Many Americans take dietary supplements. If your skin does not get regular exposure to sunshine, doctors recommend you ingest vitamin D. If you follow a plant-based diet, you probably take vitamin B12. In addition you may have decided to take curcumin or omega 3 capsules for their anti-inflammatory effects or a probiotic to boost your gut’s microbiome.
How sure can you be that these pills you buy are worth the money you spend on them? Unfortunately, not very. Just because you see something on the shelf of the grocery store doesn’t mean it’s beneficial. But with a bit of homework you can significantly improve your odds of finding supplements that work for you.
In this post I’ll look at the regulations governing supplements, the extent to which they fail to protect consumer interests, and ways you can make up for this failure. I’ll answer the following questions:
- What are dietary supplements?
- What does the law say about them?
- Do good manufacturing practices for supplements protect you?
- How does third party certification of dietary supplements work?
- What certification organizations can and can’t be trusted?
- How can you ensure that a supplement boosts your health?
- Is it a good idea to buy proprietary blends?
What are dietary supplements? The Dietary Supplement and Health Education Act
The governing law for dietary supplements is the Federal Food, Drug, and Cosmetic Act as amended by the Dietary Supplement and Health Education Act (DSHEA) of 1994.
DSHEA provides a clear-cut definition of dietary supplements. They are products that are additions to one’s diet and contain at least one of the following ingredients: a vitamin; a mineral; an herb or other botanical; an amino acid; a concentrate, metabolite, constituent, extract, or combination of these previously mentioned ingredients; or another substance that’s part of the human food supply and used to supplement one’s diet.
DSHEA also specifies what information has to be included on the supplement label and what information is optional.
The act has a major weakness: It assumes that supplements are safe for human consumption unless they contain ingredients that were not in the U.S. food supply prior to 1994. Hence it does not require manufacturers to prove the safety of their products. Instead, says attorney Richard Nowak, DSHEA forces the U.S. Food and Drug Administration (FDA) to prove that a particular dietary supplement is unsafe for consumer use before pulling the substance off the market.
In the case of the supplement Hydroxicut this harmed the public. Only after receiving twenty-three reports of serious health problems related to liver damage and learning of the death of a teenager, says Nowak, did the FDA issue a warning to consumers. In 2009, at last, Hydroxicut was pulled from circulation. 
The Food and Drug Administration issues good manufacturing practices
While the 1994 law is unconcerned about the safety of dietary supplements, it does care about consistency in product quality. That’s why it enables the Secretary of Health and Human Services to issue guidelines for manufacturing, testing, and quality assurance.
After a lengthy rule-making process the FDA issued these guidelines in 2007. They are called “Current Good Manufacturing Practices” (cGMPs). The cGMPs establish “industry-wide standards requiring that dietary supplements are manufactured consistently as to their identity, purity, strength, and composition.” They cover the entire manufacturing process, from storing equipment and avoiding backflow from waste piping systems to keeping records that allow each batch of final product to be traced back to the supplier of original ingredients.
As far as consumers are concerned, the cGMPs seek to ensure that the product inside the bottle matches the list of ingredients on the label, that the ingredients are of high quality, and that they are free of contaminants. Take the supplement Cellucor Super HD Xtreme as an example. Its label lists caffeine anhydrous, caffeine pterostilbene cocrystal, and several other ingredients. The cGMPs aim to ensure that the caffeine pterostilbene cocrystal is pure.
The cGMPs do not ensure that a dietary supplement lives up to the health claims printed on its bottle. For instance, Cellucor Super HD Xtreme claims to boost weight loss and to act as a “powerful energy intensifier and mood support.” The cGMPs do not guarantee that these claims are truthful.
That the FDA issued industry guidelines is an important step in the right direction. Unfortunately, the agency does not have the resources to properly enforce them. That’s why we continue to hear of scandals in the supplement industry. In April 2015, for example, New York State Attorney General Eric Schneiderman found out that many supplements either contained ingredients not listed on the labels or failed to contain listed ingredients. This shows that consumers still grapple with how to protect themselves against low-quality ingredients and against harmful supplements like Hydroxicut.
Third party certification offers protection against low-quality ingredients
The solution to the problem of low-quality ingredients is third party certification. Several third party auditors now certify supplement manufacturers for cGMP compliance. Under this business model a supplement producer buys an audit and the right – if the audit is successful – to place the auditor’s seal on its supplement bottles. The idea is that consumers will value dietary supplements carrying a certification more highly than supplements that are not certified.
For consumers this shifts the burden of verification from determining what supplement is good to determining what certification program can be trusted. Below I’ll look at several such certification programs.
A certification that’s not trustworthy: The Natural Products Association
Founded in 1936 “to promote and protect the unique values and shared interests of retailers and suppliers of natural nutritional foods and natural products,” the Natural Products Association is the national association for the supplements industry. It lobbies Congress for lenient standards.
