Different countries have different regulations governing the production and manufacture of herbal supplements and it is the job of national regulatory agencies to ensure that these regulations are followed (see Purchasing for links to these regulations). The more reputable companies have rigorous quality control and testing procedures in place to ensure that what they claim to be in their products is actually there. The video follows the testing process in several companies from raw material through to finished product to see inside what some of these companies do. See Quality and Sustainability for a discussion of the broader context of quality control.
Botanical preparations include a complex matrix of hundreds or thousands of different chemical constituents acting in ways that are sometimes known, but quite often are not yet understood, to create particular effects. Contrary to conventional drugs, the so-called “active constituents” in herbal ingredients generally consist of many molecules. And for many plants, it is still a matter of debate which compounds exactly are responsible for the beneficial properties. Good quality control depends on having the expertise and tools required to establish the identity and quality of both the raw ingredients that go into these preparations and the finished preparations. In the US and in many parts of the Western world, pharmacognosy, the scientific discipline that provides the basis of identification, quality, purity and testing of drugs developed from natural products and complex botanical materials, faded from fashion in the early 1960s.
Another challenge in identification is that botanicals are most often purchased in processed form, such as a powdered herb, or a dry extract. Depending on the processing, the morphological characteristics and the specific aroma and taste may be lost, and the analyst has to determine the quality based on the plant’s chemicals. And so many of the current challenges in quality control in the industry as a whole are not necessarily because people don’t want to do the right thing. They are because people lack the knowledge in identity and quality control knowledge, or the resources needed to do it.
The American Herbal Products Association (AHPA), the American Botanical Council (ABC), and the American Herbal Pharmacopeia (AHP) are some of the organizations working to preserve this knowledge and pass it on. Their websites provide a wealth of resources.
ABC, AHP, and the University of Mississippi’s National Center for Natural Products Research (NCNPR)—have initiated the Botanical Adulterants Program, a large-scale program to educate members of the herbal and dietary supplement industry about ingredient and product adulteration. Also see Steven Dentali’s 2010 article Successful Botanical Research Requires Botanical Expertise, for a discussion of how these skills are essential for doing the kind of botanical research necessary to understand whether and how different preparations work.
Link to discussions of regulations in the EEU.
Herbs, like most commodities in trade, can be categorized into a range of defined grades and qualities. Higher grade herbs are more expensive and have more rigorous standards that must be met. Lower grade herbs are less expensive, have lower quality control standards, and are lower quality. As Josef Brinckmann writes,
In the United States there are markets for all qualities. The highest grades of botanicals are available for quality-oriented buyers who need their herbal products to demonstrate reproducible efficacy and safety for specific intended health benefits. The lowest grades of botanicals are available for price-oriented buyers who need their herbal products to satisfy considerable consumer demand for low prices and discounts and/or shareholder demand for higher profits (“Reproducible Efficacy and Safety Depend on Reproducible Quality,” Herbalgram 2011: 41 – see Brinckmann’s article for an excellent discussion of the different standards and their impact on specific characteristics of several plants.)
As Brinckmann continues, it isn’t so black and white. The quality needed depends on the end use, whether the botanicals will be used in food grade tea or as a botanical drug used for therapeutic purposes. Botanical products that are legally approved as botanical drugs must meet pharmacopoeial quality standards as outlined in the official pharmacopeias (books with individual monographs setting forth standards of identity, strength, quality, and purity). For approved botanical drugs, the only officially recognized pharmacopoeia in the US is the United States Pharmacopeia. Manufacturers can manufacture herbs in compliance with other quality standards such as those produced by the American Herbal Pharmacopoeia, European Pharmacopoeia, other pharmacopoeias or USP’s own Herbal Medicines Compendium. Additionally, manufacturers do not have to follow any pharmacopoeial standards at all. Instead, they can develop their own internal standard, as long as they have a scientific rationale for that standard.
Samples of different grades of herbs at Agrimed, Germany.
A small number of herbal materials that approved as drugs, and are required to meet existing United States Pharmacopeia (USP) monographs. That material is not necessarily different from material sold for use in dietary supplements. The difference is that a company selling therapeutic quality products must ensure that the botanicals used in these products meet the pharmacopoeial specified identity and quality standards. In contrast, products designated as food grade don’t need to meet the requirements of proving they are medicine.
From a sourcing perspective, the importance of finding therapeutic grade herbs means not just finding a supply of the plant. It means finding growers and collectors who know how to identify or cultivate the plant and how to harvest and process in the correct way at the right time. This is why the open market where you have no knowledge of how the material has been handled is not a reliable source of high quality herbs. It also underscores the importance of establishing longterm relationships with suppliers.
Herbal products that are not formally approved of as botanical drugs do not need to meet the requirements listed in the USP to prove they are medicines. Unfortunately, in order to market a herbal ingredient as a new botanical drug, it must be pre-approved by FDA following a process that is both arduously time consuming and expensive. In the past 15 years, there have only been two botanical drugs that have been approved by FDA. Because of this, the overwhelming majority of herbal products that are used by consumers, patients, and practitioners for therapeutic purposes are sold as herbal dietary supplements. This is the primary reason why it is important to question your manufacturers about the quality control standards they follow, so you know you can have confidence in the products you are getting
For more information, read this overview of the FDA Good Manufacturing Practices, the regulatory baseline for testing and quality control of all herbal products, written by Zoe Gardner, PhD, Research & Development Manager and Herbalist of Traditional Medicinals.
A tremendous amount has been written on the changing regulatory climate for herbal supplements. This topic is far beyond the scope of this website. Below we choose to highlight the identity and quality control and testing standards that are done by companies with rigorous quality control standards.
A series of tests are done to ensure plant identification.
Quality control and testing at Urban Moonshine
TLC plate of linden flower (left), linden reference standard (right), and chemical reference standards of caffeic acid, hyperoside, and rutin (center). The Rf, or retention factor, is a measurement used to ensure that compounds in plants match the reference standards. Photo by Melissa Daoust / Traditional Medicinals.
Batch-to-batch consistency, important for any product, is especially important for products used as medicine. Like quality, it is a huge challenge because plants by their very nature include tremendous variation. The constituents in medicinal plants responsible for healing are often part of a plant’s defense system, and they vary depending on the conditions in which the plants are grown. Plants that are stressed will typically have more of these constituents than those that are not. Thus plants sourced from different locations will likely vary in their potency and strength.
One approach to ensure batch-to-batch consistency is to mix batches with higher amounts of marker compounds with batches that contain less at a specified ratio, thus providing a consistent amount of the marker compounds. Buying from vendors who can produce relatively large lots is another way to ensure uniform consistency of the raw material. Yet, most of the companies we visited also are committed to supporting smaller growers and collectors. All of these costs and objectives must be weighed by a company when developing their sourcing strategy.
Microbial tests at an herbal products company in Poland
This legislation also affects growers, though under the food and not the dietary supplement cGMPs. The technology is still evolving. Right now, steam sterilization is the only allowable type of sterilization under organic certification, and more and more larger companies are now sterilizing all of their raw material. The technology isn’t perfect though. It is a balancing act of not changing the integrity of the plant by using too high of a temperature and using high enough temperatures to kill pathogens. Companies using steam sterilization do pre and post steam tests to compare the reduction log on microbes and the quality and appearance of the plants.