Glossary of Adaptogen Terms
Plain-language definitions of adaptogen, HPA axis, cortisol, adrenal fatigue, withanolides, ginsenosides, extract ratio, standardization and other terms you meet in adaptogen articles and labels.
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This glossary explains words you will meet in adaptogen articles, research summaries and supplement labels. It describes what the sources say a word means. It does not say that any product works.
A note on the word "adaptogen." It is a contested term. It comes from Soviet-era research, and sources give different years for its first use: one review says 1940 and the European Medicines Agency (EMA) herbal committee paper says 1947. [1][2] The EMA paper, adopted in 2008, states that the term is not accepted in the pharmacological and clinical terminology commonly used in the EU. [2] In 2025, two researchers proposed that adaptogens be formally recognized as a category of natural products, which suggests it is not a settled category. [3] Which plants count as adaptogens is a question to answer from sources, plant by plant. See What are adaptogens? for the longer story.
The core idea
| Term | What the sources say |
|---|---|
| Adaptogen | A substance thought to help the body resist stress. NIH describes adaptogenic herbs this way. [4] The EMA paper lists traits attributed to adaptogens in Soviet research, for example that an adaptogen is "almost non-toxic to the recipient." [2] These are claimed traits, not proven ones. |
| Stress | In the EMA paper, stress is used in the classic sense of a state of threatened homeostasis. [2] In everyday speech it means something wider, so check which meaning a study uses. |
| Homeostasis | The body keeping its inner conditions steady. The EMA paper links the old adaptogen idea to this concept. [2] |
| Stimulant (as the old papers use it) | A substance that causes a temporary rise in work capacity followed by a drop. The EMA paper says adaptogens were reputed to differ from stimulants in this way. [2] NIH nonetheless lists insomnia as the most common side effect of Asian ginseng, so the ideal does not match every plant. [4] |
| Traditional use | How a plant has been used in a named tradition, such as Ayurveda or Chinese medicine. It is not proof of benefit. Example: NIH says ashwagandha has been used as a medicinal plant, especially in traditional Ayurvedic medicine. [5] |
| Clinical evidence | Results from studies in people. NIH describes the ashwagandha trials as often small and using a variety of preparations, so a result for one preparation does not transfer to another. [5] |
Stress, hormones and the body
| Term | What the sources say |
|---|---|
| HPA axis | Short for hypothalamic-pituitary-adrenal axis. One review says adaptogens mainly act by affecting this axis in response to outside stress. [1] That is a proposed mechanism described in a review, not a proven treatment effect in people. |
| Cortisol | NIDDK says cortisol is sometimes called the "stress hormone" because it helps your body respond to stress. [6] A cortisol reading is a lab marker. It is not the same thing as how a person feels or functions. |
| "Adrenal fatigue" | Not a recognized diagnosis. The Endocrine Society says no scientific proof exists to support it as a true medical condition and that no test can detect it. [7] See adrenal fatigue and "adrenal support" claims. |
| Adrenal insufficiency | A real medical condition, different from "adrenal fatigue." NIDDK says its most common symptom is long-lasting fatigue, and that symptoms can first appear during an adrenal crisis. [8] The Endocrine Society calls adrenal crisis a life-threatening condition. [7] Persistent fatigue deserves a clinician's assessment, not a self-made label. [7] |
| Corticosteroid | A class of medicines. NIDDK says the most common cause of adrenal insufficiency overall is suddenly stopping corticosteroids after taking them for a long time. [8] Never stop a prescribed medicine on your own; ask the prescriber. |
Plants, parts and compounds
| Term | What the sources say |
|---|---|
| Scientific name | The Latin genus and species, for example Withania somnifera (ashwagandha). Names in this library were checked against GBIF. [9] Common names can mislead: NIH lists "Indian ginseng" as a common name for ashwagandha, and eleuthero ("Siberian ginseng") is not related to true ginseng. [5][10] |
| Plant part | Root, leaf, fruit and so on. NIH says ashwagandha supplements typically contain root, leaf, or root/leaf extracts, and results for one part do not transfer to another. [5] |
| Withanolides | A group of substances in ashwagandha. [5] |
| Ginsenosides | Substances in Asian ginseng; NIH says those thought most important are called ginsenosides (or panaxosides). [4] |
| Eleutherosides | Substances in eleuthero. Eleutherosides B and E are used to identify Siberian ginseng. [10] |
| Rosavin and salidroside | Substances used as "active markers" for Rhodiola rosea. A 2018 laboratory study found their content in commercial extracts was highly variable. [11] |
| Red ginseng and white ginseng | NIH says both are Asian ginseng prepared in two different ways. [4] |
