Contents 6 min reading
Important Note
This page is not medical advice. Although Ashwagandha's potential benefits are supported by research, it should not be used to treat any health problems. Consult a healthcare professional.
What is Ashwagandha?
Ashwagandha (Withania somnifera) is a perennial plant from the Solanaceae family, growing in India, the Middle East and some parts of Africa. Its name, which means "horse scent" in Sanskrit, refers both to the unique smell of the root of the plant and to the idea that it conveys the strength and endurance of the horse to the user, according to traditional beliefs.
Ashwagandha has been used as a "rasayana" (rejuvenating tonic) in Ayurvedic medicine for over 3000 years. adaptogenic herb falls into the category. Adaptogens; They are substances that increase the body's resistance to stress, support homeostasis and have a normalizing effect on multiple physiological systems.
Two important standard extract forms stand out in the market. KSM-66, derived from the root only and documented to contain 5% withanolide, is the most commonly used form in clinical studies. sensory is a full spectrum extract obtained from both root and leaf; It has a higher withanolide concentration (10%) but is used in lower doses (125–250 mg/day). Both forms are supported by clinical evidence; The choice largely depends on the goal and budget.
Mechanism of Effect
Ashwagandha's broad range of effects is due to its simultaneous action on multiple physiological systems. This multi-target structure is the basis of the plant's adaptogenic properties.
HPA axis and cortisol regulation: Ashwagandha's best documented mechanism is that it normalizes the hypothalamic-pituitary-adrenal (HPA) axis. This axis, which is overactivated under chronic stress, increases cortisol secretion. Withanolides regulate this secretion through their effects on cortisol receptors and the adrenal gland; In clinical studies, a 14–28% decrease in serum cortisol levels was observed.
GABA modulation: Withanolide A and cytoindoside VII, the active ingredients of Ashwagandha, can increase GABAergic activity by interacting with GABA-A receptors. This effect; It partially explains the anxiolytic effect, shortening sleep latency and prolonging the duration of deep sleep.
Thyroid hormone support: Animal and limited human studies suggest that Ashwagandha may increase T3 and T4 thyroid hormone levels. Although it represents potential support for people with hypothyroidism, it requires caution in cases of hyperthyroidism and carries the risk of drug interactions.
Effect of testosterone and DHEA: In RCTs in male participants, Ashwagandha use was associated with a significant increase in serum testosterone level. Mechanism; It includes the reduction of the negative effect of cortisol decrease suppressing testosterone synthesis and possible modulation on luteinizing hormone (LH).
| compound | Target System | Impact |
|---|---|---|
| Withanolide A, B | HPA axis, immune system | Cortisol lowering, anti-inflammatory |
| Withanolide D | androgen system | Testosterone and DHEA increase |
| withaferins | NF-κB pathway | Anti-inflammatory, neuroprotective |
| Cytoindoside VII, VIII | GABA-A receptor | Anxiolytic, improved sleep quality |
| Alkaloids (somniferine) | CNS, thyroid gland | Calming effect, thyroid support |
Clinical Evidence
Ashwagandha has the most comprehensive RCT database among adaptogens. There is particularly strong evidence in the areas of stress, cortisol, sleep and athlete performance.
Chandrasekhar et al. (2012), in a 60-day double-blind, placebo-controlled study of 64 people with chronic stress, found that KSM-66 (300 mg twice daily) reduced serum cortisol by an average of 27.9% compared with placebo. Significant improvement was also observed on the Perceived Stress Scale (PSS).
Raut et al. (2012)reported that KSM-66 was well tolerated in the 8-week safety study, with no hepatotoxicity or serious side effects observed. No significant negative changes were detected in weight, blood pressure and laboratory parameters.
Wankhede et al. (2015)reported that testosterone levels increased significantly and muscle strength and muscle mass gains were higher in the group receiving 2x300 mg (600 mg/day) of KSM-66 in addition to an 8-week resistance training protocol in 57 healthy men compared to the placebo group.
Langade et al. (2019)showed that full-spectrum Ashwagandha root extract (300 mg, twice daily) significantly improved sleep onset latency, total sleep time, and sleep efficiency compared to placebo in 60 insomnia patients. Morning alertness and general well-being were also found to be superior to placebo.
Dosage Protocol
The effective dose for Ashwagandha varies depending on the extract form used and the target. Both standard forms can be taken in divided doses in the morning and night or in a single dose at night.
| Purpose | Dose | Timing | form |
|---|---|---|---|
| Stress and cortisol regulation | 300 mg x2/day or 600 mg at night | morning + night | KSM-66 |
| sleep quality | 300–600 mg | 1 hour before bed | KSM-66 or Sensoril |
| Anxiety support | 300 mg x2/day | Morning + noon | KSM-66 |
| Athlete performance / testosterone | 300–600 mg/day | Pre-workout or in the morning | KSM-66 |
| General adaptogenic support (Sensoril) | 125–250 mg/day | morning or night | sensory |
KSM-66 vs Sensoril: KSM-66 is solely root-based and is closer to traditional Ayurvedic use; It is the preferred form in most clinical studies. Sensoril is full spectrum and contains more concentrated withanolide; Therefore, it requires lower grammage, but it may require attention in some autoimmune complaints because it contains leaf-derived components.
