The Everything Guide to Herbal Remedies: An easy-to-use reference for natural health care

CHAPTER 17

Safety and Efficacy

Over the past several years, as interest in complementary and alternative medicine (CAM) and herbal medicine in particular has grown, concerns over the safety (and general advisability) of using herbal remedies has been a subject of great concern. The issues of safety and efficacy go hand-in-hand: Who’d want to use something that isn’t safe? And why bother about the safety of a remedy that isn’t even effective?

Regulation: Who’s Minding the (Herb) Store?

Herbal products are classified as either dietary supplements or cosmetics—not medicines—and therefore are handled differently than drugs by the Food and Drug Administration (FDA).

In 1994, Congress passed the Dietary Supplements Health and Education Act (DSHEA), which expanded the definition of “dietary supplement” to include herbs and other botanicals (anything except tobacco) along with vitamins and minerals. The law requires that food products, cosmetics, and supplements be free of “adulteration” and prohibits them from being “misbranded.” Manufacturers are also required to use safe ingredients: Anything that was available before 1994 is considered safe, and anything that’s been introduced since that time must pass a premarket evaluation by the FDA.

Of course, that’s a far cry from the elaborate approval process that would-be drugs face, a fact that leaves some people questioning the inherent safety of herbal products. But herbs don’t have it any better (or worse) than any other supplement or cosmetic. The government is surprisingly hands-off in its supervision of the popular (and potentially dangerous) products so many of us pop into our mouths or apply to our bodies every day.

There have been several problems in recent years with imported Chinese patent medicines—standardized, ready-to-use preparations that can be contaminated with pharmaceuticals and other dangerous ingredients. To be safe, ask for remedies that have been manufactured in the United States.

Most Americans assume that the products they buy are being closely monitored—and the mere fact that they’re being sold in stores (and not in shady alleyways or on suspicious websites) proves that they’re both safe and effective. But both prescription and over-the-counter (OTC) drugs cause more than a million recorded poisonings—and more than 500 fatalities—every year. And cosmetics can cause problems, too. According to the Environmental Working Group, nearly 90 percent of the ingredients in personal care products have not been assessed for safety, and many products contain ingredients that that are known toxins, such as mercury and lead.

Herbal products, in contrast, are almost never involved in cases of serious toxicity or other ill effects. In fact, the vast majority of poisoning cases involving an herbal product involve accidental ingestion by a young child.

The regulations state that herbal products intended to supplement the diet and taken by mouth (such as pills, capsules, or liquids) are classified as dietary supplements. Products that are used externally for self-care or grooming are considered cosmetics.

The FDA can evaluate products and inspect manufacturing facilities at its discretion, but the agency can step in and try to stop the sale of a product (or take action against the company that’s selling it) only after the product has been shown to be in violation of the law. Imported herbal products must comply with the same regulatory requirements and are subject to search and sampling by the U.S. Customs Service when they arrive in the country.

What Is—and Isn’t—on the Label

Not surprisingly, the government requires very different things from drugs than it does from supplements and cosmetics when it comes to labeling.

Prescription medicines must list the drug’s uses, side effects, and other information. OTC drugs are required to provide similar information, including:


• Product name

• Active ingredients (the therapeutic agents)

• Purpose (the product category, such as “antihistamine”)

• Uses (the symptoms or condition being treated)

• Directions (how much to take, when to take it, etc.)

• Other information (such as storage guidelines)

• Inactive ingredients (binders, flavorings—the nontherapeutic things)

• Net quantity of contents

• Name and address of manufacturer or distributor


Herbs and other supplements can have significantly less on their labels. The FDA requires the following:


• Product name (plus the words “dietary supplement”)

• Nutrition information (a “Supplement Facts” box similar to the “Nutrition Facts” box that’s on food packages, which lists the active ingredients, including the part of the plant from which the ingredient is derived)

• Other ingredients (things that are considered inactive or are nonessential nutrients are listed here, below the Supplements Facts)

• Net quantity of contents

• Manufacturer/distributor information (if the product is imported, the label must disclose the country of origin)


In 2007, the FDA issued new standards, termed Good Manufacturing Practices (GMPs), which require herbals and other supplements to be produced in a quality manner, be free of contaminants or impurities, and contain the exact ingredients (in the exact amounts) listed on the label.

