Adaptogens: What They Are, What The Evidence Shows And Which Ones Work

ByJustin Updated on

Adaptogens are herbs and mushrooms said to help the body resist and recover from physical and mental stress, such as rhodiola, ashwagandha, ginseng and eleuthero. The idea comes from Soviet-era stress research, and it is still not an accepted medical category: European regulators have said the term is not appropriate for medicine claims. Among adaptogenic herbs, ashwagandha and rhodiola have the most human research, with modest benefits for stress, sleep and fatigue, while most others rest on thin evidence.[1],[2],[3],[6]

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Key Takeaways

  • An adaptogen is a substance claimed to raise “non-specific resistance” to stress. The term grew out of Soviet research in the mid-20th century.[1]
  • The European Medicines Agency does not accept “adaptogen” as a pharmacological or clinical term.[2]
  • Ashwagandha has the strongest evidence of the group for stress, anxiety and sleep, though the overall certainty is still rated low.[6],[7]
  • Rhodiola trials for fatigue are mixed and often flawed; NCCIH says there is not enough reliable evidence for any use.[3],[5]
  • Evidence for eleuthero, schisandra, reishi and cordyceps in humans is limited.[12],[13],[14],[15]
  • Adaptogens are not risk-free: ashwagandha has been linked to rare liver injury, and several herbs interact with common drugs.[8],[13],[14]

What Are Adaptogens?

The term “adaptogen” was introduced by the toxicologist Lazarev in the Soviet Union, building on Hans Selye’s theory of stress. Researchers Brekhman and Dardimov later described adaptogens as substances that are largely harmless and that increase the body’s resistance to a broad range of stressors in a non-specific way.[1] Much of the early work was done on eleuthero (Siberian ginseng), rhodiola and schisandra.[1]

Supporters of the concept propose that adaptogens act on the body’s stress system, the hypothalamic-pituitary-adrenal (HPA) axis, and on cellular stress proteins. One influential theory describes them as mild “stress mimetics” that prime cells to handle bigger stressors later, similar to how exercise trains the body.[1] Most of that mechanism research comes from cell and animal studies.[1]

Is “Adaptogen” A Medical Term?

No. In a 2008 reflection paper, the European Medicines Agency’s herbal medicines committee concluded that “adaptogen” is not a pharmacological or clinical term in common use and is not appropriate for a medicine’s marketing authorization, because clinical data were not sufficient to show efficacy for a clearly defined condition.[2] Even a sympathetic review of the field notes that the label is often applied to plants that do not meet its own definition.[1]

That matters for shoppers. “Adaptogenic” on a label is a marketing description, not a sign that a product has been tested for stress. Judge each herb on its own evidence.

List Of Adaptogens And Their Benefits: Evidence By Herb

Adaptogen Main Claimed Use Human Evidence Key Safety Notes
Ashwagandha Stress, anxiety, sleep Moderate quantity, low certainty[6],[7] Rare liver injury; avoid in pregnancy and thyroid disease[8]
Rhodiola rosea Fatigue, mental performance under stress Limited and mixed[3],[5] Dizziness, headache, insomnia; possibly safe up to 12 weeks[5]
Panax (Asian) ginseng Energy, cognition, fatigue Limited; small effect on fatigue[10],[11] Insomnia; may affect blood sugar and clotting[11]
Eleuthero (Siberian ginseng) Stamina, stress Very limited[12] Can raise digoxin levels and skew digoxin tests[12]
Schisandra Stress, fatigue, liver Very limited[13] May affect drug-metabolizing enzymes; raises tacrolimus levels[13]
Reishi mushroom Immunity, stamina, calm Limited, mixed[14] Case reports of liver injury; may increase bleeding risk[14]
Cordyceps Energy, exercise Very limited; mixed exercise trials[15] May add to blood sugar-lowering and bleeding risk[15]

Ashwagandha (Evidence: Moderate For Stress, Low Certainty)

Ashwagandha (Withania somnifera) is the most-studied adaptogen in modern trials.