Labels, extracts and quality
| Term | What the sources say |
|---|---|
| Marker compound | A substance measured to identify a plant or check an extract. For rhodiola, the 2018 study says standardizing the content of markers is necessary for quality control but insufficient for judging whether an extract works. [11] |
| Extract | A concentrated preparation made from a plant. Rhodiola roots and rhizome extracts are the active ingredients in many products sold as adaptogenic. [11] See standardized extracts. |
| Extract ratio (DER) | A figure such as "10:1." A 2022 review explains that plant-to-extract ratios describe the extract yield from a raw material using a given manufacturing process. [12] The same review calls the belief that a higher ratio means a stronger, better extract the most common misconception. [12] It also uses the term "DER genuine" (Drug to Genuine Extract Ratio). [12] |
| Dietary supplement | In the US, a category of product that, per NIH, is not approved by the FDA before sale. [5] Supplements you buy may differ in important ways from the products tested in studies. [13] |
| Structure/function claim | A label statement about the effect of a substance on maintaining the body's normal structure or function. [13] It is not a claim that the product treats a disease. |
Words we use for evidence
These labels are used across the library: established, promising but limited, mixed, insufficient evidence, no good evidence of benefit, evidence of harm, preclinical (cells or animals), traditional use only, and marketing claim. Where we searched and found nothing usable we write "Proper evidence not found" and say where we looked. Animal and cell results are kept apart from human trials.
What this glossary does not cover
It does not list amounts to take, does not rank ingredients, and does not replace advice from a clinician or pharmacist. For the ingredient-by-ingredient view see the evidence and safety table, and for cautions see adaptogen safety.
Frequently asked questions
What is an adaptogen in one sentence?
A substance, usually a plant, that is thought to help the body resist stress; NIH uses this description, but the EMA paper says the term is not accepted in EU pharmacological and clinical terminology. [4][2]
Is "adrenal fatigue" the same as adrenal insufficiency?
No. The Endocrine Society says there is no scientific proof that adrenal fatigue is a true medical condition, while NIDDK describes adrenal insufficiency as a condition with defined symptoms and causes. [7][8]
Does a lower cortisol number mean a supplement works?
Not by itself. Cortisol is a lab marker that helps the body respond to stress, and a change in a marker is different from a change in how a person feels or functions. [6]
What does "standardized" mean on a label?
It generally refers to a measured marker compound. For rhodiola, researchers say marker content is needed for quality control but does not by itself show an extract works. [11]
Does a higher extract ratio mean a stronger product?
Not necessarily. A 2022 review calls that belief the most common misconception about plant-to-extract ratios. [12]
References
- Liao LY, He YF, Li L, et al. A preliminary review of studies on adaptogens: comparison of their bioactivity in TCM with that of ginseng-like herbs used worldwide. Chin Med. 2018. PubMed 30479654, full text read at PMC6240259. Read 2026-10-23.
- European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). Reflection paper on the adaptogenic concept. EMEA/HMPC/102655/2007, adopted 8 May 2008. Read 2026-10-23.
- Panossian A, Lemerond T. Two sides of the same coin for health: adaptogenic botanicals as nutraceuticals for nutrition and pharmaceuticals in medicine. Pharmaceuticals (Basel). 2025. PubMed 41011217. One author is employed by a company that sells herbal products; abstract read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Asian Ginseng: Usefulness and Safety. Last updated February 2025. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Ashwagandha: Usefulness and Safety. Last updated March 2023. Read 2026-10-23.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Cushing's Syndrome. Read 2026-10-23.
- Endocrine Society. Adrenal Fatigue. Patient resource, January 25, 2022. Read 2026-10-23.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH). Symptoms & Causes of Adrenal Insufficiency & Addison's Disease. Read 2026-10-23.
- GBIF Secretariat. GBIF Backbone Taxonomy. Names checked through the species match API on 2026-10-23.
- Drugs and Lactation Database (LactMed). Eleuthero. NICHD, record dated 2024-09-15, read through its PubMed record 2026-10-23.
- Dimpfel W, Schombert L, Panossian AG. Assessing the quality and potential efficacy of commercial extracts of Rhodiola rosea L. Front Pharmacol. 2018. PubMed 29881348. Abstract read 2026-10-23.
- Monagas M, Brendler T, Brinckmann J, et al. Understanding plant to extract ratios in botanical extracts. Front Pharmacol. 2022;13:981978. PMC9561911. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Using Dietary Supplements Wisely. Read 2026-10-23.