This means that you might not be able to tell much from an herbal product’s label. For example, a bottle of hawthorn (Crataegus monogyna, C. oxyacantha) capsules might include a picture of the herb (a thorny bush covered with white flowers or red berries) but not the condition or body part it’s good for (an ailing human heart). Many manufacturers include dosages and guidelines, but not all do.

What Can This Stuff Do?

Dietary supplements are prohibited from claiming to diagnose, cure, mitigate, treat, or prevent a disease—a bit of regulatory red tape that can leave consumers in the dark. But supplement manufacturers are allowed to make these claims on product labels and in advertising and marketing materials:


• Health claims mention the relationship between an herb or another ingredient and a lowered risk of a particular disease or condition. For example, products containing vitamins E or C may include a statement on how antioxidants can lower your risk of developing cancer.

• Nutrient content claims describe the relative amount of a nutrient or dietary substance in a product. For example, a multivitamin might claim to deliver a full day’s supply of a particular vitamin.

• Structure and function claims describe how a product may affect the organs or systems of the body but can’t mention any specific disease. For example, a calcium supplement’s label might say “Calcium builds strong bones,” but not “Calcium prevents osteoporosis.” Structure and function claims must be accompanied by the disclaimer: “These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.”


While some herbs can interfere with certain medications, most can be used without fear of interactions. In comparison, OTC antacids, which are some of the most widely used drugs in the United States, can interact with a long list of other medications, including many those used to treat acne, diabetes, anxiety, thyroid problems, and—ironically—ulcers.

Other Differences

Beyond the regulatory distinctions, herbs and drugs differ in another big way: While drugs contain a specific amount of specific ingredients, plants—even plants of the same species—can vary quite a bit in their contents.

A plant’s chemical makeup can be affected by many things, including the environment it was raised in, the way it was harvested and processed, and how it was stored. So while a pharmaceutical company can, at least in theory, control every detail of the pills it produces, herbal products manufacturers must leave a lot to nature.

Research and Scientific Proof

It’s been said that herbal medicines and pharmaceuticals arrive at the same destination—the shelf in your neighborhood drug store—from opposite directions. Pharmaceuticals are created in a lab in response to a specific need or to treat a specific condition. Herbs have been around for ages while humans have proceeded, through trial and error, to figure out how to use them.

Preclinical research involves basic science and usually begins with in vitro studies, which are conducted on isolated cells (in vitro means “within the glass” in Latin). In vitro studies gauge a substance’s effects on live tissue.

According to the World Health Organization, ninety-two countries around the world have a system of national regulation for herbal medicines. The United States is one of only a handful of industrialized nations to have no policy. Nearly all countries allow herbals to be sold as OTC drugs, and about half allow herbal medicines to be sold as prescription medicines.

Next, in vivo (or “within the living”) research uses live animals, often mice and rats, to see what the substance does to a living animal.

Human studies, as you might expect, are experiments conducted on people. They can involve epidemiological research, which analyzes data on the use of the herb in a particular group and its relationship to disease and mortality rates, or an analysis of several previously published human trials (called a meta-analysis).

Human research also involves clinical trials, which compare the substance to a drug or other agent or to a placebo, which is a substance with no pharmaceutical effect (a “sugar pill”), to determine its effectiveness. The best trials are double-blind, meaning that neither the subjects nor the test administrators know who is getting the herb and who is getting the other agent or placebo. This eliminates the risk of prejudice.

Because they must go through a much more elaborate process in order to be approved for sale, pharmaceuticals are much more rigorously tested than herbs (remember, it’s much easier to get “dietary supplement” than “drug” status). Thus, the research on many herbs stops at the in vivo stage.

However, there have been several important human clinical trials on herbs in recent years, many of which have shown herbs to be safe and effective alternatives to synthetic drugs.

Other Kinds of Evidence

Of course, herbs do have one big advantage over drugs: They’ve been used safely and successfully for thousands of years. Dose for dose, they are almost always less potent than their pharmaceutical counterparts, meaning they present far less risk of toxicity than drugs do. Many have no known side effects (or very, very mild ones) for people who are otherwise healthy and not taking other medications. Nonetheless, they are medicines and should be treated with care.

Some herbs can interact with cytochrome P450 (CYP), a group of enzymes that are involved in the metabolism of several drugs. There are CYP enzymes that are known to have drug or herb interactions. Be sure to talk with your doctor if you’re taking any medications long term, as they might be on the CYP “potential interactions” list.

