Adaptogens for Brain Fog and Low Mood: What Is Known
What trials report for ashwagandha, rhodiola and Asian ginseng on thinking, low mood and anxiety, why brain fog has many causes, and why adaptogens never replace treatment.
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> Thoughts of suicide, or feeling unsafe? In the US, call or text 988 (Suicide & Crisis Lifeline), or call 911 in a life-threatening situation. [1] If sadness, anxiety or foggy thinking last and affect daily life, see a clinician. NIH says depression can be a serious illness. [2] An adaptogen must not replace treatment; ask the prescriber or pharmacist before combining one with an antidepressant or other medicine.
The claim as it is marketed
Adaptogens are sold for "clear thinking," "brain fog," "mood support" and "anxiety relief." This page checks those claims for three plants, and labels each finding as a trial of people with a condition, or of people without one.What "brain fog" is
Cleveland Clinic describes brain fog as a term for a range of symptoms that cause cognitive impairment, affecting thinking, focus, memory and attention. [3] It lists many possible causes, including lack of sleep, mental health conditions such as anxiety or depression, diabetes, hormonal changes like menopause, autoimmune conditions, and stress. [3] It says there is no specific treatment for brain fog itself, and to tell a provider if it disrupts daily activities. [3] Because causes differ, a clinician can help work out which apply. See brain fog: causes and what helps.What research found
| Question | What the source found | Strength of evidence | Population and form |
|---|---|---|---|
| Does Withania somnifera (ashwagandha) help thinking? | A 2026 meta-analysis of 20 studies (1,249 adults) reported improved memory, attention and processing speed, and executive function. [4] NIH (updated 2023) says there is not enough evidence to determine whether it helps cognitive function. [5] | Promising but limited (newer review vs earlier NIH view) | Adults; ashwagandha preparations varied |
| Does ashwagandha help stress, anxiety or depression? | A 2026 review of 22 trials reported improvements in stress, anxiety and depression, and called for well-designed, high-quality trials. [6] NIH: evidence on anxiety is unclear. [5] | Mixed | Adults |
| In people with diagnosed mental disorders? | A review of 14 studies (360 treated, 353 controls; median follow-up 8 weeks) found an anxiety benefit confirmed by a Bayesian analysis, but depression findings were not confirmed. [7] | Promising but limited for anxiety; insufficient for depression | Mostly anxiety disorders |
| Does Rhodiola rosea root extract help mood? | NIH: not enough reliable evidence for any health-related purpose. [2] A 14-day trial without placebo in 80 mildly anxious people reported lower anxiety, stress and depression scores but no cognitive performance difference. [8] | Mixed / insufficient | Mildly anxious adults; no-treatment control |
| Does rhodiola help major depression? | In a 12-week trial (57 people), differences among rhodiola, sertraline and placebo were not significant; sertraline had more adverse events (63.2%) than rhodiola (30.0%) or placebo (16.7%). [9] | Insufficient evidence | Mild to moderate depression; one extract |
| Does Asian ginseng help thinking? | NIH: a small amount of research suggests improvement in attention, arithmetic and reaction time in middle-aged but not young adults. [10] | Promising but limited | Panax ginseng root |
A rhodiola capsule trial in 100 people with depression gave every group sertraline, so it tests rhodiola as an add-on, not as a replacement. [11] We do not suggest combining herbs with antidepressants without the prescriber.
Both ashwagandha reviews report heterogeneity between trials and call for better-designed research. [6][7]
Limits
- Questionnaires measure how people feel and can improve with placebo.
- A trial in people with a diagnosed disorder is not evidence for "brain fog" in people without one.
- Funding is not described in the abstracts we read.
Frequently asked questions
Do adaptogens clear brain fog?
Brain fog has many causes and no specific treatment, per Cleveland Clinic. [3] A 2026 review reported better memory and attention with ashwagandha, while NIH (2023) found insufficient evidence. [4][5]
Can ashwagandha treat depression or anxiety?
A review in people with mental disorders supported an anxiety benefit, not clearly a depression one; trials were small and short. [7]
Does rhodiola work like an antidepressant?
In one 12-week trial, rhodiola did not differ significantly from placebo or sertraline on depression scores. [9]
Can I take an adaptogen with my antidepressant?
Ask the prescriber or pharmacist. NIH says some herbs and medicines interact in harmful ways. [2]
When should I get help?
When low mood, anxiety or foggy thinking persist or disrupt daily life, see a clinician; call or text 988 for thoughts of suicide. [1]
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.
Safety
- Rhodiola: dizziness, headache, insomnia, dry mouth or excess saliva; an interaction with losartan has been reported; little is known in pregnancy or breastfeeding. [2]
- Ashwagandha: drowsiness, stomach upset; rare liver injury cases; avoid in pregnancy and breastfeeding; might interact with medicines for diabetes and high blood pressure, sedatives, anti-seizure medicines, immunosuppressants and thyroid hormone medicines. [5]
- Asian ginseng: insomnia is the most common side effect. [10]
- Links: adaptogens and mental health conditions, adaptogens vs prescription treatments, supplements and antidepressants, focus and mental performance.
References
- Depression (National Institute of Mental Health). Read 2026-10-23.
- Rhodiola: Usefulness and Safety (NCCIH, NIH). Read 2026-10-23.
- Brain Fog: What It Is, Causes, Symptoms & Treatment (Cleveland Clinic; updated 14 May 2024). Read 2026-10-23.
- Effects of Withania somnifera on cognitive and physical function in adults: systematic review and meta-analysis, Front Pharmacol 2026 (PubMed 42199854). Read 2026-10-23.
- Ashwagandha: Usefulness and Safety (NCCIH, NIH; last updated March 2023). Read 2026-10-23.
- Effects of ashwagandha on mental health in adults: systematic review and dose-response meta-analysis, Complement Ther Med 2026 (PubMed 41644067). Read 2026-10-23.
- The effect of Withania somnifera on mental health symptoms in individuals with mental disorders: systematic review and meta-analysis, BJPsych Open 2025 (PubMed 41140145). Read 2026-10-23.
- The Effects of Rhodiola rosea L. Extract on Anxiety, Stress, Cognition and Other Mood Symptoms, Phytother Res 2015 (PubMed 26502953). Read 2026-10-23.
- Rhodiola rosea versus sertraline for major depressive disorder: randomized placebo-controlled trial, Phytomedicine 2015 (PubMed 25837277). Read 2026-10-23.
- Asian Ginseng: Usefulness and Safety (NCCIH, NIH). Read 2026-10-23.
- Antidepressant effects of Rhodiola capsule combined with sertraline for major depressive disorder, J Affect Disord 2020 (PubMed 32090788). Read 2026-10-23.