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 are sometimes called herbal products, botanical products, or phytomedicines.

In naming botanicals, botanists use a Latin name made up of the plant’s genus and a term called the specific epithet. Together, this phrase represents the plant’s species name. For example, the botanical black cohosh is known as Actaea racemosa L., where “L” stands for Linnaeus, who first described this plant. The Office of Dietary Supplements (ODS) fact sheets do not include such initials because they do not appear on the labels of most products used by consumers.

A botanical drug product is intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease in humans.   

• A botanical drug product consists of vegetable materials, which may include plant materials, algae, macroscopic fungi, or combinations thereof. 
• A botanical drug product may be available as (but not limited to) a solution (e.g., tea), powder, tablet, capsule, elixir, topical, or injection. 
• Botanical drug products often have unique features, for example, complex mixtures, lack of a distinct active ingredient, and substantial prior human use. Fermentation products and highly purified or chemically modified botanical substances are not considered botanical drug products.

A botanical drug's special features require consideration and adjustment during the FDA review process. CDER issued a Botanical Drug Development Guidance for Industry to take into consideration these features and to facilitate development of new therapies from botanical sources. The Botanical Guidance applies to only botanical products intended to be developed and used as drugs.

To date, two botanical products have fulfilled the Botanical Guidance definition of a botanical drug product. Both botanical drug products have been approved for marketing as prescription drugs (sinecatechins, Veregen® and crofelemer, Mytesi™).  There are some botanical drugs, including cascara, psyllium, and senna, that are included in the over-the-counter (OTC) drug review.  For a botanical drug substance to be included in an OTC monograph, there must be published data establishing a general recognition of safety and effectiveness, including the results of adequate and well-controlled clinical studies.  

What is a Dietary Supplement?

There are numerous botanical preparations that are marketed in the U.S. as dietary supplements. 

A dietary supplement is a product taken by mouth that contains a dietary ingredient intended to supplement the diet.

The dietary ingredients in these products may include: vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes, organ tissues, glandulars, and metabolites.  

Dietary supplements can also be extracts or concentrates, and may be found in many forms such as tablets, capsules, softgels, gelcaps, liquids or powders.

Dietary supplements can also take other forms, such as a bar. If they do, information on their label must not represent the product as a conventional food or a sole item of a meal or diet.  

Whatever their form may be, the Dietary Supplement Health and Education Act (DSHEA) of 1994, places dietary supplements in a special category under the general umbrella of foods, not drugs and requires that every supplement be labeled a dietary supplement. Dietary supplements are labeled to describe how a nutrient or dietary ingredient affects the structure or function in humans or to describe the documented mechanism by which a nutrient or dietary ingredient acts to maintain the structure or function.  The labeling on a dietary supplement can not make a disease claim to diagnose, cure, mitigate, treat or prevent disease.

To be classified as a dietary supplement, a botanical must meet the definition of a dietary supplement as defined by Congress in the Dietary Supplement Health and Education Act of 1994. This act states that 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, or other substances) or their constituents
• Is intended to be taken by mouth as a pill, capsule, tablet, or liquid
• Is labeled as a dietary supplement

Botanicals are sold in many forms as both fresh and dried plant materials. For example, a supermarket's produce aisle carries fresh ginger root, while dried ginger root may be found in the dietary supplement aisle in capsule or tablet form, in tea bags, or as a liquid preparation. A group of chemicals or a single chemical may also be isolated from a botanical and sold as a dietary supplement, usually in tablet or capsule form. For example, phytoestrogens from soy products are sold as dietary supplements.

Common ways to prepare botanicals for use include teas, infusions, decoctions, tinctures, and extracts:

• A tea is made by adding boiling water to fresh or dried botanicals and steeping them. An infusion is a very strong tea. Teas and infusions may be consumed hot or cold.
• Some roots, bark, and berries require more forceful treatment to extract their desired constituents. They are added to water which is brought to a boil and then simmered at lower heat for several minutes. This also reduces the volume of liquid, producing a more concentrated preparation. Decoctions may be consumed hot or cold.
• A tincture is made when a botanical is soaked in a solution of alcohol and water. Tinctures are sold in liquid form and are used for concentrating and preserving a botanical. They are available 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 when the botanical is soaked in a specific liquid, such as water or alcohol, to extract the desired constituents. The extract can be used after the soaking, or it can be evaporated to make a dry extract for use in capsules or tablets.