The Question of Standardization

Some herbs are standardized for a certain level of an active compound, meaning they’ve been processed in a way that isolates and measures the key constituent or constituents—something that makes it a whole lot easier for consumers to know what they’re buying. However, the issue of standardization is fairly controversial.

Medicinal herbs that are sold in Europe are typically standardized to contain a certain amount of the constituent responsible for their therapeutic effect, also known as the active ingredient or marker. Thus, milk thistle (Silybum marianum) is standardized for Silymarin, the compound that seems to be behind its medicinal effects.

Standardization makes sense for several reasons. From a quality-control standpoint, it allows manufacturers to ensure consistency of their products from batch to batch. It also guarantees that the product contains a therapeutic dose of the medicinal ingredients that made you want to buy it in the first place.

Ideally, the compounds that are used for standardization would be the ones that are responsible for the herb’s beneficial effects. In this way, every time you bought an herb in 250 mg capsules, you’d know exactly how many milligrams of the active ingredient you were getting and what effects you could expect.

But in the majority of cases, the exact compounds that are producing the effect is unknown, meaning you can’t know which ones to pick for standardization. In many cases, we also don’t always know what other compounds, or cofactors, must be present in order for the active constituent to do its job.

Consider Saint John’s wort (Hypericum perforatum), one of the most popular and well-researched herbs around. Scientists continue to debate over which of the plant’s many chemical constituents (there are about sixty) is or are responsible for its medicinal effects. A few years back, everyone seemed to agree that it’s the hypericin, and commercial products standardized for hypericin started appearing. Then researchers began to wonder if another chemical, hyperforin, was the real active ingredient. As of this printing, the jury is still out.

How does Saint John’s wort work?

We know that Saint John’s wort (Hypericum perforatum) works against depression, we’re just not sure how. Most clinical studies have used preparations standardized for 0.3 percent of a chemical called hypericin, but others have used less concentrated products—and others used products standardized for 5 percent of another chemical, hyperforin. Studies on both compounds found beneficial results, leaving the question unanswered.

What’s more, the practice of standardization itself isn’t exactly standardized. Different U.S. manufacturers standardize for different amounts of marker compounds and use different methods of testing.

Meanwhile, many herbalists and natural health practitioners advocate using extracts of the whole herb (or the whole herb part, such as the root) instead of any isolated components. These are called crude extracts. Aside from the question of picking the right ingredient to isolate, they argue that this is the best strategy because herbs have been used for centuries as intact organisms, not individual chemicals, and there’s evidence that the various constituents in herbs work together synergistically.

Unfortunately, this isn’t an ideal solution, either. Because there can be such disparity among crops of plants, there can be enormous variation among their crude extracts—meaning some batches may have higher levels of active constituents than others.

Right now, the best approach seems to be using standardized crude extracts wherever possible. This means you’re getting the whole herb and all of its components but are ensured of getting a therapeutic dose of the active ingredient (or at least the ingredient that seems to be the active one). For more on buying herbal preparations, see Chapter 18.

Medical Concerns

If you have specific health issues, including chronic conditions like diabetes or cardiovascular disease, you should use extra care when taking herbal remedies. If you’re taking medicines as part of a long-term treatment plan, be sure to get your doctor’s approval before using herbs. Some can amplify the effects of medicines and interfere with cytochrome P450 (CYP), an enzyme that’s critical to drug metabolism.

Chronic Conditions

While herbs have been used for centuries to help manage chronic diseases and conditions, you shouldn’t treat yourself. If you have any of the following health concerns, talk with your doctor before using herbal products:


• Blood clotting problems

• Cancer

• Cardiovascular disease (including heart disease and/or hypertension)

• Clinical depression or another psychiatric condition

• Diabetes

• Enlarged prostate

• Epilepsy

• Eye diseases, such as glaucoma

• Immune system problems

• Liver disease

• Parkinson’s disease

• Thyroid disease


Surgery and Anesthesia

If you’re scheduled to have surgery, be sure to talk with your doctor about any herbs you’re taking. In most cases, she will tell you to stop taking them a few weeks before your operation.

Some herbs can interfere with the results of common lab tests. For example, American ginseng (Panax quinquefolius) can conflict with blood glucose tests, and evening primrose (Oenothera biennis) can affect your cholesterol levels (and skew the results of a lipid profile). Talk to your doctor about the herbs you’re taking before scheduling any tests.

