NSF cGMP stands for National Science Foundation certified Good Manufacturing Processes. This ensures for our customers that what's inside the bottle matches what's on the Supplement Facts label. What you see is what you get.
USP stands for United States Pharmacopeia. The USP insignia indicates that certain vitamin and mineral ingredients in the product have 1) an FDA-approved or USP-accepted use, 2) have been used extensively without a significant safety risk, and 3) meet the quality standards published in the United States Pharmacopeia. These standards specify allowable rates of disintegration and dissolution, strength (range of dosage variance), range of acceptable impurities, and existence of an expiration date.