Herbs, Herbal treatment

Introduction

Many herbs have a long history of use and of claimed health benefits. However, some herbs have caused health problems for users. This fact sheet contains points you should consider for your safety if you use, or are thinking about using, herbs for health purposes. It does not discuss whether herbs work for specific diseases and conditions.

What You Should Know:

Are herbal health products and supplements safe because they’re natural?
Not necessarily. Don’t think that herbal health products and supplements are safer than medicines just because they occur in nature or come from plants. After all, many plants are poisonous! Although herbal products and supplements are advertised as “natural,” they aren’t necessarily natural to the human body.

Unlike prescription and over-the-counter (OTC) medicines, herbal products and supplements don’t have to be tested to prove they work well and are safe before they’re sold. Also, they may not be pure. They might contain other ingredients, such as plant pollen, that could make you sick. Sometimes they contain drugs that aren’t listed on the label, such as steroids or estrogens. Some of these products may even contain toxic (poisonous) substances, such as arsenic, mercury, lead and pesticides.

What types of herbal products and supplements are available?
Hundreds of herbal products and supplements are available. They are advertised to treat just about any symptom. However, trustworthy evidence usually doesn’t exist to support these advertising claims.

Some of the most popular herbal products and supplements include chondroitin sulfate, echinacea, ephedra (also called ma huang), garlic, ginkgo biloba, ginseng, glucosamine, kava, melatonin, phytoestrogens (such as black cohosh, dong quai and soy), saw palmetto and St. John’s wort.

Do any health problems increase the danger of taking herbal products and supplements?
Yes. Herbal products and supplements may not be safe if you have certain health problems. You also may be at increased risk of problems from these products if you are elderly. Talk to your doctor before taking herbal products if you have any of the following health problems:

• Blood clotting problems
• Cancer
• Diabetes
• An enlarged prostate gland
• Epilepsy
• Glaucoma
• Heart disease
• High blood pressure
• Immune system problems
• Psychiatric problems
• Parkinson’s disease
• Liver problems
• Stroke
• Thyroid problems
  
  If you are going to have surgery, be sure to tell your doctor if you use herbal products. Herbal products can cause problems with surgery, including bleeding and problems with anesthesia. Stop using herbal products at least 2 weeks before surgery, or sooner if your doctor recommends it.

What are possible side effects of herbal products and supplements?
Many herbal products can cause side effects. Download the PDF file below for some examples of problems that may be caused by herbal products.

Can herbal health products or supplements change the way prescription or OTC drugs work?
Yes. Herbal health products or supplements can affect the way the body processes drugs. When this happens, your medicine may not work the way it should. For example, St. John’s wort reduces the amount of certain drugs absorbed by the body. This may mean the drugs aren’t absorbed at high enough levels to help the conditions for which they are prescribed. This can cause serious problems.

You should be especially cautious about using herbal health products or supplements if you take a drug in one of the following categories:

• Drugs to treat depression, anxiety or other psychiatric problems
• Anti-seizure drugs
• Blood thinners
• Blood pressure medicine
• Heart medicine
• Drugs to treat diabetes
• Cancer drugs
  
  If you take any of these drugs, talk to your doctor before taking any type of herbal product or supplement.

Can herbal health products and supplements cause other problems?
Yes. Herbal products and supplements may have other effects that aren’t listed in the box above.

About Dietary Supplements

Dietary supplements were defined in a law passed by Congress in 1994. A dietary supplement must meet all of the following conditions:

It is a product (other than tobacco) intended to supplement the diet, which contains one or more of the following: vitamins; minerals; herbs or other botanicals; amino acids; or any combination of the above ingredients.

It is intended to be taken in tablet, capsule, powder, softgel, gelcap, or liquid form.

It is not represented for use as a conventional food or as a sole item of a meal or the diet.

It is labeled as being a dietary supplement.

It's important to know that just because an herbal supplement is labeled "natural" does not mean it is safe or without any harmful effects. For example, the herbs kava and comfrey have been linked to serious liver damage.

Herbal supplements can act in the same way as drugs. Therefore, they can cause medical problems if not used correctly or if taken in large amounts. In some cases, people have experienced negative effects even though they followed the instructions on a supplement label. Women who are pregnant or nursing should be especially cautious about using herbal supplements, since these products can act like drugs. This caution also applies to treating children with herbal supplements.

It is important to consult your health care provider before using an herbal supplement, especially if you are taking any medications (whether prescription or over-the-counter). Some herbal supplements are known to interact with medications in ways that cause health problems. Even if your provider does not know about a particular supplement, he can access the latest medical guidance on its uses, risks, and interactions.

If you use herbal supplements, it is best to do so under the guidance of a medical professional who has been properly trained in herbal medicine. This is especially important for herbs that are part of an alternative medical system such as the traditional medicines of China, Japan, or India.

Alternative medical systems are built upon complete systems of theory and practice, and have often evolved apart from and earlier than the conventional medical approach used in the United States. To find out more, see NCCAM's fact sheet "What Is Complementary and Alternative Medicine?"

In the United States, herbal and other dietary supplements are regulated by the U.S. Food and Drug Administration (FDA) as foods. This means that they do not have to meet the same standards as drugs and over-the-counter medications for proof of safety, effectiveness, and what the FDA calls Good Manufacturing Practices.

The active ingredient(s) in many herbs and herbal supplements are not known. There may be dozens, even hundreds, of such compounds in an herbal supplement. Scientists are currently working to identify these ingredients and analyze products, using sophisticated technology. Identifying the active ingredients in herbs and understanding how herbs affect the body are important research areas for the National Center for Complementary and Alternative Medicine.