Several herbs, including ginkgo (Ginkgo biloba) and turmeric (Curcuma longa), can cause problems during surgery by interfering with the anesthesia or increasing the risk of bleeding.

Prescription and OTC Drugs

Many prescription and OTC drugs can interact with herbal products. Herbs can affect the way your body processes a pharmaceutical agent—and vice versa. For example, Saint John’s wort (Hypericum perforatum) can affect the absorption of certain drugs, increasing the amount that’s absorbed in some cases and reducing it in others (meaning you’re not getting enough of the drug to treat the condition it’s supposed to be treating).

You should talk with your doctor before combining herbs and any pharmaceuticals, but be especially careful if you’re taking any of these:


• Antidepressants, antianxiety drugs, or any other psychotropic medications

• Antiseizure drugs

• Anticoagulant/antiplatelet drugs (also known as blood thinners)

• Antihypertensives

• Heart medicines, such as beta blockers or nitrates

• Cancer drugs

• Diabetes medicines


Special Groups

Pregnant women, young children, and seniors all have special concerns—and should take extra care with herbal medicines.

Pregnancy and Breastfeeding

Some herbs are safe for pregnant and breastfeeding women, while others are known to causes problems. Pregnant and breastfeeding women should not take:


• Black cohosh (Actaea racemosa, Cimicifuga racemosa)

• Dong quai (Angelica sinensis)

• Feverfew (Tanacetum parthenium)

• Goldenseal (Hydrastis canadensis)

• Juniper (Juniperus communis)

• Red clover (Trifolium pratense)

• Kava (Piper methysticum)

• Sage (Salvia officinalis, S. lavandulaefolia)

• Saint John’s wort (Hypericum perforatum)

• Vitex (Vitex agnus-castus)


Pregnant women also should avoid caffeine-containing herbs, such as coffee (Coffea arabica), guarana (Paullinia cupana), mate (Ilex paraguariensis), and tea (Camellia sinensis).

Pregnant women can take these herbs, worry free:


• Ginger (Zingiber officinale)

• Peppermint (Mentha x piperita)

• Psyllium (Plantago ovata, P. psyllium)


In addition, aloe (Aloe vera), cayenne (Capsicum annuum, C. frutescens), gotu kola (Centella asiatica), and witch hazel (Hamamelis virginiana) can be used topically—and safely—during pregnancy.

Any medicine, whether it’s from a pharmacy or a plant, can be passed from a pregnant woman to her unborn baby or from a nursing mother to her infant. Because there’s so little research, some experts advise pregnant and breastfeeding women to avoid taking any herbs orally, with the exception of those specified here.

Babies and Children

Generally speaking, you should stick to herbs with relatively gentle actions when treating children. Don’t treat babies or kids with herbs that work as stimulants, stimulant laxatives, strong sedatives, or phytoestrogens. Don’t give the following herbs to a baby or young child:


• Black cohosh (Actaea racemosa,Cimicifuga racemosa)

• Guarana (Paullinia cupana)

• Red clover (Trifolium pratense)


Many herbs have a long history of being safe for children. They include:


• American ginseng (Panax quinquefolius)

• Echinacea (Echinacea purpurea)

• Flax (Linum usitatissimum)

• Ginger (Zingiber officinale)

• Lemon balm (Melissa officinalis)

• Licorice (Glycyrrhiza glabra)

• Passionflower (Passiflora incarnata)

• Peppermint (Mentha x piperita)

• Psyllium (Plantago ovata, P. psyllium)

• Slippery elm (Ulmus rubra)


In addition, the following herbs are safe for children when applied topically:


• Calendula (Calendula officinalis)

• Lavender (Lavandula angustifolia)

• Rice bran (Oryza sativa)

• Garlic (Allium sativum)

• Goldenseal (Hydrastis canadensis)


Seniors

Many seniors will find that they can use lower doses of many medications—and herbs—as their bodies often process drugs differently than younger people’s bodies do. Talk to your doctor to determine the best dosage.

Many of the prescription and OTC drugs used by seniors can interact with herbs. For example, anticoagulant/antiplatelet drugs—also known as blood thinners—can interact with several herbs, including Asian ginseng (Panax ginseng), dong quai (Angelica sinensis), feverfew (Tanacetum parthenium), garlic (Allium sativum), and ginkgo (Ginkgo biloba).