Standardization is a process that manufacturers may use for extracts to ensure that all of their batches are similar. The standardization process involves identifying and measuring specific chemicals (also known as markers) and adjusting them to assure consistent amounts in each batch.

Ideally, the chemical markers chosen for standardization would also be the constituents that are responsible for a botanical’s effect in the body. If such chemical markers were used, each batch of the product would have the same health effects. However, the constituents responsible for the effects of most botanicals are not known. For example, the sennosides in the botanical senna are responsible for its laxative effect, but many constituents may be responsible for valerian’s relaxing effect.

U.S. law does not require dietary supplements to be "standardized." In fact, there is no legal or regulatory definition of the term in the United States.

Some people believe that products labeled “natural” are safe and good for them. This belief is not necessarily correct 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 amount used.

The actions of botanicals range from mild to powerful. A botanical with mild action might have subtle effects. Chamomile and peppermint, for example, are usually consumed in teas to help with digestion and are generally considered safe for most people. Some botanicals with mild action might need to be taken for weeks or months before their full effects are achieved. For example, valerian might help users sleep better after a few weeks of use, but just one dose is rarely effective. In contrast, a powerful botanical produces a fast result. Green tea (a natural source of caffeine) and yohimbe, for example, can have strong and immediate stimulant effects.

The dose and form of a botanical preparation also play important roles in its safety. Teas, tinctures, and extracts have different strengths from one another. For example, the same amount of a botanical may be contained in a cup of tea, a few teaspoons of tincture, or an even smaller amount of an extract. Also, different preparations have different amounts and concentrations of constituents extracted from whole botanicals. For example, peppermint tea is generally considered safe to drink, but peppermint oil is much more concentrated and can be toxic if used incorrectly.

Follow the manufacturer’s suggested directions for using a botanical and do not exceed the recommended dose unless your health care provider directs otherwise. In fact, you should always talk with your health care provider about botanical and other dietary supplements that you are using or are thinking of using.

Determining the quality of a botanical dietary supplement product from its label is difficult. The degree of quality control depends on the manufacturer and others in the production process. The presence of terms such as "standardized", for example, does not necessarily indicate that the product is of high quality.

The U.S. Food and Drug Administration (FDA) has established good manufacturing practices (GMPs) that dietary supplement manufacturers must follow to help ensure the identity, purity, strength, and composition of their dietary supplements. These GMPs can prevent the use of the wrong ingredient (or too much or too little of the right ingredient) and reduce the chance of contamination or improper packaging and labeling of a product. The FDA periodically inspects facilities that manufacture dietary supplements.

Several independent organizations offer quality testing and allow products that pass these tests to display a seal of quality assurance. These seals indicate that a product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. However, these seals do not guarantee that a product is safe or effective. Organizations that offer quality testing include:

• ConsumerLab.com
• NSF International
• U.S. Pharmacopeia

Scientists can use many approaches to evaluate the potential health benefits and risks of botanical dietary supplements. For simple single-ingredient products, they can investigate the history of the botanical’s use. They can also conduct laboratory studies of the botanical’s effects on cell or tissue cultures, or examine its effects in animals. Studies with people (for example, individual case reports, observational studies, and clinical trials) provide the most direct evidence of a botanical supplement’s effects on health and how people are using it. These studies are important, especially for complex multi-ingredient products.

The amount of scientific evidence available on the health effects and safety of botanical ingredients varies widely. For example, scientists have conducted numerous studies (with mixed results) on the use of black cohosh to treat menopausal symptoms, including hot flashes and night sweats. On the other hand, very little research has been done on some botanical ingredients, such as astragalus, to determine their value.

Through the Consortium for Advancing Research on Botanical and Other Natural Products (CARBON) Program, ODS promotes research on the safety, effectiveness, and mechanisms of action of botanical dietary supplements with high potential to benefit human health. The CARBON program also supports the development of methods and resources to enhance the progress of this research.

Medicines must be evaluated for safety and efficacy and receive FDA approval before they can be sold or marketed, but dietary supplements, including botanicals, do not require FDA approval. The FDA requires supplement companies to have evidence that their products are safe, and claims on product labels must be truthful and not misleading.

About one in five U.S. adults takes botanical supplements, and sales of these products continue to grow. Like other dietary supplements, botanical supplements have not been shown to prevent or treat COVID-19, but do they have other health benefits? Are they safe? And how can you identify a quality product?