In cooperation with the auditor UL it has developed its own GMP certification program. NPA says its certification includes all cGMP requirements of the FDA plus additional (but unspecified) home-grown standards. The argument is that since NPA’s requirements are more extensive than those of the FDA, its certification is more valuable.
What undermines this claim is the fact that NPA suffers from a conflict of interest that extends to its partner UL. Since NPA is beholden to its due-paying members rather than to the public, it has an incentive to give member companies an easy pass, and consumers may end up paying the price. That’s why I don’t trust this certification. I also don’t trust NOW Foods, whose certification comes from NPA.
Four trustworthy certification programs
Below are four certification programs that I consider trustworthy.
NSF International has been in the standardization business since 1944, when it developed rules for the sanitation of soda fountains. 70 years later it provides certifications from everything from swimming pools to cosmetics, including non-genetically-modified (non-GMO) products.
The not-for-profit moved into the area of dietary supplements in 2001, launching a program that certified products for being free of contaminants and for containing high quality ingredients.
At present the organization provides two types of certification for supplements:
- “NSF Certification to NSF/ANSI 173.” Products certified to this standard must exhibit a match between what’s on the label and what’s in the bottle. They must be free of toxins and contaminants, and they must comply with the FDA’s cGMPs.
- “NSF Certified For Sport.” Supplements certified to this standard must meet the requirements of NSF/ANSI 173. In addition they must be free from substances that are banned in competitive sports.
Once a dietary supplement is certified, it may display the NSF seal. The organization’s website provides a database of NSF/ANSI 173 certified products and a listing of the products that are NSF Certified For Sport.
The U.S. Pharmacopeial Convention (USP)
USP is a scientific nonprofit organization of great prestige. Established in 1820, it describes its work as setting “standards for the identity, strength, quality, and purity of medicines, food ingredients, and dietary supplements.”
This video tells USP’s story:
USP offers the supplement industry a certification that resembles NSF/ANSI 173. That certification indicates:
- That the supplement has been produced in compliance with the FDA’s cGMPs;
- That the ingredients on the label are in the bottle;
- That the supplement contains no harmful contaminants.
Dietary supplements that achieve certification may display the USP Verified Mark. To date four companies – NatureMade, Kirkland, TruNature, and Berkley&Jensen – have completed USP certification. Their certified products can be viewed here. Fourteen additional companies are undergoing verification.
Banned Substances Control Group (BSCG)
Established in 2004, BSCG’s original mission was to bring transparency into the nutritional supplementation of athletes by certifying supplements that were free from banned substances. It has since expanded into the broader consumer market.
Its supplement certification – “BSCG Certified Drug Free® – Supplement Products” – tests for cGMP compliance, the absence of harmful contaminants, and the quality of ingredients on the label. In addition it verifies that the supplement is free of substances banned in competitive sports and of prescription and over-the-counter drugs. Certified supplements may display the BSCG seal.
Supplements currently certified by BSCG can be found here.
ConsumerLab’s business model differs from that of NSF, USP, and BSCG. Instead of offering testing and certification to companies that seek out its services, it tests, for about 140 different supplement categories, a range of nationally available products and then rates them in a way that’s reminiscent of Consumer Reports. Consumers gain access to the ratings by buying a twelve-month subscription for $39 or a twenty-four month subscription for $64. In addition companies whose supplements receive high ratings can purchase the right to display the ConsumerLab seal on the rated supplements.
Here is how ConsumerLab describes its testing procedure:
Products are tested, whenever possible, for each of the following:
- Identity: Does the product meet recognized standards of identity and does the product meet the level of quality claimed on the label?
- Strength (quantity): Does the product contain the amount of ingredient claimed on the label?
- Purity: Is the product free of specified contaminants?
- Disintegration: Does the product break apart properly so that it may be used by the body? [See ConsumerLab.com Home Test for Disintegration for how to test your supplements]
These quality criteria must be met to be considered Approved by CL. If a manufacturer seeks to use the CL Seal of Approval on the product, the product must be tested for these criteria every twelve months based on a random sample purchased on the open market.
Unlike the other certification companies, ConsumerLab does not seem to test for compliance with FDA cGMPs.
The company offers its subscribers access to about 140 product comparisons and to an encyclopedia on herbs and supplements, medical conditions, drug interactions, alternative therapies, functional foods, and homeopathy.
I find this encyclopedia somewhat rudimentary – it provides a great starting point for investigating substances or conditions but not the final answer. The real gem at ConsumerLab is the product rankings – they are far more user-friendly than consumer resources provided by the other certifying organizations.
How can you determine if products advance your health?
If you go with a product certified by NSF, BSCG, or USP, you can be sure that the product is free of contaminants, that its ingredients are of high quality, and that it was manufactured in compliance with the FDA’s Current Good Manufacturing Practices. While ConsumerLab does not test for cGMP compliance, it offers subscribers valuable product ratings that include price comparisons and an overview of what the tested supplements are supposed to accomplish. With these tools you can make informed buying decisions.
