Podcast episode 41 (in German)
Ashwagandha: the stress herb fact-checked
August 14, 2026
The root has been used against stress in Ayurveda for around 3,000 years, and there are now more than 60 human studies. Ashwagandha is one of the rare cases in which tradition and randomized trials arrive at the same result: less cortisol, better sleep.
What it is about
Ashwagandha, botanically Withania somnifera, is a member of the nightshade family; the Sanskrit name means “smell of the horse”, the species name “sleep-inducing”. As an adaptogen it is said to help the body adapt to stress, carried by the withanolides to which good extracts such as KSM-66 or Sensoril are standardized. The episode goes through the studies: on cortisol and perceived stress, sleep, anxiety, stress eating, strength, testosterone, fertility and endurance. It explains the route via the stress axis and the GABA system and puts the liver debate into context. What remains is one of the best-studied herbal tools against chronic stress, with clearly named groups who need to be cautious.
Key points
- In the study by Chandrasekhar and colleagues in 2012, perceived stress in chronically stressed adults fell by more than 40 percent and cortisol by almost 28 percent compared with placebo after 60 days.
- A 2025 meta-analysis confirms the reduction in cortisol as a consistent, measurable effect; for the subjective feeling of stress, the results are more mixed.
- In people with sleep disorders, ashwagandha shortened the time to fall asleep and improved sleep efficiency in the study by Langade and colleagues in 2019.
- In the study by Wankhede and colleagues in 2015, young men doing 8 weeks of strength training with ashwagandha gained markedly more on the bench press than with placebo, along with more muscle and testosterone.
- In 2017, Choudhary and colleagues found less food craving and stress eating and significantly more weight loss than with placebo in chronically stressed people with overweight.
- In men with low sperm counts, sperm concentration and testosterone rose in a 2013 study; in women, desire and satisfaction improved in a 2015 study.
- The German Federal Institute for Risk Assessment (BfR) issued a warning in September 2024 after rare cases of liver damage; in 2025, an observational study of 12 months of continuous use found no liver signals.
Where the data stop
Best supported is the reduction in cortisol, and sleep is well supported; strength, hormones and fertility rest on solid individual studies, cognition and endurance on signals with rather small effects. The subjective feeling of stress does not improve equally for everyone, and in genuine anxiety disorders ashwagandha does not replace treatment. Occasionally, gastrointestinal complaints or daytime tiredness occur; at high amounts, some report emotional blunting.
The liver cases are very rare but serious: anyone who has liver disease or is pregnant or breastfeeding should clarify use with a physician beforehand, and the warning also applies to children. With dark urine or yellowing, stop immediately. Caution also applies with an overactive thyroid, autoimmune diseases and together with sedatives.
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Published on August 14, 2026.
The topic in the database
- The best-known adaptogen. Small RCTs show lower cortisol levels and less perceived stress – mostly over eight weeks and with manufacturer-linked extracts…Ashwagandha
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-10-09.