Many people have questions about botanical supplements, so we’ve provided some answers below.

What are botanical supplements and how do they differ from other supplements like fish oil, probiotics, melatonin, and vitamin D?

The term “botanical” means “plant,” so botanical supplements contain one or more parts of plants, like the roots of black cohosh or the flowers of echinacea. Botanical supplements, which are often called herbal supplements, are all classified as dietary supplements and they are regulated by the U.S. Food and Drug Administration (FDA) differently than over-the-counter or prescription medicines. Medicines must be approved by FDA before they can be sold or marketed, but dietary supplements do not require this approval.

What forms of botanicals are available?

Botanicals are sold in many forms as both fresh and dried plant materials. For example, a supermarket’s produce aisle carries fresh ginger root. Dried ginger root may be found in the spice aisle or in the dietary supplement section in capsule or tablet form, in tea bags, or as a liquid preparation. One or more natural plant constituents may also be isolated from a botanical and sold in concentrated form as a dietary supplement, usually in a tablet or capsule. For example, phytoestrogens from soy products are sold as dietary supplements.

Do botanical supplements work and are they safe?

The amount of scientific evidence on the health effects of botanical supplements varies widely. Because botanical supplements do not require FDA pre-market approval, manufacturers do not have to prove to FDA that their products “work” before selling them. In addition, botanicals aren’t necessarily safe just because they are “natural.” The safety of a botanical depends on many things including its chemical makeup, how it is prepared, the amount used, and whether it is taken with other supplements.

Some botanicals, like St. John’s wort, have been well studied, so scientists know a lot about their safety and effectiveness. Others, like cat’s claw, have not. In addition, botanical supplements can interact with medications, so if you take any medications, check with your healthcare provider.

What does the term “standardized” mean on a product label?

Manufacturers of botanical supplements can identify and measure specific chemical constituents in their products, often called “markers,” and adjust them to ensure consistent batches. This process is called standardization. However, the constituents responsible for the health effects of most botanicals are not known. In addition, the term “standardized” has no legal or regulatory definition in the United States. Therefore, products labeled as “standardized” aren’t necessarily more effective, safe, or of higher quality than others.

How can I find high-quality botanical supplements?

Determining the quality of a botanical supplement can be difficult because quality depends on the manufacturer and the production process. Your healthcare provider might be able to recommend a specific brand.

A product’s label doesn’t necessarily indicate quality, but you can look for seals of quality assurance from several independent organizations that offer quality testing. These seals indicate that a product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. These seals, however, do not guarantee that a product is safe or effective.

What’s the bottom line?

Gather as much information as you can from reliable sources and talk with your healthcare provider for advice. If you decide to try a botanical supplement, follow the manufacturer’s suggested directions for use and do not exceed the recommended dose unless your healthcare provider recommends otherwise. Always be alert to the possibility of a bad reaction. If you think that you had a bad reaction, tell your healthcare provider.

Many natural products sold as dietary supplements are marketed for promoting health and well-being and preventing disease. However, there is often little to no evidence to support these claims. Here are five myths about popular natural products often used for disease prevention and wellness reasons and what the science really says about them for improving health.

Remember, take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

1. Myth: Herbs such as valerian, chamomile, and kava are effective for insomnia.
   Fact: Various herbs such as valerian, chamomile, and kava, and homeopathic medicines sometimes used as sleep aids have not been shown to be effective for insomnia, and important safety concerns have been raised about a few. For example, kava supplements have been linked to a risk of severe liver disease. However, there is evidence to suggest that using relaxation techniques, such as progressive relaxation, guided imagery, biofeedback, or deep breathing exercises, before bedtime can be helpful components of a successful strategy to improve sleep habits. Current evidence also suggests that melatonin may be useful in treating several sleep disorders, including jet lag, delayed sleep phase disorder, and sleep problems related to shift work.

2. Myth: The herb passionflower can reduce stress and improve overall health.
   Fact: There are very few studies of passionflower conducted in people and therefore insufficient evidence to determine whether passionflower is efficacious for any condition. However, there is some scientific evidence to date that suggests mindfulness meditation—a mind and body practice which cultivates abilities to maintain focused and clear attention, and develop increased awareness of the present—may help reduce symptoms of stress, including anxiety and depression. Results from a small body of research suggest that yoga may also affect stress and anxiety symptoms.

