"Ashwagandha gives the strength of a horse and the vitality of youth." — Charaka Samhita, 6,000-year-old Ayurvedic text
Ashwagandha (Withania somnifera) has been used in Ayurvedic medicine for over 3,000 years. In the past decade it has become one of the most studied adaptogens. For Withania somnifera the EFSA has not authorised a health claim, so the findings below describe what research observes, not a promised effect.
What Clinical Studies Examine
The table below summarises what individual studies have measured on the plant. These are isolated research observations, not established or promised effects, and they should not be read as an outcome you can expect from taking the product.
| Endpoint studied | What individual studies measured | Source (single study) |
|---|---|---|
| Cortisol | Some studies recorded differences in measured cortisol vs. placebo; not a confirmed effect | Chandrasekhar et al. (2012) |
| Sleep | Some participants subjectively reported sleeping better | Langade et al. (2019) |
| Testosterone | Individual studies noted differences in measured hormone values | Lopresti et al. (2019) |
| Muscle strength | One training study measured strength differences vs. placebo | Wankhede et al. (2015) |
| Stress/tension | Some studies recorded lower scores on stress questionnaires | Chandrasekhar et al. (2012) |
1. Ashwagandha and Cortisol — What Research Examines
Cortisol is a hormone the body releases under stress. In a randomised study (Chandrasekhar et al., 2012), researchers measured differences in serum cortisol between an ashwagandha group and placebo after 60 days. This is a single research finding, not a confirmed or promised effect, and no health claim for ashwagandha is authorised in the EU. The plant has long been used in Ayurvedic tradition as a tonic during periods of stress.
2. Ashwagandha and Sleep — What Research Examines
The Latin name "somnifera" literally means "sleep-bringing." In a study by Langade et al. (2019), some participants subjectively reported sleeping better — a single research observation rather than a proven effect. In Ayurvedic tradition the root has long been valued as a calming tonic, but no health claim for it is authorised in the EU.
3. Ashwagandha and Testosterone — What Research Examines
In a study by Lopresti et al. (2019), researchers measured differences in testosterone and DHEA-S values between an ashwagandha group and placebo after 8 weeks. This is an isolated study result, not a promised effect, and no such health claim is authorised in the EU. In Ayurvedic tradition, ashwagandha and shilajit are often combined.
KSM-66 vs Sensoril vs Regular Extract
| Property | KSM-66 | Sensoril | Regular Extract |
|---|---|---|---|
| Withanolides | 5% | 10%+ | 1.5–2.5% |
| Plant part | Root only | Root + leaves | Whole plant |
| Clinical studies | 24+ studies | 12+ studies | Few or none |
| Focus | Energy, sports, testosterone | Sleep, anxiety, cortisol | Unpredictable |
Doses Used in Studies and Tradition
The amounts below are the doses used in research and traditional practice, not a recommendation to treat any condition or a promise of any outcome. Talk to a doctor before starting a supplement, especially if you take medication.
| Context | Dose used | When | Note |
|---|---|---|---|
| General use in studies | 300–600 mg/day | Morning or evening | Often split into 2 doses |
| Evening use (Ayurvedic tradition) | 300 mg | 1h before bedtime | Sometimes taken with magnesium |
| Doses in male-health studies | 600 mg/day | Morning on empty stomach | Traditionally paired with shilajit |
| Doses in sports studies | 600 mg/day | 1h before training | Studied alongside protein and creatine |
Power Stack: Ashwagandha + Shilajit
This combination is popular in Ayurvedic tradition. Studies examine ashwagandha in connection with cortisol and testosterone, while shilajit is researched for the role of fulvic acid in nutrient transport. The evidence is not uniform, and no health claim is authorised for either.
Who Should NOT Take Ashwagandha?
- Pregnant and nursing women
- People with autoimmune diseases (Hashimoto's, lupus, MS)
- People taking thyroid medications
- People before surgery – stop 2 weeks beforehand
FAQ
How quickly does ashwagandha work?
Can I take ashwagandha and shilajit together?
Is ashwagandha safe for long-term use?
Sources
- Veronese N, Pizzol D, Smith L, Soysal P, Solmi M, Scarsi M, Correll CU, Koyanagi A, Capobianco L, Barbagallo M, Vancampfort D, Puthusseri B, Fornaro M (2025). The effect of Withania somnifera (Ashwagandha) on mental health symptoms in individuals with mental disorders: systematic review and meta-analysis. Evid Based Ment Health. PMID: 41140145
- Alsanie SA, Alhodieb FS, Askarpour M (2026). Effects of ashwagandha (Withania somnifera) on mental health in adults: A systematic review and dose-response meta-analysis of randomized controlled trials. Complement Ther Med. PMID: 41644067
- Albalawi AA (2025). Dual impact of Ashwagandha: Significant cortisol reduction but no effects on perceived stress - A systematic review and meta-analysis. Nutr Health. PMID: 40746175
- Saqib S, Qureshi A, Ashraf RM, Al-Mussawi T (2024). Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis. Explore (NY). PMID: 39348746
- Di Matteo Della Porta M, Spiga S (2023). Effects of Withania somnifera on Cortisol Levels in Stressed Human Subjects: A Systematic Review. Nutrients. PMID: 38139556
- Dargahi L, Ghasemi F, Gholami M, Mofidi F, Asadi M, Zareei P, Zareei M, Rezaei O, Hekmatdoost A (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. Phytother Res. PMID: 36017529
- Lopresti AL, Smith SJ, Malouf H, Thornton SJ, Shand AA (2019). An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study. Medicine (Baltimore). PMID: 31538356
Note: This article is for informational purposes only, does not constitute medical advice and does not replace consultation with a doctor. Consult a doctor before taking any food supplement — especially with chronic conditions, pregnancy or breastfeeding.