And the cardiac drug digoxin (Lanoxin, Digitek), also known as digitalis, can interact with several popular herbs, including hawthorn (Crataegus monogyna, C. oxyacantha) and Saint John’s wort (Hypericum perforatum).To be safe, talk with your doctor before using any herbal preparations.

Actions and Interactions

Because they have medicinal properties, herbs should be considered drugs when it comes to interactions. Just as you would do (or should do) when taking prescription or OTC pharmaceuticals, you should make sure that the herbs you’re taking aren’t interfering with any drugs—or with each other.

Herbs with Sedative Properties

Several herbs act as sedatives (they induce relaxation and sleepiness) and can have an additive effect—that is, they’ll increase the action of another agent—when combined with other sedatives, including alcohol.

Don’t combine sedating drugs like antihistamines (including those in antimotion-sickness meds) or insomnia remedies with herbs like gotu kola (Centella asiatica), kava (Piper methysticum), or valerian (Valeriana officinalis), which are sedating on their own. Other sedating herbs include:


• Ashwagandha (Withania somnifera)

• Calendula (Calendula officinalis)

• Chamomile (Matricaria recutita)

• Eleuthero (Eleutherococcus senticosus)

• Gotu kola (Centella asiatica)

• Hops (Humulus lupulus)

• Kava (Piper methysticum)

• Lemon balm (Melissa officinalis)

• Passionflower (Passiflora incarnata)

• Sage (Salvia officinalis, S. lavandulaefolia)

• Valerian (Valeriana officinalis)


The government requires nonprescription products to carry a “Drug Facts” label that includes the active ingredients, uses, warnings, and directions (dosage instructions). Packaged herbals are simply required to list the product’s ingredients on a “Supplement Facts” label (and bulk herbs may have no label at all), meaning you’ll have to do your own research before taking them.

Herbal Stimulants

Several herbs contain caffeine or other chemicals that stimulate the central nervous system. They can have additive effects when combined with other stimulants. They include:


• Asian ginseng (Panax ginseng)

• Cocoa (Theobroma cacao)

• Coffee (Coffea arabica)

• Guarana (Paullinia cupana)

• Mate (Ilex paraguariensis)

• Tea (Camellia sinensis)


Herbs and Blood Sugar

Several herbs work to lower glucose levels, but they can reduce blood sugar too much when combined with diabetes drugs, which do the same thing. Herbs with hypoglycemic potential include:


• Alfalfa (Medicago sativa)

• Aloe (Aloe vera), when used internally

• Asian ginseng (Panax ginseng)

• Bilberry (Vaccinium myrtillus)

• Cinnamon (Cinnamomum verum, C. aromaticum)

• Eleuthero (Eleutherococcus senticosus)

• Eucalyptus (Eucalyptus globulus)

• Fenugreek (Trigonella foenum-graecum)

• Flax (Linum usitatissimum)

• Ginger (Zingiber officinale)

• Horse chestnut (Aesculus hippocastanum)

• Konjac (Amorphophallus konjac, A. rivieri)

• Kudzu (Pueraria lobata)

• Nettle (Urtica dioica)

• Onion (Allium cepa)

• Sage (Salvia officinalis, S. lavandulaefolia)

• Tinospora (Tinospora cordifolia)


Cardioactive Herbs

Several herbs exert a direct effect on heart function, and so should be avoided by anyone with a heart condition (or anyone taking drugs to treat a heart condition). These include:


• Asian ginseng (Panax ginseng)

• Devil’s claw (Harpagphytum procumbens)

• Danshen (Salvia miltiorrhiza)

• Coleus (Coleus forskohlii, Plectranthus barbatus)

• Hawthorn (Crataegus monogyna, C. oxyacantha)


Grapefruit (Citrus paradisi) is used as both a medicinal herb and a breakfast drink, but it can cause big problems if it’s combined with a variety of medications, including oral contraceptives and prescription allergy, anxiety, and insomnia drugs. Doctors suggest you skip the supplemental grapefruit if you’re taking any medications—and wash your medications down with water instead.