3. Myth: A daily dose of a vitamin C supplement will prevent the onset of the common cold.
   Fact: Several reviews have concluded that prophylactic vitamin C does not reduce the incidence of colds in the general population, but may be useful in reducing incidence of colds for people exposed to brief periods of severe physical exercise (e.g., marathon runners, skiers, and soldiers training in subarctic conditions). 

4. Myth: Taking garlic supplements will prevent heart disease.
   Fact: There is no evidence that garlic supplements prevent heart disease. However, evidence from small studies is mixed about whether garlic supplements reliably lower cholesterol levels or change other known risk factors for cardiovascular disease.

5. Myth:Turmeric (curcumin) and Ginkgo biloba supplements can prevent the onset of dementia and Alzheimer’s disease in people.
   Fact: Although there is some evidence in laboratory studies that curcumin may affect brain function and the development of dementia, these results have not been demonstrated in clinical trials. In several large clinical trials, Ginkgo biloba has not been shown to effective in reducing either the overall incidence rate of dementia or Alzheimer’s disease incidence.

Background Information

Botanical dietary supplements, sometimes called herbals or herbal dietary supplements, are products made from plants, plant parts, or plant extracts. They are meant to be consumed and contain one or more ingredients meant to supplement the diet. One recent nationwide government survey found that natural products, including dietary supplements, are used by approximately 18% of adults.

Botanical dietary supplements are used in both traditional and complementary medicine, and take many forms, including:

• Tablets
• Capsules
• Softgels
• Gelcaps
• Liquids
• Powders

Echinacea, green tea extract, garlic, and evening primrose oil are common examples of botanical dietary supplements used for health.

If a manufacturer wants to distribute a supplement containing a new dietary ingredient, they first must notify the U.S. Food and Drug Administration (FDA) before it can be sold. But notifying the FDA doesn't mean the FDA deems the ingredients or supplement as safe. The FDA is only responsible for taking action against products found to be harmful after they have started selling in the market.

NTP has received multiple nominations from the public and other federal agencies to study various botanical dietary supplements. This research is not concerned with the benefits of the supplement. Instead, NTP studies are designed to identify any potential harm from short and long-term exposure to these substances.

NTP Studies

NTP is conducting multiple studies to identify the potential harm of short and long-term exposure to botanical dietary supplements. These studies may provide toxicology data and help in determining the safety or risk of certain supplements. This data can be used by:

• U.S. Food and Drug Administration
• National Institutes of Health
• Public
• Health care providers
• Foreign Governments
• Other stakeholders

Below are NTP's ongoing and completed studies, each with a link to the testing status page, any recent updates, and any available reports.

Ongoing NTP Studies

Completed NTP Studies

Q. What are botanical supplements and how do they differ from other supplements like fish oil, probiotics, melatonin, and vitamin D?

A. The term “botanical” means “plant,” so botanical supplements contain one or more parts of plants, like the roots of black cohosh or the flowers of echinacea. Botanical supplements, which are often called herbal supplements, are all classified as dietary supplements and they are regulated by the U.S. Food and Drug Administration (FDA) differently than over-the-counter or prescription medicines. Medicines must be approved by FDA before they can be sold or marketed, but dietary supplements do not require this approval.

Q. What forms of botanicals are available?

A. Botanicals are sold in many forms as both fresh and dried plant materials. For example, a supermarket’s produce aisle carries fresh ginger root. Dried ginger root may be found in the spice aisle or in the dietary supplement section in capsule or tablet form, in tea bags, or as a liquid preparation. One or more natural plant constituents may also be isolated from a botanical and sold in concentrated form as a dietary supplement, usually in a tablet or capsule. For example, phytoestrogens from soy products are sold as dietary supplements.

Q. Do botanical supplements work and are they safe?

A. The amount of scientific evidence on the health effects of botanical supplements varies widely. Because botanical supplements do not require FDA pre-market approval, manufacturers do not have to prove to FDA that their products “work” before selling them. In addition, botanicals aren’t necessarily safe just because they are “natural.” The safety of a botanical depends on many things including its chemical makeup, how it is prepared, the amount used, and whether it is taken with other supplements.

Some botanicals, like St. John’s wort, have been well studied, so scientists know a lot about their safety and effectiveness. Others, like cat’s claw, have not. In addition, botanical supplements can interact with medications, so if you take any medications, check with your healthcare provider.

