Ashwagandha: Benefits, Dosage and Precautions

Ashwagandha (Withania somnifera) is a root classified among the rasayanas, Ayurveda's rejuvenating tonics. Its best-supported benefits concern stress, mild anxiety and sleep: several small clinical trials show a drop in cortisol and perceived stress after a few weeks of regular use. Tradition also credits it with strength and vitality — its name means "smell of the horse", a nod to the vigor it is said to confer.

In practical terms: it's a herb worth considering if you're going through a period of nervous tension, poor sleep or background fatigue — provided you choose a quality product and respect a few genuine precautions.

What are the benefits of ashwagandha?

• Stress and mild anxiety: the best-documented use. Randomized clinical trials, still modest in size, find a significant reduction in perceived stress after 6 to 8 weeks.
• Sleep: its species name, somnifera, says it all. The herb seems to make falling asleep easier, especially in stressed people — a gentle effect, not a sleeping pill.
• Vitality and recovery: tradition uses it as a tonic after illness or overwork; a few studies have looked at muscle strength and athletic recovery.
• Male hormonal balance: preliminary data suggest a modest effect on testosterone and male fertility.

In the Ayurvedic framework, ashwagandha calms Vata (nervousness, restlessness, light sleep) and suits Kapha in moderate doses; strongly Pitta constitutions should save it for stressful periods, as it is warming.

Dosage: how to take ashwagandha

For guidance only — the doses commonly seen in practice, to be adjusted with a professional:

Form	Typical dose	When
Root powder (churna)	3 to 6 g per day	In the evening, in warm milk or warm water
Standardized extract (e.g. KSM-66, 5% withanolides)	300 to 600 mg per day	In 1 to 2 doses, preferably in the evening
In the kitchen (moon milk)	1 level teaspoon	Bedtime ritual

Allow 4 to 8 weeks to judge the effect: this is a slow-building herb, not an instant anxiolytic. Tradition takes it as a course of 2 to 3 months, followed by a break. The most pleasant way to take it remains moon milk, the soothing evening drink.

Which ashwagandha should you choose?

The market is flooded with mediocre products. Three markers to look for: a standardized withanolide extract (content stated on the label, usually 2.5 to 5%) or a pure root powder — never an opaque "proprietary blend"; a certificate of analysis confirming the absence of heavy metals; and root material (not leaves, which are far less studied). Our guide to the best ashwagandha details the criteria form by form, and our trustworthy brands checklist applies here to the letter.

Side effects and precautions

Ashwagandha is generally well tolerated at usual doses, but it is not a harmless herb:

• Pregnancy: no. The herb is traditionally advised against during pregnancy. Breastfeeding: medical advice is essential.
• Thyroid: it can stimulate thyroid hormones — absolute caution in case of hyperthyroidism or thyroid medication (levothyroxine).
• Interactions: sedatives, immunosuppressants, diabetes and blood-pressure medications — talk to your doctor or pharmacist.
• Reported cases: a few instances of liver injury have been reported, rare and often linked to products of dubious quality — one more reason to insist on lab testing.
• Digestive: discomfort or loose stools are possible at the start; begin at half dose.

The full picture (at-risk groups, warning signs) is in our article on ashwagandha side effects and dangers and our safety guide.

Ashwagandha or another herb?

For mental restlessness with rumination, tradition prefers brahmi; for stress with depletion in women (cycle, perimenopause), shatavari is often cited; for an everyday boost without a supplement, tulsi tea is the gentlest entry point. Ashwagandha remains the reference choice when stress comes with poor sleep and fatigue.