7 Adaptogen Herbs for Stress and Anxiety (Ranked by Evidence)

Adaptogens are a class of plants and fungi that help the body maintain homeostasis under stress — modulating the HPA axis, supporting adrenal function, and helping the nervous system respond to stressors without becoming overwhelmed. The term was coined by Soviet pharmacologist Nikolai Lazarev in the 1940s, and the science has grown substantially since. Here are seven evidence-informed adaptogens, ranked by the strength of their clinical evidence for stress and anxiety.

1. — Ashwagandha (Withania somnifera) — Strongest Evidence

Ashwagandha is the most extensively studied adaptogen for stress and anxiety, with the largest body of randomized controlled trial (RCT) evidence in humans. Multiple well-designed trials have found that ashwagandha root extract significantly reduces perceived stress (as measured by validated scales like the Perceived Stress Scale and Depression Anxiety Stress Scales), reduces serum cortisol, improves sleep quality, reduces anxiety, and improves energy and cognitive function under stress. A 2019 study in Medicine found significant reductions in all stress and anxiety measures at both 240 mg and 600 mg daily doses, with no significant adverse effects. The active compounds (withanolides) appear to modulate GABA receptors and reduce the HPA axis stress response. Avoid in autoimmune thyroid disease, pregnancy, and with immunosuppressants. KSM-66 and Sensoril are the most clinically studied proprietary extracts.

2. — Rhodiola Rosea — Strong Evidence, Fast-Acting

Rhodiola rosea is my second-ranked adaptogen, distinguished by notably faster onset of effects compared to ashwagandha (days rather than weeks), making it useful for acute stress periods. A substantial body of RCT evidence supports rhodiola’s effects on fatigue, stress resilience, cognitive performance under stress, and burnout. A 2018 meta-analysis found rhodiola superior to placebo for reducing fatigue, anxiety, and overall stress. It’s particularly effective for what clinicians call ‘stress-induced burnout’ — the depletion state from chronic overload. Rhodiola’s active compounds (rosavins, salidroside) appear to modulate the stress response proteins and have direct effects on serotonin and norepinephrine reuptake. A typical dose is 200–400 mg of standardized extract daily. Avoid in pregnancy; start with lower doses as some people find it slightly stimulating initially.

3. — Holy Basil (Ocimum tenuiflorum / Tulsi) — Good Evidence

Holy basil — known as tulsi in Ayurvedic medicine and regarded as ‘the queen of herbs’ — has a meaningful body of clinical evidence for anxiety and stress reduction. Multiple human RCTs have found tulsi supplementation to reduce anxiety scores, improve stress-related cognitive function, normalize blood sugar, and reduce cortisol. A 2012 study in the Journal of Ayurveda and Integrative Medicine found significant improvements in stress, anxiety, and depression symptoms with 500 mg of tulsi leaf extract twice daily. Tulsi’s active compounds (ursolic acid, eugenol, beta-caryophyllene) have anti-inflammatory, adaptogenic, and COX-2 inhibitory effects. It is also useful for blood sugar regulation — a relevant feature since blood sugar dysregulation drives anxiety. Tulsi is widely available as a tea, which makes it a pleasant daily ritual alongside supplement form.

4. — Eleuthero (Siberian Ginseng) — Moderate Evidence

Eleuthero (Eleutherococcus senticosus) was the original adaptogen studied by Soviet researchers, used to enhance physical and cognitive performance under extreme conditions (cosmonauts, Olympic athletes, military personnel). Clinical evidence supports eleuthero’s effects on physical endurance, cognitive performance under stress, and immune function, with some trials showing reduced fatigue and improved mental performance. It is less robustly studied for anxiety specifically compared to ashwagandha and rhodiola, but is valued for its broad adaptogenic effects particularly for physical stress and immune resilience. Eleuthero is generally milder than other adaptogens and well-tolerated in most people. Doses range from 300–1,200 mg daily of standardized extract. Use with caution in autoimmune conditions and those on blood pressure medications.

5. — Schisandra (Schisandra chinensis) — Moderate Evidence

Schisandra is a berry used in Traditional Chinese Medicine for thousands of years as a ‘five-flavor berry’ (it contains all five basic tastes — sour, sweet, bitter, salty, and pungent). Modern research supports its adaptogenic properties: schisandra improves accuracy and cognitive performance under stress, reduces fatigue, supports liver detoxification pathways (relevant for hormone and toxin clearance), and has antioxidant effects. Several studies have found schisandra to reduce stress-induced cortisol and to improve physical and mental performance in healthcare workers and athletes under sustained stress. It is particularly interesting as a liver-supportive adaptogen — combining stress resilience with hepatoprotective effects makes it particularly useful for people with metabolic stress, liver dysfunction, or medication-related liver burden. Doses of 500–2,000 mg daily of schisandra extract are used.

6. — Maca (Lepidium meyenii) — Emerging Evidence

Maca root, a Peruvian tuber, is best known as an energy and libido enhancer, but has a growing evidence base for mood, stress, and hormonal support. Clinical trials — several conducted in menopausal and perimenopausal women — have found maca to significantly reduce symptoms of depression and anxiety, reduce perimenopausal symptoms, and improve sexual function and energy. Its mechanism is not fully elucidated but appears to involve glucosinolates that modulate estrogen metabolism and a direct hypothalamic effect on hormonal balance. Maca is not a true adaptogen by strict pharmacological definition, but its HPA axis and HPG (reproductive) axis effects are adaptogenic in nature. It is available as a powder (added to smoothies) or capsule. Yellow maca is considered best for energy and mood; black maca for cognitive function; red maca for hormonal/menopausal support.

7. — Reishi (Ganoderma lucidum) — Promising, Less RCT Evidence

Reishi mushroom is revered in traditional East Asian medicine as the ‘mushroom of immortality’ for its broad health effects. Modern research supports reishi’s immune-modulating, anti-inflammatory, and neuroprotective effects. For mental health specifically, reishi has been shown to improve fatigue, depression, and quality of life in people with neurasthenia (stress-exhaustion syndrome) in clinical trials. Its beta-glucans and triterpenes modulate the immune system and have direct effects on neuroinflammation. Reishi also contains a ganoderic acid variant that inhibits cortisol synthesis in vitro. The challenge: clinical trial evidence for stress and anxiety specifically is limited compared to ashwagandha and rhodiola, and most studies are conducted in Asian populations. However, reishi’s safety profile is excellent, and its immune-supporting and anti-inflammatory effects make it a valuable addition to a comprehensive stress-support protocol.

Adaptogens can be genuinely powerful tools for stress and anxiety — but choosing the right one for your specific situation, health history, and medications requires personalized guidance. At drlewis.com, I help patients integrate adaptogenic herbs safely and effectively into their mental health care. Brooklyn and telehealth available.