Identifying Safe and Effective Supplements

Online resources that provide reliable, up-to-date information

Posted Mar 23, 2020

Identifying Safe and Effective Supplements

Finding reliable, up-to-date information on the effectiveness of supplements for enhancing well-being or treating a particular medical or mental health problem is a challenging task for health care providers, patients, and the public at large. The internet contains an enormous amount of information on supplements; however, it is often difficult to find reliable, well-vetted sources of information on their safety and effectiveness.

In this context of information overload, a few web-based resources have emerged as excellent sources of reliable information. In this post, I describe:

  • Expert resources for obtaining accurate, up-to-date information on supplements
  • Standards for the manufacture of natural supplements
  • Services offered by third-party certifiers to ensure compliance with standards
  • Programs aimed at monitoring and preventing adulterants

Supplements Include Micro-Nutrients, Macro-Nutrients, and Combinations

As defined by the Dietary Supplement Health and Education Act of 1994, a dietary supplement is any product, other than tobacco, used to "supplement" the diet, which is not considered a food. Dietary supplements include botanicals, micro-nutrients (i.e., vitamins and minerals), and macro-nutrients (i.e., fats, proteins, and carbohydrates), as well as extracts, metabolites, and combinations of micro- and macro-nutrients (e.g., probiotics and custom-designed micro-nutrient supplement formulas). Roughly one-half of adults and one-third of children in the U.S. and other industrialized countries use dietary supplements that contain a variety of essential and non-essential nutrients.

Standards for Dietary Supplements

The National Center for Complementary and Integrative Health provides practical information for clinicians and consumers on the use trends of many supplements and federal regulations of dietary supplements. The website includes valuable links to the databases of the scientific and medical literature and federal agencies, including the Office of Dietary Supplements (ODS) of the National Institutes of Health (NIH), the Dietary Supplement Label Database (also under the NIH), which is a database of all information found on labels of brands of supplements marketed in the U.S. so that consumers can compare active ingredients listed on product labels with government-recommended amounts.

The NCCIH site includes a link to the Center for Food Safety and Applied Nutrition (CFSAN), which provides services under the auspices of the FDA. Among other responsibilities, CFSAN is tasked with ensuring that foods, natural supplements, and cosmetics are properly labeled. The CFSAN website includes a section called "Tips for Dietary Supplement Users: Making Informed Decisions and Evaluating Information," which includes tips for consumers for being informed users of supplements and tips for searching for reliable information on supplements the web and evaluating research findings.  

National Science Foundation and U.S. Pharmacopeia 

For decades, government agencies, such as the National Science Foundation (NSF) and the U.S. Pharmacopeia (USP), have worked together with private corporations such as ConsumerLab to develop standards for safe extracts derived from botanicals, mushrooms, and other natural products, as well as standards for testing claims of biological activity in natural products. In the U.S., standards are developed by the NSF Joint Committee for Dietary Supplements, which consists of individuals representing the dietary supplement industry, regulatory agencies, and consumer interest groups. An important outcome of efforts to establish standards was the creation of the American National Standard for Dietary Supplements, which establishes criteria for verifying the number of active ingredients and determining safe limits on contaminants, including heavy metals, pesticides, and microbials.

Despite these efforts, there is still no industry-wide consensus on the best methods for evaluating the quality and biological activity of dietary supplements. This has resulted in large differences in estimates of the bioactive constituents of particular supplements, and wide variances in estimates of the bioavailability of particular constituents. 

Natural Medicines is a subscription database that grew out of two databases: Natural Standard and Natural Medicines Comprehensive Database. The site contains over 1,200 peer-reviewed monographs on supplements that include information on safety, effectiveness, and interactions. In addition to professional monographs for health care professionals, the site includes brief reviews abstracted from the monographs and Bottom Line Modality Monographs that include essential information on safety and effectiveness. The site also includes patient handouts, an interaction checker, and an effectiveness checker.

