Herbal products are preparations made from plants, or specific parts of plants, that people use for health purposes. They include everything from the echinacea capsules in your medicine cabinet to the turmeric powder in a smoothie blend. In the United States alone, consumers spent a record $13.2 billion on herbal dietary supplements in 2024, a 5.4% increase over the previous year. That growth reflects a massive and expanding category of products, but also one that’s regulated very differently from prescription medications.
How Herbal Products Are Classified
The most important thing to understand about herbal products is that most of them are legally classified as dietary supplements, not drugs. Under the Dietary Supplement Health and Education Act of 1994, supplements fall under the umbrella of foods. This means manufacturers can describe how an ingredient affects the body’s structure or function (for example, “supports immune health”), but they cannot claim their product diagnoses, cures, or treats a disease.
A small number of plant-based ingredients have gone through formal drug approval. Cascara, psyllium, and senna, for instance, are included in the over-the-counter drug review and are regulated as drugs when sold for specific medical purposes like relieving constipation. The distinction matters: a drug must prove it works before it reaches the market, while a dietary supplement does not.
Forms and Preparations
Herbal products come in a wide range of physical forms, and the preparation method affects both potency and how you use them.
- Capsules and tablets contain either dried whole-herb powder or a concentrated extract, and are the most common form sold in retail stores.
- Tinctures are liquid preparations made by soaking plant material in alcohol or another solvent. They’re typically taken in small doses with a dropper.
- Teas and decoctions involve steeping leaves, flowers, or roots in hot water. Decoctions use longer boiling times, usually for tougher materials like bark or roots.
- Topical preparations include creams, salves, and oils applied directly to the skin. Capsaicin cream, derived from chili peppers, is a common example used for pain relief.
- Essential oils and gums are by-products of herbal plants and are also considered herbal medicine, though their uses range from aromatherapy to wound care.
Products can be made from the whole plant or from any individual part: leaves, roots, flowers, bark, or seeds. Oils, resins, and other plant secretions count as herbal preparations too.
Whole Herb vs. Standardized Extract
When you shop for herbal supplements, you’ll often see labels that say “whole herb” or “standardized extract,” and the difference is worth knowing. A whole herb product contains the dried plant material with all of its natural compounds intact. A standardized extract, by contrast, guarantees a specific concentration of one or more active compounds, expressed as a percentage on the label. The goal is batch-to-batch consistency so you get the same potency every time.
The tradeoff is that concentrating one compound can reduce others. Some manufacturers use a second approach: they standardize to a marker compound for identity purposes while preserving the full range of the plant’s chemistry. This “full-spectrum” standardization aims to deliver reliable potency without stripping out potentially beneficial components.
Popular Herbal Products and Their Uses
Dozens of herbal products are widely available, but a handful dominate the market. Psyllium, a fiber supplement used for digestive health, was the top seller in mainstream retail for the third year running in 2024, generating nearly $290 million in sales. Turmeric (sold as curcumin supplements) led the natural products channel with $37.1 million in sales.
Beyond those two, the most commonly used herbal supplements in the U.S. include:
- Echinacea: traditionally used for colds, flu, and respiratory infections.
- St. John’s wort: commonly taken for mild-to-moderate depression.
- Ginkgo biloba: used to support memory and cognitive function, particularly in older adults.
- Ginseng: taken to boost energy, enhance mental and physical performance, and support immune function.
- Garlic supplements: primarily used to help manage cholesterol and blood pressure levels.
- Saw palmetto: popular among men for prostate health, particularly for benign prostate enlargement.
- Black cohosh: commonly used for menopausal symptoms, especially hot flashes.
- Hawthorn: used as a supportive treatment for heart-related conditions including high blood pressure and heart failure.
- Feverfew: taken to help prevent migraines and ease menstrual cramps.
It’s worth noting that “commonly used” does not always mean “proven effective.” The strength of scientific evidence varies widely from herb to herb and from one claimed benefit to another.
How They Work in the Body
Plants produce hundreds of chemical compounds as part of their natural defense systems. Three broad families account for most of the activity in herbal products. Alkaloids, of which over 27,000 structures have been identified, tend to interact with the same signaling systems in the brain that many pharmaceutical drugs target. This is why certain plant compounds can affect mood, pain perception, or alertness. Phenolic compounds, including flavonoids and tannins, are less targeted in their action. They interact with a wide range of proteins in the body, which is partly why they show up in research on inflammation, antioxidant activity, and cardiovascular health. Terpenes, the third major group, encompass thousands of structures and contribute to effects ranging from antimicrobial activity to the distinctive scents of herbs like lavender and peppermint.
Herbal products used in traditional medicine tend to be rich in phenolic compounds and terpenes, and typically low in the more potent (and potentially toxic) alkaloids. This is one reason most common herbal supplements have a relatively wide safety margin when used as directed, though “natural” does not automatically mean harmless.
Herb-Drug Interactions
One of the most significant safety concerns with herbal products is how they interact with prescription medications. Some supplements speed up the body’s processing of a drug, making it less effective. Others slow that processing down, causing drug levels to climb higher than intended.
St. John’s wort is the most well-documented example. It accelerates the breakdown of many medications, reducing their effectiveness. This includes certain heart drugs, cholesterol medications, and organ transplant drugs. It can also interact with antidepressants in a different way, raising levels of the brain chemical serotonin to potentially dangerous levels. Concentrated green tea supplements can reduce blood levels of cholesterol-lowering and blood pressure medications. Goldenseal can change how the body handles the diabetes medication metformin.
People taking medications where even small changes in blood levels can cause serious problems, such as blood thinners, heart rhythm drugs, or immunosuppressants, need to be especially careful about adding herbal products. Telling your healthcare provider about every supplement you take is not optional in these situations; it’s essential.
How Herbal Products Are Regulated
Because herbal supplements are classified as foods rather than drugs, they don’t need to prove they’re effective before they’re sold. Manufacturers don’t submit clinical trial data to the FDA before launching a product. They are, however, required to follow Current Good Manufacturing Practice regulations. These rules mandate clean facilities, properly maintained equipment, quality control checks at every stage of production, and systems to ensure the product contains what the label says it contains.
Labeling requirements include a “Supplement Facts” panel listing ingredients and amounts, a statement of identity, and the required disclaimer that the product has not been evaluated by the FDA to diagnose, treat, cure, or prevent any disease. The FDA can take action against products that are adulterated, mislabeled, or make illegal health claims, but this happens after the product is already on the market rather than before.
This regulatory framework means quality can vary between brands. Third-party testing programs exist to verify that a product actually contains what it claims and is free from contaminants, and looking for those verification seals is one of the more practical ways to gauge product reliability.