herbal supplement
Meaning of herbal supplement: Plant products sold under food rules rather than drug rules, which is what makes their strength and contents so variable.
Definition of herbal supplement
A herbal supplement is a product made from a plant or part of a plant and sold to support health rather than to treat a diagnosed disease. It may be a dried leaf, a root, an extract, an oil or a powder, packaged as a capsule, tablet, tea or tincture. In many countries these products are regulated as foods and not as medicines.
How are they regulated?
Medicines must be shown to work and to be acceptably safe before they can be sold, and every batch is manufactured to a fixed strength. Herbal supplements in many countries are treated as a category of food instead. The maker does not have to prove a product works before selling it, and regulators generally act only once a problem surfaces. Labels may make broad claims about supporting a body function but may not claim to treat a named disease. That difference in the rules, rather than anything about plants, explains most of the confusion around these products.
Why does the content vary so much?
| Source of variation | Effect |
|---|---|
| Growing conditions | Soil, weather and harvest time change how much active compound a plant holds |
| Part used | Root, leaf and seed of one plant can differ completely |
| Extraction method | Water and alcohol pull out different compounds |
| Standardization | Some products are adjusted to a set amount of one marker compound, many are not |
Independent testing has repeatedly found products holding less of the named plant than the label states, a different species entirely, or added pharmaceutical ingredients.
Are they safer because they are natural?
Natural says nothing about safety. Plants make powerful chemicals, and several important drugs were isolated from them, including digoxin from foxglove and the forerunner of aspirin from willow bark. The same potency can cause harm. Interaction with prescribed medicines is the commonest problem: St John's wort speeds up the liver enzymes that clear many drugs, weakening their effect, and several plants alter clotting or blood pressure. Because a supplement often goes unmentioned during a consultation, such interactions can be missed. Herbal medicine as a practice differs from buying a product off a shelf, since a practitioner selects and combines preparations deliberately.
How do they differ from other supplements?
A dietary supplement is the wider legal category, covering vitamins, minerals, amino acids and herbs alike. A vitamin or mineral product supplies a substance the body demonstrably needs, in a known amount. A herbal product supplies a mixture of many compounds whose quantities are rarely fixed and whose effects are often incompletely mapped.
Also known as
Used in a sentence
The medication history recorded two herbal supplements that had not previously been mentioned.
Good to know
Herbal supplements are sold under food rules in many countries, so strength and content vary between brands and batches, and several interact with prescribed medicines by changing how quickly the liver clears them.
Word origin
Where “herbal supplement” comes from
Herbal comes from the Latin herba, meaning grass or green plant.