Ashwagandha is one of the few herbal supplements with a reasonable body of human research behind it, which is exactly why its side effects deserve a straight answer rather than either "it's natural, so it's safe" or scare stories.
Most healthy adults tolerate it well. But there are specific groups who should not take it, and specific medicines it can interact with. Here is what to know before you start.
Quick Answer: What Are the Side Effects of Ashwagandha?
The most commonly reported side effects are digestive upset, loose motions, nausea, headache and drowsiness. These are usually mild and often settle by taking it with food or lowering the dose. More seriously, cases of liver injury have been reported, and ashwagandha should not be used in pregnancy because of possible effects on the uterus. It can also interact with thyroid, diabetes, blood pressure, sedative and immunosuppressant medication.
Common Side Effects
| Side effect | What usually helps |
|---|---|
| Stomach upset, nausea | Take with food rather than on an empty stomach |
| Loose motions | Lower the dose; check you are not also taking other herbal supplements |
| Headache | Often settles in the first week; stop if it persists |
| Drowsiness, sedation | Shift the dose to evening — many people take it at night deliberately |
| Grogginess in the morning | Lower the evening dose or move it earlier |
The sedation effect is worth understanding rather than treating as purely a problem. Some people find it helpful at night and disruptive during the day. Our guide on the best time to take ashwagandha covers how to choose.
The Serious One: Liver Injury
This is the side effect that matters most, and it is under-discussed in supplement marketing.
Cases of liver injury associated with ashwagandha have been reported in the medical literature. These are uncommon relative to how many people take it, but they are documented, and several national regulators have flagged them.
Stop taking ashwagandha and see a doctor promptly if you notice:
- Yellowing of the skin or eyes (jaundice)
- Dark urine
- Persistent nausea or vomiting
- Unusual tiredness
- Pain in the upper right abdomen
- Itching without a rash
Do not wait to see if it passes. These are signs to get liver function checked.
If you already have liver disease, or you take medication that affects the liver, do not start ashwagandha without talking to your doctor.
Who Should Not Take Ashwagandha
| Group | Why |
|---|---|
| Pregnant women | Should not be used — possible effects on the uterus |
| Breastfeeding women | Should not be used — safety data are lacking |
| People with liver disease | Liver injury has been reported |
| People with thyroid conditions | Can affect thyroid hormone levels and interact with thyroid medication |
| People with autoimmune conditions | May stimulate immune activity; interacts with immunosuppressants |
| People with hormone-sensitive prostate cancer | May raise testosterone |
| Before scheduled surgery | Stop at least two weeks before, because of sedative effects |
| Under-18s | Insufficient safety data |
Medication Interactions to Check
Tell your doctor or pharmacist you are taking ashwagandha if you use any of these:
- Thyroid hormone medication — ashwagandha may raise thyroid hormone levels, potentially adding to your prescribed dose
- Diabetes medication — possible additive blood-sugar lowering
- Blood pressure medication — possible additive lowering
- Sedatives, sleeping tablets, anti-anxiety medication — additive drowsiness
- Immunosuppressants — ashwagandha may work against them
The thyroid interaction is the one most often missed in India, where thyroid medication is extremely common. If you take levothyroxine, do not start ashwagandha without mentioning it to your doctor.
Does Dose Matter?
Yes. Most human trials have used standardised root extract over periods of eight weeks or more. Side effects tend to appear when people:
- Take more than the label recommends, assuming more is better
- Stack several herbal supplements at once without realising they overlap
- Take it on an empty stomach when their stomach is sensitive
Start at the label dose. There is no evidence that doubling up produces better results, and it raises your risk of the effects above.
How Long Can You Take It?
Most studies have run for eight to twelve weeks. Longer-term safety data are limited, which is an honest gap rather than a known problem.
A sensible approach is to take it for a defined period, assess whether it is actually helping you, and take breaks rather than treating it as something you take indefinitely without review.
What Ashwagandha Is and Is Not
Ashwagandha (Withania somnifera) is an adaptogenic herb used in Ayurveda for centuries. Modern research has mostly looked at stress, sleep quality and exercise performance, with trials generally small and of varying quality.
It is a food supplement. It is not a medicine, it does not treat any medical condition, and it is not a substitute for prescribed treatment or for addressing the actual causes of stress and poor sleep.
For what the research does suggest, see ashwagandha benefits for men.
Choosing a Product
- Root extract is what most research uses. Check the label specifies root
- A stated amount per serving, not a vague proprietary blend
- FSSAI licence number on the pack
- No disease claims — a brand promising to cure anything is one to avoid
- A verified seller — herbal supplements are easy to adulterate, and adulteration is a real cause of unexpected reactions
Frequently Asked Questions
Is it safe to take ashwagandha every day?
Most healthy adults tolerate daily use at label doses in studies running eight to twelve weeks. Longer-term data are limited. Review periodically rather than taking it indefinitely without thought.
Can ashwagandha damage the liver?
Liver injury has been reported in medical literature. It is uncommon, but if you develop jaundice, dark urine, persistent nausea or upper-right abdominal pain, stop and see a doctor.
Does ashwagandha affect the thyroid?
It may raise thyroid hormone levels and can interact with thyroid medication. If you have a thyroid condition or take levothyroxine, check with your doctor first.
Can I take ashwagandha during pregnancy?
No. It should not be used during pregnancy or while breastfeeding.
Does ashwagandha make you sleepy?
It can. Many people take it at night for that reason. If it makes you drowsy during the day, move the dose to the evening.
Can I take ashwagandha with whey protein or creatine?
There is no known interaction between them. The things to check are your prescription medicines, not your sports supplements.
How long before side effects show up?
Digestive effects and drowsiness usually appear in the first week. Liver-related signs, where they occur, have been reported after weeks to months of use.
Browse Denzour herbal supplements, including Denzour Ashwagandha 1000mg.
This article is for general information and is not medical advice. Ashwagandha is a food supplement and is not intended to diagnose, treat, cure or prevent any disease. Consult a qualified healthcare professional before use, especially if you are pregnant or breastfeeding, have a liver, thyroid or autoimmune condition, or take regular medication. Stop use and seek medical advice if you experience signs of liver problems.
