Focus & Mental Performance
What NCCIH and meta-analyses say about ginseng, ashwagandha and rhodiola for attention, memory and mental performance, and why adaptogens and nootropics are not the same question.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Sudden confusion, or memory and thinking that are getting steadily worse, need a clinician, not a supplement. See memory changes: when to get help. If low mood or hopelessness is part of how you feel, you can call or text 988 in the US. [1]
What the claim is
Adaptogen products are marketed for "focus", "mental clarity" and "cognitive performance". "Adaptogen" is a contested word, and "nootropic" is a marketing term for substances said to improve thinking; see what are nootropics?. This page asks what trials measured about attention, memory and thinking in people, for each plant and group.What research shows
| Ingredient and group studied | What the source found | Evidence label |
|---|---|---|
| Asian ginseng (Panax ginseng), NCCIH summary | A small amount of research suggests it may improve abstract thinking, attention, arithmetic skills and reaction time in middle-aged adults but not young adults; any memory benefit appeared to depend on adding ginkgo. [2] | Promising but limited |
| Ginseng, 2024 meta-analysis of 15 trials (671 people, including healthy people and people with cognitive impairment, schizophrenia or Alzheimer's disease) | An effect on memory was found; no positive effect on overall cognition, attention or executive function. The authors call for higher-quality studies. [3] | Mixed |
| Ashwagandha (Withania somnifera), NCCIH summary | Not enough evidence to determine whether it helps cognitive function. [4] | Insufficient evidence |
| Ashwagandha, 2026 meta-analysis of 20 trials (1,249 adults) | Improved memory, attention and processing speed, and executive function scores; the review also assessed risk of bias and the certainty of evidence. [5] | Promising but limited |
| Ashwagandha, 2020 systematic review of 5 trials | Early signs of improved task performance, attention and reaction time in a mixed group (older adults with mild cognitive impairment, and adults with schizophrenia, schizoaffective or bipolar disorder). [6] | Promising but limited |
| Rhodiola (Rhodiola rosea) | NCCIH: not enough reliable evidence for any health-related purpose. [7] One small crossover trial of 27 resistance-trained adults found better Stroop test scores with a short course of rhodiola, but it tested a narrow group over a short period, and funding is not stated in the abstract we read. [8] | Insufficient evidence |
| Adaptogens compared head-to-head with nootropics | Proper evidence not found. On 2026-10-23 we searched PubMed (title or abstract: adaptogen with nootropic, compared, and trial or randomized) and found one result, a safety study of ashwagandha, not a comparison. | Insufficient evidence |
Findings for one plant, extract or group do not transfer to another. Eleuthero ("Siberian ginseng"), American ginseng and ashwagandha are different plants, so the ginseng row applies to Panax ginseng. A change on a lab test of attention is not the same as better work or study in real life.
Traditional use
NCCIH says Asian ginseng has been used in traditional Chinese medicine as a calming agent. [2] It also notes that rhodiola was traditionally used for work performance and endurance. [7] These are traditional uses and are not evidence of cognitive benefit.What a reader can do
Ask a clinician about sleep, mood, medicines and health conditions that can affect concentration. Everyday approaches are in Focus & Memory and how to improve focus and memory. For botanical and other nootropics see botanical and mushroom nootropics and nootropic evidence by outcome; for mushrooms see mushrooms for focus and memory. Ingredient detail: ginseng for energy, fatigue and cognition.Frequently asked questions
Do adaptogens improve focus?
Evidence is limited and mixed. Ginseng showed an effect on memory in one meta-analysis but not on attention or executive function, and NCCIH finds not enough evidence for ashwagandha and cognitive function. [3][4]
Is ashwagandha good for memory?
A 2026 meta-analysis reported better memory scores, while NCCIH says evidence is not enough to conclude. [5][4] Trials were varied.
Is rhodiola a study aid?
Not enough reliable evidence, according to NCCIH. [7]
Are adaptogens the same as nootropics?
They are different words used by different authors, and we found no source that compares them. A head-to-head comparison: Proper evidence not found.
Is brain fog a reason to see a doctor?
The NHS lists difficulty concentrating during the day because of tiredness as a sign of insomnia, and problems with thinking, memory and concentration among ME/CFS symptoms. [9][10] If it is persistent or sudden, ask a clinician.
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
- Ashwagandha: NCCIH notes drowsiness and stomach upset, rare liver injury, avoidance in pregnancy and breastfeeding, and possible interactions with medicines for diabetes and high blood pressure, immunosuppressants, sedatives, anti-seizure medicines and thyroid hormone medicines. [4]
- Asian ginseng: insomnia is the most common side effect; it might lower blood sugar and interfere with blood clotting. [2]
- Rhodiola: dizziness, headache and insomnia; a losartan interaction has been reported. [7]
- Stimulants: mixing adaptogens with caffeine or other stimulants is covered in adaptogens versus caffeine and stimulants.
- Tell your prescriber or pharmacist about every supplement; see how medicine interactions work.
References
- 988 Suicide & Crisis Lifeline. 988lifeline.org. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Asian Ginseng. Read 2026-10-23.
- Effects of ginseng on cognitive function: a systematic review and meta-analysis. Phytother Res. 2024;38(12):6023-6034. PubMed 39474788. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Ashwagandha: Usefulness and Safety. Read 2026-10-23.
- Effects of Withania somnifera (L.) Dunal (Ashwagandha) on cognitive and physical function in adults: a systematic review and meta-analysis. Front Pharmacol. 2026;17:1799467. PubMed 42199854. Read 2026-10-23.
- A systematic review of the clinical use of Withania somnifera (Ashwagandha) to ameliorate cognitive dysfunction. Phytother Res. 2020;34(3):583-590. PubMed 31742775. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Rhodiola. Read 2026-10-23.
- Koozehchian MS, et al. Dose-response effects of short-term Rhodiola rosea (golden root extract) supplementation on anaerobic exercise performance and cognitive function in resistance-trained athletes. Nutrients. 2025;17(23):3736. PubMed 41374026. Read 2026-10-23.
- NHS (UK). Insomnia. Read 2026-10-23.
- NHS (UK). Tiredness and fatigue. Read 2026-10-23.