Keep in mind that a company’s cGMP compliance does not tell you whether the supplements it sells are actually good for you. It does not clarify, for example, whether or not chondroitin will heal your osteoarthritis. For that you have to do your own research. ConsumerLab’s encyclopedia provides a good launching pad. Other resources are your doctor’s advice or websites like The People’s Pharmacy.
The previous statement applies to dietary supplements where every single ingredient and its quantity is listed. Proprietary blends are a different story. A proprietary blend is a bundle of ingredients where the respective ingredient quantities are kept secret – the consumer has an idea of the substances in the mix but not their specific amounts. The FDA permits proprietary blends provided that they are identified as such. On the supplement facts label the components in the blend must be listed in descending order of predominance by weight.
Let’s go back to our earlier example, Cellucor Super HD Xtreme. The label lists “SuperHD Xtreme™ Blend” as a proprietary blend. When you read the supplement facts label you see that the blend consists of caffeine anhydrous, tetramethyluric acid, cayenne fruit extract, caffeine pterostilbene cocrystal, sceletium tortuosum aerial parts extract, and rauwolfia vomitoria root bark extract. But you can’t tell how much of each substance is in the supplement.
ConsumerLab warns against these concoctions:
“ConsumerLab.com has long cautioned against purchasing supplements with proprietary formulas and typically does not test them. We may, however, check listed amounts of other key, individually listed ingredients in the same supplement. In some cases, we have found high levels of contaminants which, we suspect, originated from ingredients in a proprietary formula.
The major problem with “proprietary formulas,” as well as with proprietary “blends” and “complexes,” is that they permit manufacturers to withhold important information about what’s really in a product.
Proprietary formulas are often developed around an expensive ingredient, like CoQ10, because this allows a company to use less of the expensive ingredient, creating a formula in which the expensive ingredient is just a small part of the formula. We have seen this with ingredients such as chondroitin in joint supplements, and SAMe. We also see proprietary formulas marketed for uses such as cognitive enhancement, nerve pain, or weight loss where a company may try to impress the consumer with a laundry list of ingredients having only shreds of evidence relating to the intended use. In most cases, the formulas themselves have not been clinically tested.”
My advice is therefore to stay away from proprietary blends. For all other supplements I recommend the following steps:
- Do your research to determine whether the substance in fact advances your health.
- Once you have determined that the substance is beneficial for you, select a product that is certified by a trustworthy organization or has received a positive rating from ConsumerLab.
Keep in mind that dietary supplements can help you bridge deficiencies, but they cannot make up for a poor lifestyle. That’s why you should be just as vigilant about the foods you put in your mouth as about the pills, tablets, and tonics you ingest.
Update January 21, 2016: A day after this blog post appeared, PBS Frontline aired the documentary “Supplements and Safety.” It examines the problems in the dietary supplement industry but does not mention the possibilities of third party certification. It’s a very interesting show, which you can watch online here.
Notes and works cited
 DSHEA requires supplement manufacturers to list those nutrients on their labels for which the Secretary of Health and Human Services issued a recommendation for daily consumption (such as total fat, saturated fat, cholesterol, or sodium)), provided that those nutrients appear in significant amounts. Ingredients for which the Secretary issued no recommendations must also be listed, either one by one or as a proprietary blend. You can find this information at U.S.C. 21 U.S.C. 343(q)(5)(F), here.
Moreover, DSHEA allows the manufacturer of a supplement to make a number of health claims provided that the manufacturer has some sort of “substantiation” that these health claims are truthful and that the phrase “This statement has not been evaluated by the Food and Drug Administration” be included on the label. Permissible health claims are:
- that the supplement provides benefits in relation to a classical nutrient deficiency disease;
- that it affects the structure or function in humans,
- how the supplement acts to maintain such structure or function, or
- that the supplement engenders general well-being.
 Supplements containing new dietary ingredients that have not, prior to October 1994, been present in the U.S. food supply, are considered adulterated.
 Nowak, Richard E. “DSHEA’s Failure: Why a Proactive Approach to Dietary Supplement Regulation Is Needed to Effectively Protect Consumers.” University of Illinois Law Review 2010 (2010): 1045-1081. Article is available online here.
 For an overview of the rule, see: U.S. Food and Drug Administration. 2007. Overview of the Implementation of the Current Good Manufacturing Practices for Dietary Supplements Guidance for Industry: A Prepared Script for a Satellite Broadcast. Available online here.
 U.S. Food and Drug Administration. 2007. Overview of the Implementation of the Current Good Manufacturing Practices for Dietary Supplements Guidance for Industry: A Prepared Script for a Satellite Broadcast. Online here.
 The only selection you must make on that page to get a list of results is for “product type.”
 For example, the encyclopedia entry on turmeric does not discuss the possibility that black pepper enhances turmeric’s anti-inflammatory effects by increasing its blood levels.