FAQs about herbal products
There are so few credible reports of unexpected side effects due to herbal products that most experts consider problems with herbal products to be of only minor or occasional concern. Before his death in 2011, Norman Farnsworth, Director of the World Health Organization Collaborating Centre for Traditional Medicine and Research Professor of Pharmacognosy at the University of Chicago at Illinois, was generally considered to be one of the most respected experts on the scientific research of botanical medicines. In an article written on the subject of herbal safety,(9) Dr. Farnsworth concluded, "...side effects or toxic reactions associated with herbal medicines in any form are rare. In fact, of all classes of substances reported to cause toxicities of sufficient magnitude to be reported in the United States, plants are the least problematic." This is not to say that every herbal ingredient that is sold as an ingredient in a supplement is appropriate for every consumer or in any quantity. Responsible and informed use by consumers is essential to ensure that herbal products maintain their established safety profile. Accurate product labeling must provide consumers with all information that is material to the use of the product, and such disclosure is required by Federal law.(10)
To assist in assuring that herbal manufacturers provide material information about their products, the American Herbal Products Association (AHPA) has developed specific labeling guidelines for a number of botanical ingredients. Labeling recommendations exist for products containing chaparral (Larrea tridentata); comfrey (Symphytum spp.); kava (Piper methysticum); saw palmetto (Serenoa repens); and St. John's wort (Hypericum perforatum), among others. In addition, AHPA published an entire volume of information related to established herbal safety concerns, entitled Botanical Safety Handbook.(11) This reference classifies over 500 herbs with safety categories that can assist both manufacturers in their labeling and consumers in making informed choices in their use of herbs. A general rule for assuring responsible use of an herbal product is to follow all of the labeled directions. If the product bears a caution that suggests that the product is inappropriate for your use, you should take that message seriously. More information can often be provided by a qualified expert, and often from well-informed retail personnel.
But can a consumer have confidence in the claims made for the products that are available in the market? To begin with, Federal labeling law and regulations for supplements limit allowable claims to those for which a manufacturer "has substantiation that such statement is truthful and not misleading."(14) The manufacturer therefore has a legal burden to assure that the claim that is made for their products has scientific evidence to back it up. Because there is a greater acceptance of herbal therapies by conventional physicians in Europe, a significant body of clinical data supporting the use of herbs has been developed there. More recently, a number of U.S. companies have designed clinical studies for their branded products. It is estimated that there are over 1,000 clinical trials now being undertaken in the U.S. to increase our knowledge about herbs. The National Institutes of Health has even set up a center with a special focus on "alternative" medicine, and is now concentrating much of its resources on the study of herbal products.
Herbs are rich mixtures of diverse natural compounds. Although the effects of certain herbs will be observed within a short time after consumption, others are more subtle and provide their health promoting benefits gradually. If you have ever used ginger root (Zingiber officinale) or peppermint leaf (Mentha x piperita) tea to promote healthy digestion, you know that you can feel the comforting effects of these herbs almost as you drink the soothing brew. The sense of well-being that results from the use of kava root (Piper methysticum) should manifest in only a short time when using a well manufactured product. Similarly, all of the herbs that contain anthrones — such as rhubarb root (Rheum spp.) or cascara sagrada bark (Frangula purshiana) — will produce a laxative effect within a half a day or so.
Other herbs are known to produce noticeable benefits only after several days or weeks. For example, improvement in sleep when using an extract of valerian root has been shown to be somewhat dependent on continued use.(13) With saw palmetto (Serenoa repens), the berries of which are used to promote the health of the prostate, the full benefits have been shown in one study to be achieved after 12 to 18 months.(15) Other herbs, such as those that are rich in antioxidants, work to improve your health without a noticeable effect. For more information about what to expect from an herbal product (and when to expect it), consult with the product's manufacturer or an herbal health practitioner. You can find a regional list of herbalists the American Herbalists Guild's professional member referral list at http://www.americanherbalistsguild.com, or your local acupuncturist at the American Association of Oriental Medicine http://www.aaom.org.
Like foods, supplements must provide consumers with nutritional information. Unlike foods, supplements must state the quantity of each of the contained ingredients, or of the "proprietary blends" that make up a product. All herbal products are required to identify the parts used of each of the plant ingredients, and to label them with their commonly accepted names. One of the areas of the most detailed Federal regulation of supplements is in the area of product claims, whether on product labels or in advertising. The Food and Drug Administration specifies exactly what kind of claims are allowed, and prohibits the use of any statement that would brand the product as a drug.(21) Herbal supplements are not allowed to make statements regarding prevention, cure, mitigation or treatment of diseases. Instead, their claims are limited to statements that are legally defined as "statements of nutritional support" or "structure/function statements."