  • Stress and anxiety: a 2022 meta-analysis of 12 randomized trials with 1,002 adults found that ashwagandha reduced anxiety and stress scores compared with placebo. The trials were highly inconsistent, and the authors rated the certainty of evidence as low. Stress benefits appeared at 300–600 mg a day.[6]
  • Sleep: a 2021 meta-analysis of five trials with 400 adults found a small but significant improvement in overall sleep, with larger effects in people with insomnia, at 600 mg a day or more, and with eight weeks or more of use.[7]

The NIH’s NCCIH summarizes it this way: some ashwagandha preparations may help with stress and insomnia, while evidence on anxiety is unclear.[8] For more detail, see our ashwagandha guide.

Rhodiola Rosea (Evidence: Limited)

Rhodiola is the classic “anti-fatigue” adaptogen.

  • A 2012 systematic review of 11 trials found that two of six trials reported benefits for physical fatigue and three of five for mental fatigue, but every study had a high or unclear risk of bias. The authors called the evidence contradictory.[3]
  • In one of the better trials, 60 adults with stress-related fatigue took 576 mg a day of the SHR-5 extract or placebo for 28 days. Both groups improved, but rhodiola did better on a burnout scale and some attention measures and blunted the morning cortisol response.[4]

NCCIH concludes there is not enough reliable evidence that rhodiola is useful for any health purpose, noting that most human research is low to moderate quality.[5] If you are deciding between the two most popular options, see ashwagandha vs. rhodiola.

Panax Ginseng (Evidence: Limited)

A Cochrane review found nine randomized trials of ginseng for cognition, but only five had usable data, and the results could not be pooled. The authors found a lack of convincing evidence that ginseng enhances cognition in healthy people.[10] NCCIH notes small studies suggesting improved attention and reaction time in middle-aged adults, and a 2023 review of 19 studies suggesting ginseng alone may have a small benefit for general fatigue.[11] Our Panax ginseng page covers it in depth.

Eleuthero (Siberian Ginseng) (Evidence: Very Limited)

Eleuthero (Eleutherococcus senticosus) is not a true ginseng, though it was central to early Soviet adaptogen research.[1],[12] Memorial Sloan Kettering’s herb database describes human studies as “quite limited,” with its fatigue findings coming from animal research.[12]

Schisandra (Evidence: Very Limited)

Schisandra berry is a traditional adaptogen in Chinese and Russian medicine, but human studies are limited. The one cognition trial cited by Memorial Sloan Kettering tested a combination formula, so the result cannot be attributed to schisandra alone.[13]

What Are Adaptogenic Mushrooms?

Adaptogenic mushroom supplements usually contain reishi, cordyceps, chaga or lion’s mane. These are traditional medicinal mushrooms that marketers have grouped under the adaptogen label. Human evidence for stress or energy is thin:

  • Reishi (Ganoderma lucidum) has small clinical studies suggesting possible effects on urinary symptoms, blood lipids and anxiety, but randomized trials did not support it for cardiovascular risk factors. Case reports link powdered reishi to liver injury, including one death.[14]
  • Cordyceps is sold for energy and stamina, but exercise trials in healthy people were mixed, and one found that a cordyceps product did not improve endurance performance.[15]

Lion’s mane is usually marketed for cognition rather than stress; it has its own small body of research, which we cover on our lion’s mane page.

Adaptogens Vs. Nootropics: What Is The Difference?

The two categories overlap but are not the same:

  • Nootropics are substances taken to support cognitive functions such as memory, focus or mental energy. See what are nootropics for a full explanation.
  • Adaptogens are taken to support the body’s response to stress, which may indirectly affect mental performance when you are tired or under pressure.

Rhodiola is the clearest crossover: its best-known trial measured both fatigue and attention under stress.[4] Many nootropic stacks include an adaptogen for that reason. Adaptogens are generally not expected to boost cognition in rested, unstressed people, and the ginseng evidence in healthy adults reflects that.[10]

Adaptogens For Anxiety, Stress And Sleep

If your main goal is stress relief, calmer days or better sleep, ashwagandha has the most supporting data among adaptogens, with low-certainty evidence for stress and anxiety and small benefits for sleep.[6],[7] Rhodiola is used more for stress-related fatigue than for relaxation.[4] Ginseng is not a good choice for sleep, since insomnia is its most common side effect.[11]

Non-adaptogen options such as L-theanine and magnesium are also commonly used for calm and sleep and are worth comparing. Persistent anxiety or insomnia deserves a conversation with a clinician, since effective non-supplement treatments exist.

