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Supplement Savvy, Part 4: Quality and Purity

This is Part 4 in the Supplement Savvy series by Jeremy Appleton, ND, CNS. Previous articles include:
Part 1: Understanding Food and Supplement Labels
Part 2: Product Potency
Part 3: Finding Authentic Herbal Supplements

People who buy and take dietary supplements are often unaware of the many critical factors that affect product quality and purity. Their purchases are more often dictated by how much the product costs, how it is packaged and advertised, and whether it has been recommended to them. However, even a product with slick packaging, convincing advertisements, or an attractive price point may fail to meet its label’s claims for the content of its active ingredients. Worse (as we have unfortunately learned from numerous incidents over the years with supplements imported from China), there may be adulterants or contaminants present that are not ever tested for.

Issues that affect product quality and purity:

  • Quality and purity of raw materials
  • Accuracy of the Supplement Facts panel
  • Cleanliness of the production environment
  • Quality of the laboratory facilities used to analyze the raw materials and finished goods
  • Adherence to Good Manufacturing Practices (GMPs)

Despite the presence of many high-quality dietary supplements on the market, demand for these products has created opportunity for unscrupulous suppliers of raw materials and finished products to prey on unsophisticated buyers unfamiliar with vendor quality assurance and product quality control practices. Because the U.S. Food and Drug Administration (FDA) has been slow to implement and enforce Good Manufacturing Practices, regulation concerning quality and purity has largely been left to industry itself. As a result, misbranded products and products of substandard quality—including deliberately adulterated and otherwise contaminated products—continue to proliferate on the market. This makes it challenging for consumers to use dietary supplements with confidence, and it makes many doctors wary of their safety and efficacy. Most natural medicines are safe, but there is unfortunately a disturbing variance in quality among finished dosage forms.

Raw material cost alone is too often the dominant factor driving the purchasing decisions of raw ingredients buyers. Buyers naturally look for the lowest priced ingredients that can meet their specifications, which may be none too stringent. In fact, ingredient specifications vary wildly in terms of consistency, and manufacturers are often quite lax about how they certify the identity, purity and potency of their ingredients. When the central question is, “Who can offer the lowest price?” the answer is generally not the company that invests in quality and research.

Competition from China has for years forced prices in the U.S. dietary supplements industry downward. Product “dumping” by Chinese dietary supplement manufacturers is a common practice, used as a means to capture market share by driving the price per kilogram for raw materials to levels that make it difficult for American or European companies to compete. China has taken over a dominant role as the leading supplier of raw ingredients used in dietary supplements sold in the U.S. However, as several recent scandals have made evident, the resulting lower prices may come with a hidden price: the risk of consuming unsafe levels of toxic contaminants.

Environmental toxins (for example: heavy metals, organochlorine pesticide residues, antibiotics, and hormones) have been reported in traditional medicines, patent medicines, raw materials, and foods imported into the United States from China, India, and other countries. A few years back, the U.S. Customs Service and the FDA announced that they discovered bulk imports of Chinese honey that were contaminated with low levels of chloramphenicol, a powerful and potentially harmful antibiotic. The FDA regulates chloramphenicol as a drug, not an approved food additive. The contaminated honey was detected during an investigation into a widespread scheme to evade payment of US antidumping duties on bulk imports of Chinese honey. The honey had allegedly been illegally trans-shipped through other countries on its way from China to America. Chloramphenicol residues also have been found in shrimp exported from China, leading to increased testing of shrimp by the FDA and an outright ban of all Chinese animal product imports by the European Union. Most recently, melamine (an industrial chemical that should not be present in food) has been found in Chinese milk products and candies and has been at the center of a major food scandal that has affected the entire Western world and resulted in numerous product recalls.

Within the supplement industry sector, there are numerous anecdotal reports of imported raw materials failing specifications testing, or testing positive for contaminants. And since typical quality control analyses of raw ingredients are limited to certain markers and do not screen for a broad range of contaminants, most cases of contamination probably go unnoticed. Competing with China’s nearly unbeatable prices puts manufacturers in the difficult position of having to cut expenses wherever they can; and often, it is the non-required, expensive screening of their products that goes out the door first.

U.S. regulatory agencies do not assure the safety or quality of imported ingredients used in dietary supplements. More ominously, we lack controls sufficient to prevent the introduction of contaminated dietary supplements to the U.S. market. It is not financially practical to assess every batch of incoming raw material for a broad spectrum of contaminants. Therefore it is vital that brand manufacturers at least audit the quality control measures of their suppliers.

Do these risks mean that all supplements are unsafe? Certainly not. There are many reputable manufacturers who go the extra distance to make sure their products are top-quality. It takes only a bit of research to identify which companies these are. If the end-user takes away one lesson from all of this, it should be: do not skimp on quality.


  • Bushkin G, Bushkin E. The straight facts about dietary supplements. Health Prod Bus 2002; April.
  • United States Department of Health and Human Services, Food and Drug Administration. FDA increases sampling of imported shrimp and crayfish (crawfish). FDA News Release, June 14, 2002. Available at: Accessed October 19, 2008.
  • United Kingdom Food Standards Agency. Melamine update: Novelty products withdrawn. Accessed October 19, 2008.