Anticoagulant/Antiplatelet Action

Several herbs affect platelet aggregation, or clotting of your blood, and so should be avoided if you’re taking medicines that do the same thing, such as clopidogrel (Plavix) and warfarin (Coumadin). You should discontinue using them at least two weeks before any surgery. They include:


• Andrographis (Andrographis paniculata)

• Asian ginseng (Panax ginseng)

• Borage (Borago officinalis)

• Cayenne (Capsicum annuum, C. frutescens)

• Chamomile (Matricaria recutita)

• Coleus (Coleus forskohlii, Plectranthus barbatus)

• Danshen (Salvia miltiorrhiza)

• Dong quai (Angelica sinensis)

• Eleuthero (Eleutherococcus senticosus)

• Evening primrose (Oenothera biennis)

• Fenugreek (Trigonella foenum-graecum)

• Feverfew (Tanacetum parthenium)

• Flax (Linum usitatissimum)

• Garlic (Allium sativum)

• Ginger (Zingiber officinale)

• Ginkgo (Ginkgo biloba)

• Horse chestnut (Aesculus hippocastanum)

• Kudzu (Pueraria lobata)

• Licorice (Glycyrrhiza glabra)

• Onion (Allium cepa)

• Pineapple (Ananas comosus)

• Red clover (Trifolium pratense)

• Reishi (Ganoderma lucidum)

• Turmeric (Curcuma longa)

• Willow (Salix alba)


Don’t combine OTC decongestants with stimulant herbs like mate (Ilex paraguariensis) or guarana (Paullinia cupana). All of these things can raise your blood pressure and cause other side effects (like increased heart rate, jittery nerves, or irritability).

Hormonal Effects

Some herbs contain chemicals called phytoestrogens that act like the human hormone estrogen. Others affect estrogen levels through different mechanisms. Generally speaking, pregnant and nursing women, men, and children should avoid them, as should anyone with a hormone-dependent disease or condition. You also should use caution when combining them with oral contraceptives. They include:


• Alfalfa (Medicago sativa)

• Black cohosh (Actaea racemosa, Cimicifuga racemosa)

• Dong quai (Angelica sinensis)

• Flax (Linum usitatissimum)

• Kudzu (Pueraria lobata)

• Red clover (Trifolium pratense)

• Saw palmetto (Serenoa repens)

• Soy (Glycine max)

• Vitex (Vitex agnus-castus)


Immunity Modulators

Some herbs can affect your immune system, and therefore shouldn’t be combined with immunosuppressant drugs. They include:


• Alfalfa (Medicago sativa)

• Andrographis (Andrographis paniculata)

• Ashwagandha (Withania somnifera)

• Astragalus (Astragalus membranaceus)

• Cat’s claw (Uncaria guianensis, U. tomentosa)

• Cordyceps (Cordyceps sinensis)

• Elderberry (Sambucus nigra)

• Eleuthero (Eleutherococcus senticosus)

• Maritime pine (Pinus pinaster)

• Neem (Azadirachta indica)

• Reishi (Ganoderma lucidum)

• Tinospora (Tinospora cordifolia)


Immunity Stimulants

Some herbs increase immune function, and shouldn’t be taken by people with autoimmune disorders:


• Barberry (Berberis vulgaris)

• Echinacea (Echinacea purpurea)

• Goldenseal (Hydrastis canadensis)

• Tinospora (Tinospora cordifolia)


Herbs and Hyperlipidemia

Several herbs work to lower cholesterol—and can increase the effect of pharmaceuticals that do the same; they also can skew laboratory lipid test results. They include:


• Alfalfa (Medicago sativa)

• Flax (Linum usitatissimum)

• Garlic (Allium sativum)

• Guggul (Commiphora wightii, C. mukul)

• Hawthorn (Crataegus monogyna, C. oxyacantha)

• Oat (Avena sativa)

• Psyllium (Plantago ovata, P. psyllium)


Herbs and Hypertension

Several herbs have hypotensive effects and so shouldn’t be combined with other blood pressure-lowering agents. They include:


• Andrographis (Andrographis paniculata)

• Cat’s claw (Uncaria guianensis, U. tomentosa)

• Coleus (Coleus forskohlii, Plectranthus barbatus)

• Garlic (Allium sativum)

• Nettle (Urtica dioica)

• Olive (Olea europaea)

• Pomegranate (Punica granatum)

• Reishi (Ganoderma lucidum)

• Valerian (Valeriana officinalis)

• Hawthorn (Crataegus monogyna, C. oxyacantha)