Adaptogens For Energy

Adaptogen herbs for energy, mainly rhodiola, ginseng, eleuthero and cordyceps, are not stimulants like caffeine. The proposed benefit is less fatigue under stress over weeks, not a quick lift. The best evidence is for ginseng’s possible small effect on general fatigue and rhodiola’s mixed results in stress-related fatigue.[3],[4],[11] Cordyceps and eleuthero have little human evidence for energy.[12],[15]

Adaptogens And Weight Loss: A Skeptical Look

“Adaptogen weight loss” products usually claim to lower cortisol and curb stress eating. The evidence for that is very thin. The main trial is a 2017 study of 52 adults under chronic stress who took 300 mg of ashwagandha root extract or placebo twice daily for eight weeks. The authors reported improvements in stress, food cravings, cortisol, body weight and BMI, but the abstract does not report how much weight people lost.[9]

One small, eight-week trial in a specific group of stressed adults is not evidence that adaptogens cause meaningful weight loss. No adaptogen has been shown to replace diet, activity or medical weight-loss treatment, and we would be wary of any product that leans on this claim.

Adaptogens For Hormone Balance

“Hormone balancing adaptogens” is a marketing phrase, not a recognized treatment category. Some adaptogens do affect hormones, which is a reason for caution rather than enthusiasm. NCCIH advises that people with thyroid disorders should avoid ashwagandha and notes that it may raise testosterone, so people with hormone-sensitive prostate cancer should avoid it.[8] If you suspect a hormone problem, get tested rather than self-treating.

Are Adaptogens Safe?

“Natural” does not mean risk-free. Key safety points by herb:

  • Ashwagandha: may be safe for up to three months, but long-term safety is unknown. A number of liver injury cases have been reported. Avoid it during pregnancy and breastfeeding, with thyroid or autoimmune disease, and before surgery. It may interact with diabetes, blood pressure, immunosuppressant, sedative and anticonvulsant medicines.[8]
  • Rhodiola: possibly safe for up to 12 weeks; side effects include dizziness, headache and insomnia, and an interaction with the blood pressure drug losartan has been reported.[5]
  • Asian ginseng: appears safe short term; insomnia is the most common side effect, and it may affect blood sugar and clotting.[11]
  • Eleuthero: can raise digoxin levels and produce falsely high digoxin test results.[12]
  • Schisandra: may change how the liver processes some drugs and has raised tacrolimus levels in transplant patients.[13]
  • Reishi: case reports of liver injury; may increase bleeding risk with blood thinners and may not be safe with immunosuppressants.[14]
  • Cordyceps: may add to the effect of blood sugar-lowering drugs and anticoagulants.[15]

For a wider look at supplement risks, read our guide to nootropic side effects.

How To Choose The Best Adaptogen Supplements

  • Pick the herb for the goal. Ashwagandha for stress and sleep; rhodiola for stress-related fatigue.
  • Match the studied extract and dose. Ashwagandha stress benefits appeared at 300–600 mg a day, and sleep benefits at 600 mg or more.[6],[7] The rhodiola SHR-5 trial used 576 mg a day.[4]
  • Look for standardization (for example, withanolides for ashwagandha, rosavins and salidroside for rhodiola) and third-party testing.
  • Be wary of proprietary “adaptogen blends” that do not disclose individual amounts. They often contain small doses of many herbs.
  • Check your medications first, given the interactions listed above.

Mind Lab Pro: A Small Dose Of Rhodiola In A Broader Stack

Mind Lab Pro includes rhodiola rosea (50 mg, standardized to 3% rosavins and 1% salidroside) alongside L-theanine, citicoline, bacopa and other nootropics. To be clear, 50 mg is far below the 576 mg used in the SHR-5 fatigue trial, so it should not be expected to reproduce those results.[4] We see it as a well-tolerated daily cognitive stack, not a dedicated adaptogen. It does not contain ashwagandha.

Check Mind Lab Pro Price

If you want a single adaptogen at a study-matched dose, Nootropics Depot sells standardized, third-party-tested extracts. Look for their ashwagandha and rhodiola rosea extracts on Amazon, buying only from listings marked “Sold by Nootropics Depot.”

Frequently Asked Questions

What Does Adaptogenic Mean?