Unfortunately, some uninformed writers have published statements that infer that the entire supplement industry is unregulated. Although this unfortunate "fact" has been broadly reported, it is absolutely false.
Similar information has surfaced about some of the herbs that we use. For example, we now know that the use of an extract of St. John's wort (Hypericum perforatum) may cause certain prescription medications to be eliminated more quickly,(26, 27) leading one researcher to caution that, "As with grapefruit juice, a food product, physicians should also be aware of potential drug-herb interactions."(26) In response to this new information, the American Herbal Products Association has recommended that products containing St. John's wort be labeled to suggest that the advice of your prescribing physician be requested if you are taking any prescription drugs. Speculation on the exact mechanism of St. John's wort has led to reports that the use of this herb might affect oral contraceptives, leading to ineffectiveness and unwanted pregnancies. To date, there have been no reports of any such actual occurrence. Nevertheless, women taking oral contraceptives such as ethinyl estradiol and desogestrel should be aware that, if you experience break-through bleeding, you might experience a reduction in protection against pregnancy.
As can be seen by the above examples, the effect of a drug can be either increased or decreased in the presence of other factors in the diet, including herbal use. Although it is likely that most such factors have little or no influence on drug metabolism, continued research will add to our knowledge of such interactions and responsible food and supplement manufacturers will be expected to inform their customers of any new findings. There is now an ongoing interest in other drugs that are suspected of interacting with certain specific herbs, with most contemporary emphasis on the use of herbs with blood-thinning drugs such as warfarin. Although the current concerns are either conceptual or based on isolated and inconclusive reports, it is advisable to inform your prescribing physician or pharmacist that you are using herbs when undergoing any drug therapy. As close monitoring of the effect of warfarin is an established standard of medical practice, this additional information will assist your physician in maintaining good supervision of your drug levels. In order to understand the potential for an herbal product to interact with prescription drugs, it may also be useful to consult with a qualified herbal expert. You can find a regional list of herbalists the American Herbalists Guild's professional member referral list at http://www.americanherbalistsguild.com, or your local acupuncturist at the American Association of Oriental Medicine http://www.aaom.org. A similar database of naturopathic physicians is maintained by the American Assoc. of Naturopathic Physicians at http://naturopathic.org.
With regard to choosing a brand, one recommendation is to only purchase products from companies who are members of the American Herbal Products Association (AHPA). All of AHPA's members agree to abide by a Code of Ethics that requires adherence not only to established regulations, but also to meaningful industry policies. Thus, certain business practices that are not mandated by any government agency are expected of all of these companies. One such measure, established as an industry regulation in 1992, called upon all of AHPA's members to agree to a single standardized common name for each of the herbs used in their products to ensure clear labeling for consumers. This policy has now been adopted as Federal law. Links to many of AHPA's members and a copy of the Association's Code of Ethics are on this website. It is also generally recommended that you buy your herbal product from a reputable company. If the claims made on a particular product are outrageous and unbelievable, especially when compared to other products with the same or similar ingredients, that may be an indication to try another brand. Consider the advice of your retailer, and always feel free to contact the marketer. Those who are selling high quality products will be happy to answer all of your questions and provide you with the assurances that you, their customer, deserve.
Finally, if you have purchased a product that works for you and that provides the promised benefits, stick with it, whether it's a tablet, tincture or tea, whether a single herb or a complex formulation of several herbs. And remember — a brand that is remarkably less expensive than other products with the same or similar ingredients is not always the best bargain.
The goal in standardizing an extract is to control the complete chemical composition of the extract, rather than one particular identified constituent or group of constituents. The heightened interest in standardized products is due to the belief that standardization is directly related to the potency of the extract. This is not necessarily the case and can unfortunately lead to a "more is better" perception. It is important to know that the use of marker compounds is not essential to the production of quality botanical products and that many companies market high quality and consistent herbal extracts without reference to these. In addition, any manufacturing process that is too specifically concentrated on maximizing one constituent may place an undue emphasis on that single compound. On the other hand, there can be value in a manufacturing process that implements measures to control the entire spectrum of an herb's constituents and that also includes attention to marker compounds. Consumers should understand that label information about markers is usually provided to communicate product consistency and a degree of quality control rather than potency.
AHPA also has basic information about a number of specific ingredients — willow, valerian, St. John's wort, ginkgo, ginger and echinacea — available online through our Another Healthy Herb educational initiative.
