Learn About Common Herbal Supplements

What Are Herbal Supplements and How Do They Differ From Medications

Herbal supplements are products made from plants, plant parts, or plant extracts. They come in many forms including pills, capsules, powders, liquids, and teas. Unlike prescription medications and over-the-counter drugs that go through rigorous FDA approval processes, herbal supplements are regulated differently in the United States. The FDA classifies them as dietary supplements, which means they don't require the same level of testing and approval before they reach store shelves.

The key difference lies in how these products are regulated and what claims makers can make about them. Medications must prove they are safe and effective for specific conditions before the FDA approves them for sale. Herbal supplements, on the other hand, are assumed to be safe unless the FDA has evidence otherwise. Manufacturers can make certain structure-function claims about supplements, such as "supports heart health," but they cannot claim that a supplement treats, prevents, cures, or mitigates a disease without FDA approval.

Many people use herbal supplements because they believe they are "natural" and therefore safer than conventional medications. However, natural does not automatically mean safe. Poison ivy is natural, but it causes serious skin reactions. Some herbal supplements can cause side effects, interact with medications, or be harmful at high doses. The National Institutes of Health reports that about 20 percent of people taking prescription medications also use herbal supplements, sometimes without telling their doctors.

Understanding this distinction is important because it affects how you should approach using these products. Just because something is available without a prescription does not mean it requires no caution. Practical takeaway: Before using any herbal supplement, research what it contains, how it works in the body, and whether it may interact with medications or conditions you have. Always discuss herbal supplement use with your doctor or pharmacist.

Common Herbal Supplements and What Research Shows

Several herbal supplements are widely used and have been studied by researchers. Echinacea, made from the purple coneflower plant, is used by many people to support immune function. Some studies suggest it may slightly reduce the duration or severity of cold symptoms if taken early, though results are mixed. The University of Wisconsin School of Medicine and Public Health notes that while echinacea appears relatively safe, it may not prevent colds from occurring in the first place.

Ginger comes from the root of the ginger plant and has been used for thousands of years in traditional medicine. Research indicates ginger may help with nausea, including nausea from pregnancy and chemotherapy. A 2016 review in the journal Nutrients found that ginger was more effective than placebo for reducing nausea in some situations. People commonly use ginger as a tea, in capsule form, or as a food seasoning.

St. John's Wort is an herb used by some people to support mood. However, this supplement has significant interactions with many medications, including birth control pills, blood thinners, and antidepressants. The National Center for Complementary and Integrative Health warns that St. John's Wort can reduce the effectiveness of certain medications or increase side effects.

Turmeric, which contains curcumin, is used for various purposes. Some research suggests curcumin may have anti-inflammatory properties, though how well the body absorbs curcumin from turmeric supplements varies widely. Studies on curcumin's effects on joint health and other conditions continue, but results remain mixed.

Garlic, commonly used as a supplement, contains compounds that some research suggests may support cardiovascular health. However, garlic supplements can interact with blood-thinning medications and may increase bleeding risk if combined with these drugs.

Practical takeaway: Research-based information about specific supplements is available from the National Institutes of Health's MedlinePlus website and the National Center for Complementary and Integrative Health. These sources describe what research shows about individual supplements, including both potential uses and known concerns.

Potential Side Effects and Safety Concerns

While many people view herbal supplements as safe because they are natural, side effects do occur. Some supplements cause mild side effects like headaches, digestive upset, or dizziness. Others can cause more serious problems, especially at high doses or when combined with other substances.

Liver damage is a concern with certain supplements. Kava, an herb from the South Pacific, has been linked to liver injury in some users. The FDA has issued warnings about kava, and it is banned in several countries. Comfrey, another herb, contains compounds called pyrrolizidine alkaloids that can damage the liver and kidneys with long-term use.

Allergic reactions are another concern. People allergic to plants in the daisy family may react to echinacea and related herbs. Some people experience allergic reactions to bee pollen supplements. Reactions can range from mild itching to severe anaphylaxis, which is a life-threatening emergency.

Pregnancy and nursing present special considerations. Some supplements are unsafe during pregnancy because they may increase miscarriage risk or cause birth defects. Pregnant women should inform their doctors about any supplements they are taking. Certain supplements can pass into breast milk and affect nursing infants.

The purity and quality of supplements can vary significantly. A 2013 study published in Biology Letters examined 44 herbal supplements and found that about one-third contained ingredients not listed on the label. Some contained fillers or allergens that could cause problems for people with sensitivities. This variation occurs because herbal supplements are not as strictly regulated as medications.

Practical takeaway: Keep a list of all supplements you take and share it with your doctor and pharmacist. Report any unusual symptoms you experience after starting a supplement. If you are pregnant, nursing, have a serious health condition, or take medications, consult your healthcare provider before using any new supplement.

How Herbal Supplements Interact With Medications

One of the most serious concerns with herbal supplements is their potential to interact with prescription and over-the-counter medications. These interactions can reduce how well a medication works, increase side effects, or cause entirely new problems. Many people do not realize that a supplement they are taking could be causing problems with their medications.

St. John's Wort is a well-known example of a supplement with significant interactions. It reduces the effectiveness of oral contraceptives, meaning women taking birth control pills and St. John's Wort have higher pregnancy risk. It also interacts with antidepressants, blood thinners, and medications for heart disease and cancer. The interaction works by speeding up how the body breaks down these medications, making them less effective.

Ginkgo biloba, used to support memory and circulation, can increase bleeding risk when combined with blood-thinning medications like warfarin or aspirin. People scheduled for surgery should stop taking ginkgo at least two weeks before their procedure because of this bleeding risk.

Garlic supplements also increase bleeding risk when combined with blood thinners. Ginger, while generally considered safe, may increase bleeding risk at high doses, especially when combined with anticoagulant medications.

Supplements containing caffeine, such as guarana or yerba mate, can increase side effects when combined with stimulant medications or excessive caffeine from other sources. This can cause heart palpitations, high blood pressure, or anxiety.

The American Association of Retired Persons reports that about 38 percent of people over age 50 take herbal supplements, and many take them without informing their doctors. This creates a significant risk for unrecognized drug-supplement interactions. Your pharmacist can check your medication list against any supplements you plan to take and alert you to potential interactions.

Practical takeaway: Before starting any supplement, ask your pharmacist or doctor whether it may interact with your current medications. Do not stop taking prescribed medications to use supplements instead without discussing this with your healthcare provider first. Bring a complete list of all supplements and medications to every doctor appointment.

Understanding Labels, Quality, and Choosing Supplements Wisely

Reading and understanding supplement labels is a critical skill for anyone considering these products. Unlike medications, which must list specific information in a standardized format, supplement labels vary more in what they display and how they present information.

Supplement labels must include the supplement facts panel, which lists the active ingredients and their amounts. However, determining what the "right" amount is can be challenging because supplements do not have recommended doses the way medications do