What Are Adaptogens?

"Adaptogen" is a word for certain plants (and, in marketing, some mushrooms) that are said to help the body resist or adapt to stress. It is a useful word for finding information, but it is a contested term, not a medical category. The European Medicines Agency's herbal medicines committee wrote in 2008 that the term is not part of the pharmacological and clinical vocabulary commonly used in the EU. [1] Whether a given plant counts as an adaptogen, and whether it helps a given person, are separate questions that this library answers one ingredient at a time.

Before you start. This is information, not medical advice. Several herbs sold as adaptogens have documented cautions with medicines, pregnancy, surgery, the thyroid and the liver. See How medicine interactions work and ask a pharmacist or clinician before starting one. If stress, low mood or anxiety is affecting your daily life, a clinician can help; in the US you can call or text 988 (Suicide & Crisis Lifeline) at any time.

What the word means

• The original idea (history, not proof). One 2018 review reports that a scientist from the USSR, N. Lazarev, first proposed the term in 1940 while describing Schisandra chinensis and other herbs. [2] The European Medicines Agency's committee on herbal medicines (HMPC) gives the year as 1947 in its 2008 paper, so even the date differs between sources we read. [1]
• The criteria. The 2018 review lists three early criteria: an adaptogen acts non-specifically against many kinds of stress, helps maintain balance in the body, and does not harm normal functions. [2] It then says the Soviet scientist I. Brekhman studied ginseng from about 1950 and that, in a 1969 definition, adaptogens were not supposed to cause side effects such as insomnia, unlike traditional stimulants. [2]
• The EMA description. The HMPC paper describes adaptogens as "reputed" to raise work capacity without a following drop, unlike stimulants. [1] The word "reputed" matters: it describes what was claimed, not what was proven.
• A functional word. The same 2018 review says the term has generally been used as a functional term, and notes that one author sorted adaptogens into primary adaptogens, secondary adaptogens and adaptogen companions. [2] Different writers draw the line in different places.

Which ingredients are called adaptogens

There is no single agreed list. A 2026 review names Withania somnifera (ashwagandha), Panax ginseng (Asian ginseng), Rhodiola rosea, Schisandra chinensis and Eleutherococcus senticosus (eleuthero) as prominent adaptogens. [4] The EMA paper gives some of the same plants as examples. [1] NIH describes Asian ginseng as having been used as an adaptogen and calls astragalus an adaptogen, "theorized" to stimulate resistance to stress. [5][6] Other ingredients in this library are included because people ask about them, not because every source classes them as adaptogens. The A to Z directory lists each one with its scientific name and classification notes.

What the evidence looks like

Laboratory and animal findings are often promising, but a 2026 review says human trials are often limited by small sample sizes, short durations and differences between herbal preparations. [4] NIH summaries are cautious and differ by plant:

The labels in the right-hand column are our plain summary of the NIH wording. Results for one plant part, extract or product do not transfer to another. See Adaptogen research by ingredient and traditional use versus clinical evidence.

Adaptogens, stimulants and similar words

The 1969 criteria said adaptogens should not cause insomnia. [2] Yet NIH lists insomnia as the most common side effect of Asian ginseng. [5] The definition describes an ideal, and not every ingredient fits it. Compare adaptogens with caffeine and other stimulants. "Nootropic" (marketed for thinking performance) and "calming herb" are separate marketing labels that overlap with "adaptogen"; none of the three words tells you whether a product works.

Mushrooms

Reishi, cordyceps, chaga and lion's mane are marketed as adaptogens, but their guides, evidence and safety notes live in the Mushrooms section. See the adaptogen mushroom overview and the reishi guide.

How to read claims about stress, cortisol and "adrenal support"

• Ask what was measured. Cortisol is sometimes called the "stress hormone" because it helps the body respond to stress. [8] A change in a lab number is not the same as feeling or functioning better.
• Be wary of "balances hormones" or "heals adrenals". The Endocrine Society says no scientific proof supports "adrenal fatigue" as a true medical condition. [9] See Adrenal fatigue and adrenal support claims.
• Ask who, what and how long. Who took part, which plant part and extract, for how long, against what comparison, and who paid for the study.
• Check the safety page for the specific ingredient before using it: adaptogen safety essentials and quality and labels.

Where to go next in this library

• Single herbs: ashwagandha, rhodiola, Asian ginseng and the directory.
• Goals: stress, anxiety and resilience, energy and fatigue, sleep.
• Products and quality: supplement forms, reading labels.
• Safety: medicine interactions, pregnancy and breastfeeding, before surgery.
• Background: history of the concept, glossary, comparisons.
• Everyday stress advice without supplements: how to relieve stress.