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Adaptogen Research & Evidence

How much human research exists on adaptogens, what NIH and a European regulator say about it, where reviews disagree, and how to read an adaptogen study without being misled.

Content last updated . This page has not been medically reviewed.

Safety first. Natural products can cause side effects and interact with medicines. Read who should be careful, by situation before you use anything on this page.

Information only. This page describes research. It does not say that any adaptogen treats a condition, and it is not a reason to start or stop anything. Several herbs sold as adaptogens have documented cautions with medicines, pregnancy, surgery, the thyroid and the liver. Ask a pharmacist or clinician first, and see how medicine interactions work.

Quick answer
"Adaptogen" is a label, not a proven category. The European Medicines Agency's herbal medicines committee wrote in 2008 that the term is not accepted in the pharmacological and clinical language commonly used in the EU, and that it is not appropriate for a marketing authorisation. [1] The same paper said the available data were enough to justify further research into the concept. [1]

So the honest answer to "do adaptogens work?" is: it depends on the plant, the extract, the outcome and the person, and for most of them the evidence is limited. Evidence label: promising but limited for a few preparations, insufficient evidence for most.

Where the term comes from

Sources disagree on the exact date and wording, which is worth knowing before trusting any single "history" you read online. One review says the word was first proposed in 1940 by N. Lazarev of the USSR. [2] The EMA paper dates Lazarev's use of the term to 1947, [1] and a 2021 review also says 1947. [3] See the history of the concept for the full picture. The term is also used loosely: one 2023 review of "adaptogens" and depression found St. John's wort to be the most studied "adaptogen" in its set, which shows how wide the label can stretch. [4]

Evidence snapshot

The table counts records in PubMed (a research database run by the US National Library of Medicine). A count shows how much has been published. It does not show whether an ingredient works, and it is not a quality measure.
IngredientRecords tagged as randomized controlled trialsRecords tagged as any clinical trialAll PubMed records that mention itCheck it yourself
Ashwagandha61792,258PubMed search
Rhodiola60691,482PubMed search
Asian ginseng1291545,176PubMed search
American ginseng4348936PubMed search
Eleuthero2430541PubMed search
Holy basil (tulsi)17211,073PubMed search
Schisandra14191,678PubMed search
Amla29361,200PubMed search
Astragalus911165,314PubMed search
Shatavari913300PubMed search
Maca1415703PubMed search
Licorice root1221736,381PubMed search

Counted 2026-10-22 using NCBI E-utilities. Counts include studies of extracts, blends and non-health topics, and a trial can find no effect. A higher count means more human research has been indexed, not that something works.

How to read adaptogen studies

  • Who was studied? Small groups, narrow populations or healthy volunteers limit what you can conclude. A 2026 review notes many trials have small samples and short durations. [12]
  • Which product? Extract composition and standardization vary a lot, so a result for one extract does not apply to another product or to a plain powder. [12]
  • How long? NCCIH notes most Asian ginseng trials lasted under 3 months. [5]
  • What was measured? Questionnaires about stress or fatigue are subjective and can respond to placebo.
  • Who paid, and has anyone repeated it? Check the funding and conflict statements, and whether independent groups found the same thing. [10]
  • Animals or people? Most mechanism work is in cells and animals. One 2022 review of adaptogens had a focus on animal studies. [13] See human vs animal research.

Where to go next

In this section

  • Research by Wellness Goal

Dashed labels are guides in preparation. We link a page only when it has real, sourced content.

Frequently asked questions

Are adaptogens real?

The plants are real and many have been studied. The category is contested: the European Medicines Agency's herbal committee wrote in 2008 that the term is not accepted in the pharmacological and clinical terminology commonly used in the EU. [1] Whether a given plant helps a given person is a separate question answered one ingredient at a time.

Do adaptogens work?

For ashwagandha, NCCIH says some preparations may be effective for insomnia and stress, while evidence for anxiety is unclear. [6] For rhodiola and astragalus it says there is not enough reliable evidence. [7][8] A meta-analysis of 12 ashwagandha trials with 1,002 participants rated the certainty of the evidence as low. [15]

How much human research exists?

The PubMed snapshot above shows the counts per ingredient. For quality, reviews describe many trials as small and short with varied extracts. [12] Rhodiola reviews, for example, disagree on how good the trials are. [10][11]

Is research on one adaptogen true for the others?

No. Results belong to the specific plant, plant part, extract and population studied. Panax ginseng (Asian ginseng), American ginseng and eleuthero (Eleutherococcus senticosus, also called Acanthopanax senticosus) are different plants. [16]

Where can I find the evidence for one herb?

Use research by ingredient for a table, or the herb's own guide, such as ashwagandha or rhodiola.

More details: evidence, limits and cautions

The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.