And A Field Guide to Herbal Dietary Supplements, a .pdf booklet available on the AHPA Foundation for Education and Research on Botanicals Web site, also provides basic information about herbal products and more details about eight species.
Please browse AHPA’s bookstore for a variety of books on herbs.
2. Anon. 2000. Consumer Use of Dietary Supplements. A Publication of Prevention Magazine.
3. Akerele, O. 1992. WHO Guidelines for the Assessment of Herbal Medicines. Fitoterapia 63(2):99-104.
4. The broad category of "dietary supplements" was legally defined in 1994 by Congress' unanimous passage of a law called the Dietary Supplement Health and Education Act, or DSHEA.
5. Schultes, RE and RF Raffauf. 1990. The Healing Forest.
6. Garrison, J. Two Toddlers Died from Oleander Poisoning, Coroner Says. Los Angeles Times: July 26, 2000.
7. Federal Food, Drug & Cosmetic Act, Section 301(a).
8. Federal Food, Drug & Cosmetic Act, Section 350b(a)(2).
9. Bennett, J. and CM Brown. 2000. Use of Herbal Remedies by Patients in a Health Maintenance Organization. Journal of the American Pharmaceutical Association 40(3):353-358.
10. Farnsworth, NR. 1993. Relative Safety of Herbal Medicines. HerbalGram 29.
11. Federal Food, Drug & Cosmetic Act, Section 201(n).
12. McGuffin, M., C. Hobbs, R. Upton, and A. Goldberg. 1997. Botanical Safety Handbook. Boca Raton, FL: CRC Press. Available from AHPA.
13. Leathwood, PD, et al. 1982. Aqueous extract of valerian root (Valeriana officinalis L) improves sleep quality in man. Pharmacol Biochem Behav 17(1):65-71.
14. Donath, F, et al. 2000. Critical evaluation of the effect of valerian extract on sleep structure and sleep quality. Pharmacopsychiatry 33(2):47-53.
15. The Dietary Supplement Health and Education Act of 1994, Public Law 103-417, 103rd Congress
16. Donath, F., et al. 2000. Critical evaluation of the effect of valerian extract on sleep structure and sleep quality. Pharmacopsychiatry 33(2):47-53.
17. Bach, D. and L. Ebeling. 1996. Long-term drug treatment of benign prostatic hyperplasia - results of a prospective 3-year multicenter study using Sabal extract IDS 89. Phytomedicine 3(2):105-111.
18. Federal Food, Drug & Cosmetic Act, Section 402(f).
19. Government Printing Office. 2000. Title 21 Code of Federal Regulation, Section 101.36. There are exemptions to the requirement for labeled "Supplement Facts," which includes a statement of serving size, for specifically identified small businesses and for foods in small packages. Exempt manufacturers nevertheless generally provide information about recommended serving.
20. Government Printing Office. 2000. Title 21 Code of Federal Regulation, Section 110. "Current good manufacturing practice in manufacturing, packing, or holding human food."
21. Government Printing Office. Revised Feb. 7, 2000. Title 21 Code of Federal Regulation, Section 101.93. "Certain types of statements for dietary supplements."
22. Henney, J. Statement By Jane E. Henney, MD, Commissioner, Food And Drug Administration, Department Of Health And Human Services, Before The Committee On Government Reform, U.S. House Of Representatives. March 25, 1999.
23. Bailey DG, et al. 1991. Interaction of citrus juices with felodipine and nifedipine. Lancet 337(8736):268-9.
24. Bailey DG, et al. 1998. Grapefruit juice-drug interactions. Br J Clin Pharmacol 46(2):101-10
25. Wells, PS, et al. 1994. Interactions of warfarin with drugs and food. Annals of Internal Medicine 121(9):676-83.
26. Johne A, et al. 1999. Pharmacokinetic interaction of digoxin with an herbal extract from St. John's wort (Hypericum perforatum). Clin Pharmacol Ther 66(4):338-45.
27. Piscitelli SC, et al. 2000. Indinavir concentrations and St John's wort [letter]. Lancet 355(9203):547-8.
28. Some concern has been stated regarding a conceptual danger in "unknown" herbal combinations. This point of view is apparently uninformed about the historic acceptance of herbal formulas, and is no more relevant to herbal ingredients combined in a supplement product than it would be to the creation of an innovative recipe in your kitchen.
29. Indeed, there is a common misconception in the U.S. that standardization is equivalent to adding purified compounds to an herb in order to achieve a desired level of the marker compound. In fact, nothing could be further from the truth. The addition of purified compounds in order to achieve "standardization" actually defeats the purpose of standardization.