Q. What does the term “standardized” mean on a product label?

A. Manufacturers of botanical supplements can identify and measure specific chemical constituents in their products, often called “markers,” and adjust them to ensure consistent batches. This process is called standardization. However, the constituents responsible for the health effects of most botanicals are not known. In addition, the term “standardized” has no legal or regulatory definition in the United States. Therefore, products labeled as “standardized” aren’t necessarily more effective, safe, or of higher quality than others.

Q. How can I find high-quality botanical supplements?

A. Determining the quality of a botanical supplement can be difficult because quality depends on the manufacturer and the production process. Your healthcare provider might be able to recommend a specific brand.

A product’s label doesn’t necessarily indicate quality, but you can look for seals of quality assurance from several independent organizations that offer quality testing. These seals indicate that a product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants. These seals, however, do not guarantee that a product is safe or effective.

Q. I get colds a lot, and I’ve thought about trying echinacea. Since it’s a natural herb, it should be safe, right?

A. Not necessarily. Even though herbal products, such as echinacea, are “natural,” that doesn’t mean that they are always safe or good for you. The safety of an herbal supplement depends on many things, such as its chemical makeup, how it works in the body, how it’s prepared, and how much you take. Many supplements contain active ingredients that can have strong effects in the body and can interact with certain prescription drugs in ways that might cause problems.

Always be alert to the possibility of unexpected side effects, especially when taking a new product. Echinacea does not usually cause serious side effects, although it sometimes causes nausea, stomach pain, diarrhea, or vomiting, and allergic reactions can occur.

Unfortunately, study results on echinacea are mixed, so it is not clear at this time whether echinacea prevents or treats upper respiratory tract infections, such as the common cold.

Q. Is valerian a “natural” form of Valium®? And if so, how much should I take?

A. Although their names are similar, valerian and Valium are not related to each other. Valium is a medication available only by prescription. It is the brand name for the drug diazepam which is used to treat anxiety, panic attacks, and other conditions.

Valerian is an herb that is sold as a dietary supplement. It is found in some products promoted as mild sedatives and sleep aids, although it is not clear to what extent valerian is helpful for these conditions. Valerian, like all dietary supplements, should not be taken in place of, or in combination with, prescribed medications without your health care provider’s approval.

Like many herbs, scientists are not certain which components of valerian are responsible for its effects. Dietary supplements are not required to be standardized in the United States, so formulations of valerian products may vary. Therefore, it can be difficult to compare one valerian product with another and determine appropriate doses. We recommend talking with your health care provider for advice.

Q. I have been taking a prescription antidepressant but want to try something more natural. A friend told me about St. John’s wort, but I’ve read that it can have side effects. How is this possible since it’s from a plant?

A. Even though dietary supplements from herbs and other plants are “natural,” they can still have side effects. They also can interact with prescription or over-the-counter medications. St. John’s wort can cause sensitivity to sunlight and other side effects including dry mouth, dizziness, and headache. It also interacts with a lot of medications including antidepressants, birth control pills, digoxin (a heart medication), indinavir (used to treat HIV/AIDS), and anticoagulants such as warfarin. St. John’s wort usually causes the body to process the medication faster than normal, leading to medication levels that are too low. And taking St. John’s wort with certain antidepressants can lead to a potentially life-threatening increase in serotonin, a naturally occurring substance in the body that helps regulate brain function. Always tell your healthcare providers (including doctors, pharmacists, and dietitians) which dietary supplements you’re taking so that you can discuss what’s best for your overall health.

Q. My doctor has told me to avoid dietary supplements—especially herbal products—because they haven’t been tested to see if they’re safe and effective. Many people take them or want to try them, so why hasn’t there been more research?

A. Dietary supplements are intended to “supplement the diet;” they’re not intended to treat or prevent diseases. Unlike drugs, dietary supplements don’t have to undergo premarket review or approval by the U.S. Food and Drug Administration (FDA)—a step that requires a great deal of research—before they become available to the public.

Nevertheless, many dietary supplements can have strong effects in the body, and we recognize that more research is needed on these products. That’s one of the reasons we have initiated programs like the Consortium for Advancing Research on Botanical and Other Natural Products (CARBON) program in partnership with the National Center for Complementary and Integrative Health. The CARBON program promotes collaborative, transdisciplinary research on the safety, effectiveness and mechanisms of action of botanical dietary supplements and also supports the development of methods and resources that will enhance the progress of this research.