Third-Party Certification

Organizations that are not affiliated with the natural supplement industry provide tests to consumers, industry, and regulatory agencies to ensure compliance with standards. The endorsement of any natural supplement by one or more third-party certifiers is widely regarded as an important step in ensuring product safety and efficacy. Below are brief reviews of the resources and services provided by third-party certifiers.

ConsumerLab offers both voluntary (manufactures choose products) and non-voluntary (CL chooses products) testing of natural supplements. To protect against bias, all products tested are purchased through open retail channels or multi-level marketing companies and not from the supplement manufacturers themselves. Those products that meet CL test standards—which generally reflect agreed-on industry standards—are included in a list of CL-approved supplements available to consumers on a subscription fee basis. In order to remain on the approved product list, a supplement must be re-tested and found to meet standards every 18 months. In addition to providing test results of specific products, CL provides testing of the raw materials used to manufacture supplements, detailed technical reports, and surveys of consumer ratings of different brands.

Natural Products Association is a trade association that represents retailers, health food stores, and manufacturers. Its TruLabel program evaluates products to determine the accuracy of the claims of raw ingredients on product labels. TruLabel test results are available at no cost. 

NNFA also evaluates the manufacturing process used in member companies to determine whether they are in compliance with GMP. NNFA member companies are required to register their product labels in a confidential database and participate in random independent laboratory testing of their products. In cases where the testing results do not match the ingredients listed on the product label, the company is given an opportunity to correct the product or modify the label. NNFA uses third-party auditors (some of whom are former FDA employees) who have no business ties to NNFA to ensure the objectivity of its testing program and test results. 

The National Science Foundation (NSF) is a non-profit organization that runs the Center for Public Health Education, which provides third-party certification services for consumers, industry, and regulatory agencies. Its Dietary Supplements Certification program evaluates supplements to determine whether the contents match the product descriptions on the labels; all ingredients are disclosed; unacceptable levels of adulterants and contaminants are not present; and products are in compliance with GMP standards. Natural supplements and other products that have been certified by the NSF can be found here.

The United States Pharmacopeia offers the Dietary Supplement Verification Program. The USP seal on a product label is a guarantee that the product contains the ingredients on the label in the amounts claimed, is readily absorbed (i.e., has high bioavailability), does not contain harmful contaminants, and has been manufactured following GMP. Hundreds of natural supplements, mainly vitamins and minerals, have been verified by the USP. The USP also offers at no cost hundreds of authoritative monographs on natural supplements. The website contains information for consumers and health professionals at no cost. 

Monitoring and Preventing Adulterants in Natural Supplements

The accidental adulteration of supplements can result from poor quality control during manufacturing and the deliberate adulteration of supplements to save on production costs and increase profits. Natural supplement adulteration results in the uneven quality of different brands, inconsistent health and mental health benefits, and potentially serious safety issues.

In response to widely shared concerns over product adulteration, an industry-funded program was established by the American Botanical Council (ABC), the American Herbal Pharmacopoeia (AHP), and the National Center for Natural Products Research at the University of Mississippi. Reports on adulterants are obtained from researchers, independent analytical laboratories, government agencies, trade associations, and private companies. The goals of the botanical adulterants program include investigating cases of suspected adulteration, providing guidance on the relative strengths and weaknesses of different analytical methods, and educating members of the herbal and dietary supplement industry about ingredient and product adulteration. 

Bottom Line

Finding reliable, up-to-date information on natural supplements poses complex challenges. Once pertinent research evidence has been reviewed, and an appropriate supplement has been identified (e.g., for improving wellness or treating a particular medical or mental health problem), the challenge becomes finding a quality brand that is affordable.

In this post, I have discussed the importance of standards for natural supplements, described services provided by third-party certifiers to ensure compliance with standards, and described the work of independent organizations that provide expert reviews for both clinicians and consumers. I have also commented on the problem of adulteration in supplements and described the work of a program established to investigate cases of suspected adulteration and to educate members of the herbal and dietary supplement industry about adulteration.