What NIH says about the evidence
NIH's National Center for Complementary and Integrative Health (NCCIH) summarizes several adaptogen herbs. NCCIH itself describes Asian ginseng as "used ... as an adaptogen" in traditional Chinese medicine, which is a statement about use, not proof. [5] These are the NCCIH summaries as read on 2026-10-23.
Ingredient (plant part studied)NCCIH summaryEvidence label
Ashwagandha (Withania somnifera; root, leaf or both)Some preparations may be effective for insomnia and stress; evidence unclear for anxiety; many studies small and using varied preparations. [6]Promising but limited (stress, sleep); mixed (anxiety)
Asian ginseng (Panax ginseng; root) [5]Possible small benefit for general fatigue, but not all research agrees; most research shows no athletic benefit; most trials small and under 3 months. [5]Mixed
Rhodiola (Rhodiola rosea; root)Not enough reliable evidence for any health-related purpose; most human research low to moderate quality. [7]Insufficient evidence
Astragalus (Astragalus membranaceus; root) [8]Not enough reliable evidence for any health condition. [8]Insufficient evidence
Licorice (Glycyrrhiza glabra, G. uralensis, G. inflata; root) [9]Not enough high-quality evidence for any health condition. [9]Insufficient evidence

NCCIH calls astragalus an adaptogen, theorized to stimulate resistance to stress. [8] The licorice page does not use the word in the part we read, so licorice is listed here because it is often sold with adaptogens, not because NCCIH classes it that way.

Why two reviews of one herb can disagree
Rhodiola shows how. A 2011 systematic review found 11 placebo-controlled trials and judged the quality of most as moderate or good, but noted a lack of independent replications. [10] A 2012 review of rhodiola for fatigue found 11 studies and judged every one as high risk of bias or having reporting flaws, calling the research contradictory. [11] Different questions, different quality tools and different judgments give different headlines. The details are on human clinical studies and research by ingredient.
Gaps in the research
Long-term safety is not well established: NCCIH says there is not enough information to reach conclusions about ashwagandha's long-term safety. [6] Medicine interactions are also under-studied. A 2023 chart review of adverse event reports linked several adaptogen herbs with antidepressant side effects and advised clinicians to monitor. [14] Head-to-head comparisons are rare. Proper evidence not found in the sources we read for a trial comparing two adaptogens directly (we searched NCCIH and PubMed for systematic reviews and trials of adaptogens).
Safety points from the sources
NCCIH says there have been a number of cases linking liver injury to ashwagandha supplements, although this is rare, and that ashwagandha should be avoided in pregnancy and not used while breastfeeding. [6] It is not recommended before surgery or with autoimmune or thyroid disorders, and may interact with diabetes and blood pressure medicines. [6] NCCIH reports interactions between rhodiola and losartan, and little is known about rhodiola in pregnancy or breastfeeding. [7] Astragalus might worsen autoimmune disease symptoms. [8] Licorice contains glycyrrhizin, which can cause serious adverse effects such as irregular heartbeat. [9] Tell your surgical team about every supplement, and ask the prescriber or pharmacist before combining any with a medicine. Product quality varies too; see quality testing and certifications.
References
  1. 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.
  2. Chin Med 2018. A preliminary review of studies on adaptogens: comparison of their bioactivity in TCM with that of ginseng-like herbs used worldwide. Review article. Read 2026-10-23.
  3. Nutrients 2021. Plant Adaptogens - History and Future Perspectives. Review, full text read 2026-10-23.
  4. Int J Environ Res Public Health 2023. Adaptogens on Depression-Related Outcomes: A Systematic Integrative Review and Rationale of Synergism with Physical Activity. Abstract read 2026-10-23.
  5. National Center for Complementary and Integrative Health (NIH). Asian Ginseng: Usefulness and Safety. Read 2026-10-23.
  6. National Center for Complementary and Integrative Health (NIH). Ashwagandha: Usefulness and Safety. Read 2026-10-23.
  7. National Center for Complementary and Integrative Health (NIH). Rhodiola: Usefulness and Safety. Read 2026-10-23.
  8. National Center for Complementary and Integrative Health (NIH). Astragalus: Usefulness and Safety. Read 2026-10-23.
  9. National Center for Complementary and Integrative Health (NIH). Licorice Root: Usefulness and Safety. Read 2026-10-23.
  10. Phytomedicine 2011. The effectiveness and efficacy of Rhodiola rosea L.: a systematic review of randomized clinical trials. Systematic review, abstract read 2026-10-23.
  11. BMC Complement Altern Med 2012. Rhodiola rosea for physical and mental fatigue: a systematic review. Systematic review, abstract read 2026-10-23.
  12. Nutrients 2026. System-Level, Molecular and Cellular Mechanisms of Selected Plant Adaptogens - A Review. Review, full text read 2026-10-23.
  13. Phytomedicine 2022. A literature review of the studies concerning selected plant-derived adaptogens and their general function in body with a focus on animal studies. Abstract read 2026-10-23.
  14. Front Pharmacol 2023. Harder, better, faster, stronger? Retrospective chart review of adverse events of interactions between adaptogens and antidepressant drugs. Abstract read 2026-10-23.
  15. Phytother Res 2022. Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Abstract read 2026-10-23.
  16. GBIF Secretariat. GBIF Backbone Taxonomy, species match service, queried for each plant name used on this page. Read 2026-10-23.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.