What does the USP Seal Mean on a Supplement Label?
Supplements have all sorts of seals, labels, and guarantees on their packaging. But what do they mean? Many are just for marketing purposes and don’t mean anything. But a few are actual certifications that can tell you something about what you’re buying. One of those is the USP seal.
The USP seal is a certification by the U.S. Pharmacopeial Convention. The seal indicates that the supplements in the bottle have been tested for potency, concentration, contaminants, and safe manufacturing practices.
But who is the USP? And what does their seal tell you about the nutritional value of a supplement? Read the following article before you make your next vitamin run, and know what’s inside your vitamins. 
What is the U.S. Pharmacopeial Convention?
The U.S. Pharmacopeial Convention (USP) is a non-profit organization that tests nutritional supplements. The USP is a third-party lab and is not associated with the FDA or any government entity.
Vitamin brands pay the USP to verify that their supplements contain the ingredients on the label in the advertised amounts. Basically, the USP provides a third-party seal of approval stating that the vitamin brand is telling you the truth.
Why Do Brands Buy USP Seals?
Many brands want a USP seal because it establishes credibility and tells customers that their products are safe and effective. Also, some stores won’t sell supplements if they aren’t certified by a third-party lab.
Not all supplement brands have the USP seal, because getting certified is not a legal requirement. The FDA already requires all supplement brands to abide by Good Manufacturing Practices (GMP), which guarantees safety in manufacturing and consistent quality.
What You Need to Know about the USP
Before you shop for just any USP-certified supplements, you need to know this: The USP verifies what’s in the container, but it doesn’t confirm that the ingredients are effective.
For example:
Imagine you’re considering four different magnesium supplements. They all contain 100% of your daily magnesium intake. Each is made with a different form of magnesium. One is made with magnesium glycinate, the second with magnesium citrate, the third with magnesium oxide, and the last with magnesium aspartate.
The first two supplements contain potent magnesium that is easier for your body to absorb (yay!). The third (oxide) is not easy for the body to absorb, meaning it would not be very effective (boo) [1]. And the fourth, magnesium aspartate, can create dangerous neurotoxins that could cause harm (oh no) [2].
Yet, ALL of these products could receive the USP seal of approval as long as they contain exactly what they say on the label and in the correct quantities.
Here’s another example:
The USP would approve a vitamin supplement with 1000% of your daily intake of vitamin C, such as Manna Liposomal Vitamin C, just as easily as it would approve a supplement with 25% of your vitamin C intake. Both would be honest assessments of the contents of the containers. But the first supplement is clearly more potent.
So, while the USP does verify the contents of a bottle of supplements, it does not indicate that a supplement is better or worse than any other.
Is it Worth Buying Supplements with a USP Seal?
Yes, it’s worth buying supplements with a USP seal… if you’ve confirmed that the ingredients are effective. If they are, you have a bonus verification by the USP that your vitamins are made safely and honestly.
To find out if your supplements are effective, you can check the following:
- The form of the nutrient: You’ll find this in parentheses after the name of the nutrient on the vitamin label. Find out how to read a supplement label to learn more.
- The concentration of the nutrient: Check the supplemental facts on the label to see how much of the recommended daily intake is in each serving. This is reflected in a percentage under “Daily Value (DV).”
- The delivery method: How does the nutrition reach your cells? Most nutrition in supplements is lost in your GI tract before it ever reaches your bloodstream. Supplements like Manna’s are bound to liposomes that protect nutrients as they travel through your body, ensuring you absorb more of the good stuff with every dose.
Third-party certifications like the USP seal can help you understand more about supplements just by looking at the package. But there’s a lot they can’t tell you too. The best way to find out which supplements are right for you is to talk to a nutritionist or your doctor. Or, you can learn more about supplements yourself using these nutritionist-reviewed resources.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5652077/
- https://pubmed.ncbi.nlm.nih.gov/7290308/
