Side Effects Of Ashwagandha: 5 Things To Be Aware Of

Side effects of ashwagandha

Ayurveda, the traditional Indian medicinal system, recommends ashwagandha or Withania somnifera as a key herb to be used as a daily tonic to increase vitality and longevity. The recommended dosage is 3–12 g daily of ashwagandha root or leaf powder or 300–1200 mg daily of ashwagandha root or leaf extract. But does ashwagandha have any side effects?

1. Ashwagandha Has No Major Side Effects, As Per Human Studies

In the recent past, several human studies have been conducted to assess the impact of ashwagandha on a variety of disorders, including stress, metabolism, fatigue, neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease, and male fertility. Within the recommended effective dosage range (300–1200 mg daily), no side effects have been reported, either for short-term or long-term usage.


Individual Components Or Pure Alkaloid Extracts May Be Toxic But The Whole Herb Is Not

However, it has been found that very high doses (450–1500 mg/kg of body weight) of pure alkaloid extract (alkaloids constitute 2% of the herb) is toxic. Water extract, on the other hand, did not induce any toxicity, even at levels as high as 2000 mg/kg – which is about 50 times the recommended dosage (of herb extract) for humans.1

[pullquote]While individual components of ashwagandha, such as withaferin A, might be toxic even at low doses, the whole herb is not toxic even at high doses. Staying within the recommended dosage of 3–12 g root or leaf powder or extract should not ideally have any side effects.[/pullquote]


Consuming isolated active constituent of ashwagandha, such as withaferin A, instead of the whole herb or herb extract may also cause toxicity. Radiation biologists studying the effect of ashwagandha on cancer demonstrated that the cumulative doses of ashwagandha extract (500–750 mg/kg daily) did not show any toxicity, while pure withaferin A was toxic even at a low dose.

This is probably because the components of the crude extracts interact to create a synergy of cancer cell-killing effects or neutralize each other’s toxicity.2


In simple words, the whole herb may be much more safe and effective than its isolated active constituents. This is in line with modern medical research, which, influenced by advances in systems biology and functional genomics perspective, is moving away from mono-molecular or single-target approach to combinations and multiple-target strategies.

2. Ashwagandha Overdose May Cause Minor Side Effects

The minor side effects of an ashwagandha overdose include nausea, vomiting, stomach upset, and diarrhea. Some people may also be allergic to the herb.3


3. Ashwagandha May Aggravate Pitta Disorders

As per ayurvedic theory, ashwagandha increases pitta (a dosha that represents the tendency to transform) and pacifies kapha (which represents the tendency to accumulate) and vata (which represents the tendency to flow). Disorders are a manifestation of imbalance in these 3 basic humors. For example, lack of sufficient pitta will show up in the form of sluggish metabolism, indigestion, accumulation of toxins, and loss of memory.

Ashwagandha is recommended to overcome and correct pitta deficiency. Conversely, those with excess pitta should be careful while consuming ashwagandha, since it may aggravate disorders caused by excess pitta, such as acidity, ulcers, skin rashes, and anxiety.


4. Ashwagandha May Interact With Certain Drugs

Ashwagandha may interact with certain drugs by enhancing or negating their actions.

  • Sedatives: Since ashwagandha can both energize and induce restorative sleep, it might negate or amplify the effect of other sedative drugs, especially the benzodiazepines. Do note that ashwagandha itself does not act as a sedative.
  • Immunosuppressants: Being an adaptogen – something that has the ability to modulate an immune response – ashwagandha might also interact with or reduce the effects of drugs that suppress the immunity. So it must not be consumed by people with autoimmune disorders.
  • Antidiabetic drugs: Ashwagandha is as effective as standard drugs for diabetics. It has been seen to reduce blood glucose levels by 12%.4 So if you are already taking medicines for blood sugar, ashwagandha might amplify its effect and bring your blood glucose to an abnormally low level.
  • Antihypertensive drugs: Since ashwagandha can also lower high blood pressure, it may not be ideal to take it in conjunction with an antihypertensive drug.
  • Thyroid medicines: While a perfectly calibrated dose of ashwagandha can balance your thyroid hormone levels and optimize your metabolism, it should not be taken with a thyroid medicine, whether meant for treating hypothyroidism or hyperthyroidism.

5. Ashwagandha Is Not Suited For Pregnant And Breastfeeding Women

Some sources mention that ashwagandha may induce abortion, which is why it is not recommended for use by pregnant women. It should also be used with caution by young children and breastfeeding women. It is also to be used with caution by those suffering from liver problems and stomach ulcers and those preparing for surgery.


These observations are, however, based on the properties of ashwagandha root and leaf extract (not based on any human studies that report adverse effects) and may be applicable only if the dosage is beyond recommended range. It’s best to consult a doctor, in any case.