Others can cause a rise in blood pressure. They include:

• Licorice (Glycyrrhiza glabra)

• Sage (Salvia officinalis, S. lavandulaefolia)

• Yohimbe (Pausinystalia yohimbe)

Liver Concerns

Some herbs can adversely affect liver function—they’re potentially hepatotoxic—and shouldn’t be used concurrently. They also shouldn’t be combined with hepatotoxic pharmaceuticals such as acetaminophen (Tylenol). These agents can also interfere with liver function tests and might exacerbate liver problems in some people. Herbs that can affect liver function include:


• Black cohosh (Actaea racemosa, Cimicifuga racemosa)

• Borage (Borago officinalis)

• Butterbur (Petasites hybridus)

• Cinnamon (Cinnamomum verum, C. aromaticum)

• Comfrey (Symphytum officinale)

• Gotu kola (Centella asiatica)

• Kava (Piper methysticum)


The Issues of Allergies

Several medicinal herbs belong to botanical families that, unfortunately, can cause allergies in some people. The Asteraceae/Compositae family contains many medicinal plants—and a few common allergens. If you’re allergic to ragweed, marigolds, or daisies, avoid these herbs:


• Arnica (Arnica montana)

• Artichoke (Cynara cardunculus, C. scolymus)

• Butterbur (Petasites hybridus)

• Calendula (Calendula officinalis)

• Chamomile (Matricaria recutita)

• Dandelion (Taraxucum officinale)

• Echinacea (Echinacea purpurea)

• Eclipta (Eclipta alba, E. prostrata)

• Feverfew (Tanacetum parthenium)

• Milk thistle (Silybum marianum)

• Yarrow (Achillea millefolium)


Salicylic acid is part of a group of chemicals called salicylates, which occur naturally in many plants and are also produced synthetically for use in a variety of consumer products.

Salicylates are everywhere. They can be found in many skin care products, including acne treatments, perfumes, and sunscreens, as well as aspirin, antidiarrheal medications, toothpastes, and OTC sports creams. They’re also in a variety of foods, including berries, red wine, and pine nuts. To someone with sensitivity, even a tiny dose can cause a serious reaction.

Many people are sensitive to salicylates, and so should avoid them in all their incarnations. Skip salicylates if you’re taking prescription blood thinners or diabetes medications. Herbs with salicylates include:


• Cayenne (Capsicum annuum, C. frutescens)

• Cinnamon (Cinnamomum verum, C. aromaticum)

• Clove (Syzygium aromaticum)

• Fenugreek (Trigonella foenum-graecum)

• Ginger (Zingiber officinale)

• Grape (Vitis vinifera)

• Grapefruit (Citrus paradisi)

• Licorice (Glycyrrhiza glabra)

• Peppermint (Mentha x piperita)

• Sage (Salvia officinalis, S. lavandulaefolia)

• Turmeric (Curcuma longa)

• Willow (Salix alba)


How to Stay Safe

Here are a few things to keep in mind when using herbs or herbal products:

• Be informed. Use resources such as this book and the many organizations listed in the Appendices to research the herbs you’d like to use. Be sure to find out about your individual health needs and not just general guidelines.

• Talk to your doctor. Doctors bemoan the fact that very few of their patients talk to them about the herbal products and other supplements they’re using. Even if your doctor isn’t particularly well versed in herbalism, he should know what you’re taking and should be able to advise you accordingly. If you think your doctor isn’t open to the use of herbal remedies, find a different doctor.

• Shop smart. Always buy your herbal products from reputable manufacturers and retailers. Remember that you can’t count on the government to make sure that the products you’re buying are safe and effective.

• Follow the rules. Always obey the manufacturer’s guidelines for dosage. Read the label each time you buy a new supplement, and remember that products can vary widely in concentration. If you can’t find the information on the bottle, look it up.

• Choose your battles wisely. Don’t use an herbal remedy when you need the potency of a pharmaceutical. If you’ve got an active bacterial infection, get the antibiotics. If you’re in agony, get the prescription painkillers. Herbal remedies are effective, but they’re almost always less potent than pharmaceutical drugs.

• Don’t forget … that medicinal agents lurk in many places. For example, alcohol counts as a sedative, so don’t drink if you’re taking an herb or medication with sedating properties. Coffee is a stimulant, garlic is an anticlotting agent, and tea can have diuretic properties.