Published analyses of herbal supplements have found differences between what's listed on the label and what's in the bottle. This means that you may be taking less--or more--of the supplement than what the label indicates. Also, the word "standardized" on a product label is no guarantee of higher product quality, since in the United States there is no legal definition of "standardized" (or "certified" or "verified") for supplements.

Some herbal supplements have been found to be contaminated with metals, unlabeled prescription drugs, microorganisms, or other substances.

Botanical Dietary Supplements:

What is a botanical?
A botanical is a plant or plant part valued for its medicinal or therapeutic properties, flavor, and/or scent. Herbs are a subset of botanicals. Products made from botanicals that are used to maintain or improve health may be called herbal products, botanical products, or phytomedicines.

In naming botanicals, botanists use a Latin name made up of the genus and species of the plant. Under this system the botanical black cohosh is known as Actaea racemosa L., where "L" stands for Linneaus, who first described the type of plant specimen. In the Office of Dietary Supplements (ODS) fact sheets, we do not include such initials because they do not appear on most products used by consumers.

Can botanicals be dietary supplements?
To be classified as a dietary supplement, a botanical must meet the definition given below. Many botanical preparations meet the definition.

As defined by Congress in the Dietary Supplement Health and Education Act (http://www.fda.gov/opacom/laws/dshea.html#sec3), which became law in 1994, a dietary supplement is a product (other than tobacco) that

• is intended to supplement the diet;
• contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents;
• is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and
• is labeled on the front panel as being a dietary supplement.

How are botanicals commonly sold and prepared?
Botanicals are sold in many forms: as fresh or dried products; liquid or solid extracts; and tablets, capsules, powders, and tea bags. For example, fresh ginger root is often found in the produce section of food stores; dried ginger root is sold packaged in tea bags, capsules, or tablets; and liquid preparations made from ginger root are also sold. A particular group of chemicals or a single chemical may be isolated from a botanical and sold as a dietary supplement, usually in tablet or capsule form. An example is phytoestrogens from soy products.

• A tea, also known as an infusion, is made by adding boiling water to fresh or dried botanicals and steeping them. The tea may be drunk either hot or cold.
• Some roots, bark, and berries require more forceful treatment to extract their desired ingredients. They are simmered in boiling water for longer periods than teas, making a decoction, which also may be drunk hot or cold.
• A tincture is made by soaking a botanical in a solution of alcohol and water. Tinctures are sold as liquids and are used for concentrating and preserving a botanical. They are made in different strengths that are expressed as botanical-to-extract ratios (i.e., ratios of the weight of the dried botanical to the volume or weight of the finished product).
• An extract is made by soaking the botanical in a liquid that removes specific types of chemicals. The liquid can be used as is or evaporated to make a dry extract for use in capsules or tablets.

Are botanical dietary supplements standardized?
Standardization is a process that manufacturers may use to ensure batch-to-batch consistency of their products. In some cases, standardization involves identifying specific chemicals (also known as markers) that can be used to manufacture a consistent product. The standardization process can also provide a measure of quality control.

Dietary supplements are not required to be standardized in the United States. In fact, no legal or regulatory definition exists for standardization in the United States as it applies to botanical dietary supplements. Because of this, the term "standardization" may mean many different things. Some manufacturers use the term standardization incorrectly to refer to uniform manufacturing practices; following a recipe is not sufficient for a product to be called standardized. Therefore, the presence of the word "standardized" on a supplement label does not necessarily indicate product quality.

Ideally, the chemical markers chosen for standardization would also be the compounds that are responsible for a botanical's effect in the body. In this way, each lot of the product would have a consistent health effect. However, the components responsible for the effects of most botanicals have not been identified or clearly defined. For example, the sennosides in the botanical senna are known to be responsible for the laxative effect of the plant, but many compounds may be responsible for valerian's relaxing effect.

Are botanical dietary supplements safe?
Many people believe that products labeled "natural" are safe and good for them. This is not necessarily true because the safety of a botanical depends on many things, such as its chemical makeup, how it works in the body, how it is prepared, and the dose used.

The action of botanicals range from mild to powerful (potent). A botanical with mild action may have subtle effects. Chamomile and peppermint, both mild botanicals, are usually taken as teas to aid digestion and are generally considered safe for self-administration. Some mild botanicals may have to be taken for weeks or months before their full effects are achieved. For example, valerian may be effective as a sleep aid after 14 days of use but it is rarely effective after just one dose. In contrast a powerful botanical produces a fast result. Kava, as one example, is reported to have an immediate and powerful action affecting anxiety and muscle relaxation.

The dose and form of a botanical preparation also play important roles in its safety. Teas, tinctures, and extracts have different strengths. The same amount of a botanical may be contained in a cup of tea, a few teaspoons of tincture, or an even smaller quantity of an extract. Also, different preparations vary in the relative amounts and concentrations of chemical removed from the whole botanical. For example, peppermint tea is generally considered safe to drink but peppermint oil is much more concentrated and can be toxic if used incorrectly. It is important to follow the manufacturer's suggested directions for using a botanical and not exceed the recommended dose without the advice of a health care provider.

Does a label indicate the quality of a botanical dietary supplement product?
It is difficult to determine the quality of a botanical dietary supplement product from its label. The degree of quality control depends on the manufacturer, the supplier, and others in the production process.

What methods are used to evaluate the health benefits and safety of a botanical dietary supplement?
Scientists use several approaches to evaluate botanical dietary supplements for their potential health benefits and safety risks, including their history of use and laboratory studies using cell or animal models. Studies involving people (individual case reports, observational studies, and clinical trials) can provide information that is relevant to how botanical dietary supplements are used. Researchers may conduct a systematic review to summarize and evaluate a group of clinical trials that meet certain criteria. A meta-analysis is a review that includes a statistical analysis of data combined from many studies.

Information about some of herbs: