 with CStress-Plex-Forte
Vitamin C125 mg (139%)200 mg (222%)
Vitamin B6125 mg (7353%)55 mg (3235%)
Vitamin B12125 mcg (5208%)100 mcg (4167%)
Niacin125 mg (781%)200 mg (1250%)
Folate400 mcg400 mcg
Pantothenic Acid (Vitamin B5)125 mg (2500%)55 mg (1100%)
Riboflavin125 mg (9615%)55 mg (4231%)
Thiamin125 mg (10417%)55 mg (4583%)
Biotin125 mcg (417%)200 mcg (667%)
Choline125 mg (23%)26 mg (5%)
Inositol0.125 mg55 mg
PABA75 mg55 mg

Amounts are per serving as DSLD gives them: B-Complex 125 with C, 1 caplet; Stress-Plex-Forte, 1 tablet. Current labels entered November 2013 and June 2012. Percentages of the Daily Value from 21 CFR 101.9. Source: NIH ODS Dietary Supplement Label Database.

Each product on its own