Adaptogenic describes a substance claimed to increase the body’s non-specific resistance to stress.[1] It is a traditional and marketing term rather than an accepted medical category.[2]

What Is The Best Adaptogen For Anxiety?

Ashwagandha has the most trial data for stress and anxiety, though a meta-analysis rated the certainty of evidence as low.[6] Anyone with an anxiety disorder should speak with a clinician.

Do Adaptogens Help You Sleep?

Ashwagandha showed a small benefit for sleep in a meta-analysis of five trials, mostly at 600 mg a day or more for eight weeks or longer.[7] Other adaptogens have little sleep data, and ginseng can cause insomnia.[11]

Can Adaptogens Help With Weight Loss?

Not in any reliable way. The main supporting evidence is one small eight-week ashwagandha trial in stressed adults.[9]

Are Adaptogenic Mushrooms Adaptogens?

They are marketed that way, but human evidence for reishi and cordyceps as stress or energy aids is limited.[14],[15]

Can You Take Adaptogens Every Day?

Most trials lasted weeks to a few months. NCCIH describes ashwagandha as possibly safe for up to three months and rhodiola for up to 12 weeks, with less known about longer use.[5],[8]

Can I Take Adaptogens With Nootropics?

Many stacks combine them, such as rhodiola with L-tyrosine or ashwagandha with L-theanine. Start one ingredient at a time and check for drug interactions. Our nootropic stacks guide has more.

Medical disclaimer: This article is for educational purposes only and is not medical advice. Dietary supplements are not evaluated by the FDA to diagnose, treat, cure or prevent any disease. Talk with your doctor or pharmacist before starting a supplement, especially if you are pregnant, nursing, take prescription medication or have a medical condition. Read our full medical disclaimer.

References

  1. Panossian A, Wikman G. Effects of adaptogens on the central nervous system and the molecular mechanisms associated with their stress-protective activity. Pharmaceuticals (Basel). 2010;3(1):188-224. DOI
  2. European Medicines Agency, Committee on Herbal Medicinal Products (HMPC). Reflection paper on the adaptogenic concept. EMEA/HMPC/102655/2007. May 8, 2008. EMA
  3. Ishaque S, Shamseer L, Bukutu C, et al. Rhodiola rosea for physical and mental fatigue: a systematic review. BMC Complement Altern Med. 2012;12:70. DOI
  4. Olsson EM, von Schéele B, Panossian AG. A randomised, double-blind, placebo-controlled, parallel-group study of the standardised extract SHR-5 of the roots of Rhodiola rosea in the treatment of subjects with stress-related fatigue. Planta Med. 2009;75(2):105-112. PubMed
  5. National Center for Complementary and Integrative Health. Rhodiola: Usefulness and Safety. Updated April 2025. NCCIH
  6. Akhgarjand C, Asoudeh F, Bagheri A, et al. Does ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Phytother Res. 2022;36(11):4115-4124. PubMed
  7. Cheah KL, Norhayati MN, Husniati Yaacob L, et al. Effect of ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLoS One. 2021;16(9):e0257843. DOI
  8. National Center for Complementary and Integrative Health. Ashwagandha. Updated March 2023. NCCIH
  9. Choudhary D, Bhattacharyya S, Joshi K. Body weight management in adults under chronic stress through treatment with ashwagandha root extract: a double-blind, randomized, placebo-controlled trial. J Evid Based Complementary Altern Med. 2017;22(1):96-106. PubMed
  10. Geng J, Dong J, Ni H, et al. Ginseng for cognition. Cochrane Database Syst Rev. 2010. doi:10.1002/14651858.CD007769.pub2. Cochrane Library
  11. National Center for Complementary and Integrative Health. Asian Ginseng. Updated February 2025. NCCIH
  12. Memorial Sloan Kettering Cancer Center. Siberian Ginseng (About Herbs database). Updated February 15, 2022. MSK
  13. Memorial Sloan Kettering Cancer Center. Schisandra (About Herbs database). Updated June 3, 2022. MSK
  14. Memorial Sloan Kettering Cancer Center. Reishi Mushroom (About Herbs database). Updated May 5, 2026. MSK
  15. Memorial Sloan Kettering Cancer Center. Cordyceps (About Herbs database). Updated February 10, 2022. MSK

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