⚠ Attention to Those Using Thyroid Medications
Ashwagandha may increase thyroid hormone levels (T3/T4). Those using thyroid medications (levothyroxine, etc.) should definitely consult their doctor before starting Ashwagandha. Dosage adjustment may be required.
Safety and Side Effects
Ashwagandha demonstrated a safe profile at standard doses and short-to-medium-term use (8–16 weeks). However, there are some situations that need to be taken into consideration.
- Pregnancy and breastfeeding: NEVER use. Ashwagandha has uterotonic (uterine contraction-stimulating) effects; Use during pregnancy may increase the risk of miscarriage.
- Stomach upset: Mild nausea and digestive upset have been reported with high doses or when taken on an empty stomach. It is recommended to take with food.
- Drowsiness/sedation: Due to its GABAergic effect, it may cause mild drowsiness in some people when taken during the day. Those operating heavy machinery should be careful.
- Autoimmune diseases: Ashwagandha may stimulate the immune system; A doctor's opinion should be obtained regarding use in people with autoimmune diseases such as rheumatoid arthritis, lupus or multiple sclerosis.
- Rarely reported liver toxicity: There are very rare case reports in the literature; The mechanism is unclear and possible contributing factors (high dose, long-term use) remain unclear.
Drug interactions:
- Thyroid medications: It can increase T3/T4 levels; dose adjustment may be required.
- Immunosuppressants: It may conflict with immunosuppressive treatments due to its immunostimulating effect.
- Sedatives and anxiolytics: There is a risk of synergistic sedation when used with its GABAergic effect.
- Antidiabetic drugs: It may lower blood sugar; Those who use insulin or oral antidiabetics should be careful.
Sources
- Chandrasekhar K, Kapoor J, Anishetty S. (2012). A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine, 34(3), 255–262. PubMed · PMID 23439798
- Raut AA, et al. (2012). Exploratory study to evaluate tolerability, safety, and activity of Ashwagandha (Withania somnifera) in healthy volunteers. Journal of Ayurveda and Integrative Medicine, 3(3), 111–114. PubMed · PMID 23125505
- Wankhede S, et al. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial. Journal of the International Society of Sports Nutrition, 12, 43. PubMed · PMID 26609282
- Langade D, et al. (2019). Efficacy and safety of Ashwagandha (Withania somnifera) root extract in insomnia and anxiety: a double-blind, randomized, placebo-controlled study. Cureus, 11(9), e5797. PubMed · PMID 31728244
- Pratte MA, et al. (2014). An alternative treatment for anxiety: a systematic review of human trial results reported for the Ayurvedic herb ashwagandha (Withania somnifera). Journal of Alternative and Complementary Medicine, 20(12), 901–908. PubMed · PMID 25405876
Link verification checks the identity of the publication; it does not constitute independent expert review of clinical claims. Our evidence and source methodology · Source directory
Frequently Asked Questions
Ashwagandha reduces stress and anxiety, improves sleep quality and strengthens the body's resistance to stress, mainly by lowering cortisol levels. Thanks to its adaptogenic structure, it provides support against both mental and physical fatigue; Additionally, positive effects on testosterone levels and muscle strength have been observed in athletes.
Ashwagandha is not an instant-acting substance; The effects become apparent within 2 to 4 weeks with regular use. In clinical studies, the most significant results were generally measured after 8 weeks of use. Therefore, it is recommended to plan a protocol of at least 4–8 weeks.
The standard dose for the KSM-66 form is 300–600 mg daily; It is usually taken divided into two in the morning and at night. Since the sensoril form is more concentrated, 125–250 mg/day is sufficient. If the target is sleep quality, it may be preferable to take a single dose 1 hour before bedtime. Individual tolerance and target should be taken into consideration when determining the dose.
At standard doses and within recommended durations (8–16 weeks), Ashwagandha is generally well tolerated. The most commonly reported side effects are mild nausea and digestive upset; These can be reduced by taking them with food. Its use during pregnancy is definitely not recommended because it may stimulate uterine contractions. Since there is a risk of interaction with thyroid medications, sedatives or immunosuppressants, those taking these medications should consult a doctor.
Ashwagandha is sold as a food supplement, not a medicine, in Türkiye, and its legal status is generally unproblematic. KSM-66 or Sensoril certified products are available from various supplement stores and online platforms. When purchasing, choosing brands that have a third-party test certificate (CoA) and whose standard withanolide content (5 or more) is clearly stated ensures quality.
