Ashwagandha is well tolerated by most people, and the usual complaints are digestive upset, headache and drowsiness. Three things matter more than those: rare but documented cases of liver injury, a real effect on thyroid hormones, and that it should be avoided in pregnancy entirely.
The common ashwagandha side effects
At the doses used in trials, 300 to 600 mg a day of extract, most people report nothing. Where side effects appear they are mild.
- Digestive upset. Nausea, loose stools or stomach discomfort. The most frequently reported, and usually worse on an empty stomach.
- Drowsiness. Common enough that many people deliberately take it in the evening.
- Headache. Reported in trials, usually mild.
- Diarrhoea. More likely at higher doses.
Taking it with food and starting at the lower end of the range handles most of this.
Liver injury: rare, real, and worth knowing
This is the one that deserves more space than it usually gets.
A case series published in Liver International documented ten cases of ashwagandha-associated liver injury, five from Iceland and five from the US Drug-Induced Liver Injury Network. The pattern was typically cholestatic or mixed, and one case went to transplant evaluation. Further case reports appeared in 2024 at doses up to around 1,350 mg a day, over periods ranging from days to six months.
Keep the scale in mind. Ashwagandha is consumed by an enormous number of people and these reports are rare. But rare is not zero, and it is a real signal rather than a theoretical worry.
Thyroid: a genuine interaction, not a caution label
Ashwagandha raises thyroid hormone levels. Research shows it increasing T3 and T4 and lowering TSH.
For someone with an underactive thyroid that may sound useful, and it is exactly why it should not be self-prescribed alongside thyroid medication: the two effects stack, and the result can be too much thyroid hormone.
For anyone with an overactive thyroid or Graves’ disease it is a clear contraindication. Adding something that raises thyroid hormone to a condition defined by too much of it is the wrong direction.
Pregnancy: avoid it
This one is not mixed and is worth stating flatly. Ashwagandha should not be taken during pregnancy, in any trimester. Traditional Ayurvedic texts list it as an abortifacient, and modern guidance including the NIH LiverTox resource advises avoidance.
Breastfeeding is a softer no: the concern is an absence of safety data rather than a documented harm. Either way, ask a doctor rather than deciding alone.
Medicines it interacts with
| Medication | Concern |
|---|---|
| Thyroid hormone | Additive effect, may push levels too high |
| Diabetes medication | May lower blood sugar further |
| Blood pressure medication | May lower blood pressure further |
| Sedatives and sleep medication | Additive drowsiness |
| Immunosuppressants | Ashwagandha may stimulate immune activity, working against them |
Anyone on regular medication should check with a pharmacist before starting. It is a short conversation and it covers all of the above.
Who should not take it
- Anyone pregnant, and anyone breastfeeding without medical advice
- Anyone with hyperthyroidism or Graves’ disease
- Anyone with existing liver disease
- Anyone on immunosuppressants, including after a transplant
- Anyone with an autoimmune condition, without medical advice
- Anyone due surgery, because of the sedative effect. Stop two weeks before
How long is it safe to take?
Honest answer: nobody knows beyond the trial windows. Most studies run 8 to 12 weeks and safety data past about three months is limited. That is not evidence of harm, it is an absence of evidence, and it is the reason many practitioners suggest cycling it rather than taking it continuously for years.
What this means if you make ashwagandha products
Three things. Carry the pregnancy warning, because it is the clearest contraindication and it is often missing from labels. Specify root only on your purchase order and your pack, since the research base is root and a label reading just “ashwagandha” is silent on plant part. And keep dose claims tied to the form you are actually selling, because 600 mg of extract and 600 mg of root powder are not comparable.
Adulteration is worth testing for too. This is a high demand ingredient with a wide price range, and cheaper leaf material and fillers are the usual shortcuts.
Sourcing ashwagandha in bulk
We export ashwagandha root powder and ashwagandha extract from India. Root powder minimum is 25 kg, extract is 10 kg. Forms include root powder, extract at 2.5% and 5%, water soluble, full spectrum and certified organic.
Every lot carries a Certificate of Analysis stating plant part, strength, and heavy metal, microbial and pesticide limits. Free sample first, quote back within 24 hours to your port.
Specifications, for buyers who order to a number
Order on plant part, strength and mesh, with purity limits to your market’s pharmacopoeia. Plant part belongs on the order in writing. Strength is confirmed on the Certificate of Analysis for the lot you receive rather than quoted as a range, because it varies with crop and extraction method.
Frequently asked questions
What are the side effects of ashwagandha?
Most commonly mild digestive upset, drowsiness and headache. The more serious concerns are rare cases of liver injury, an effect on thyroid hormone levels, and that it should be avoided in pregnancy.
Can ashwagandha damage your liver?
Rarely, and it is documented. A case series recorded ten instances of ashwagandha-associated liver injury, one of which reached transplant evaluation. Stop and see a doctor if you notice yellowing skin or eyes, dark urine or persistent nausea.
Is ashwagandha safe with thyroid problems?
It raises T3 and T4 and lowers TSH, so it is a clear contraindication in hyperthyroidism and Graves’ disease. Anyone on thyroid medication should not add it without medical supervision, because the effects stack.
Can you take ashwagandha while pregnant?
No. Avoid it in every trimester. Traditional texts list it as an abortifacient and modern guidance advises avoidance. For breastfeeding the issue is a lack of safety data; ask a doctor.
How long can you take ashwagandha for?
Most trials run 8 to 12 weeks and there is limited safety data beyond about three months. That is an absence of evidence rather than evidence of harm, and it is why cycling it is commonly suggested.
Specs change with the crop, the season and the grade. Ask our export desk for a current lab report, the minimum order and a price to your port, and we will come back within 24 hours.