Safety-first Ashwagandha guide · 2026
Ashwagandha side effects: who should avoid it and when to speak to a doctor
Ashwagandha is often marketed as a natural stress or sleep supplement, but “natural” does not mean risk-free. This guide explains common side effects, important medicine interactions, people who should avoid it, and symptoms that require prompt medical attention.
Direct answer
Common reported Ashwagandha side effects include drowsiness, stomach upset, diarrhoea and vomiting. Short-term use may be tolerated by many adults, but long-term safety is not established. Ashwagandha should be avoided during pregnancy and breastfeeding, and it is not recommended for people approaching surgery or those with autoimmune or thyroid disorders unless a qualified clinician specifically advises otherwise. It can also interact with sedatives, anticonvulsants, immunosuppressants, thyroid hormone, diabetes medicines and blood-pressure medicines. Rare cases of liver injury have been reported.
This article is educational, not personal medical advice. Do not use Ashwagandha to replace prescribed treatment or delay evaluation of persistent anxiety, insomnia, fatigue, thyroid symptoms or another health concern.
Safety overview
Ashwagandha side effects at a glance
Side effects are not equally likely or equally serious. A mild stomach symptom after a first dose is different from jaundice or a medication interaction. Use the following three-level framework to decide what action is sensible.
Common or usually mild
Drowsiness, stomach discomfort, loose stools, diarrhoea, nausea or vomiting. Stop and seek advice if symptoms are strong, persistent or worsening.
Needs professional advice
Thyroid symptoms, unexpectedly low blood sugar or blood pressure, excessive sedation, worsening autoimmune symptoms, or a possible medicine interaction.
Potentially urgent
Yellow skin or eyes, dark urine, pale stools, severe abdominal pain, facial swelling, breathing difficulty, fainting or confusion need prompt medical assessment.
Short-term does not mean risk-free. The U.S. National Center for Complementary and Integrative Health states that Ashwagandha may be safe for short-term use—up to about three months—but there is not enough information to conclude that long-term use is safe.
Most frequently reported
What are the common side effects of Ashwagandha?
The most consistently listed side effects from major health authorities are gastrointestinal symptoms and drowsiness. They may be more noticeable when a product is taken on an empty stomach, when the serving is increased too quickly, or when it is combined with other sedating ingredients.
| Possible effect | What it may feel like | Practical response | When to contact a clinician |
|---|---|---|---|
| Drowsiness | Sleepiness, slowed alertness or feeling unusually relaxed. | Do not drive or operate machinery if affected. Avoid combining it with alcohol or sedating products. | If sedation is strong, unexpected, persistent or occurs with prescribed sedatives. |
| Stomach upset | Discomfort, cramping, nausea or indigestion. | Check label directions and whether the product permits use with food. | If pain is severe, repeated or associated with vomiting, dehydration or blood. |
| Diarrhoea | Loose or frequent stools. | Stop the product if symptoms are more than mild and maintain hydration. | If diarrhoea is persistent, severe, bloody, or causes dizziness and dehydration. |
| Vomiting | Feeling or being sick. | Stop taking the product and do not repeat the dose to “make up” for it. | If vomiting continues, is severe, or prevents fluid intake. |
Less common but important
Can Ashwagandha cause serious side effects?
Serious reactions appear to be uncommon, but uncommon does not mean impossible. The most important concerns discussed by health authorities are potential liver injury, effects on thyroid hormone, excessive sedation, changes in blood glucose or blood pressure, and interactions with medicines.
Rare liver injury reports
Cases linking Ashwagandha supplements with liver injury have been reported. A person should not wait for symptoms to become severe before seeking help.
Thyroid effects
Ashwagandha may affect thyroid function. This matters especially for people with thyroid disease or those using thyroid hormone medicines.
Blood sugar and blood pressure
Ashwagandha may add to the effects of diabetes or blood-pressure medicines, potentially making levels lower than intended.
Immune and nervous-system effects
It may conflict with immunosuppressants, sedatives or anticonvulsants. Combining multiple products can make the total effect difficult to predict.
Do not self-start
Who should avoid Ashwagandha?
Based on current NCCIH safety guidance, the following groups should avoid Ashwagandha or should not use it unless a suitably qualified healthcare professional has reviewed the situation.
Pregnant people
Ashwagandha should be avoided during pregnancy. Do not treat a “natural” or traditional label as proof of pregnancy safety.
People who are breastfeeding
NCCIH advises that Ashwagandha should not be used while breastfeeding because safety information is insufficient.
People approaching surgery
Ashwagandha is not recommended for people about to have surgery. Tell the surgical and anaesthesia team about every supplement being used.
People with autoimmune disorders
Because Ashwagandha may affect immune activity, self-use can be unsuitable for people with autoimmune conditions or those using immunosuppressants.
People with thyroid disorders
It may affect thyroid hormone levels and may interact with thyroid medication. Thyroid disease requires clinician-guided decisions.
Hormone-sensitive prostate cancer
NCCIH advises avoidance because Ashwagandha may increase testosterone levels in some settings.
Children and teenagers: do not assume an adult supplement is appropriate for a child. Paediatric safety, formulation and dosing require professional guidance.
Personal risk review
Who should speak to a doctor or pharmacist before taking Ashwagandha?
A pre-use conversation is sensible whenever a health condition, medicine or planned procedure could change the risk. A pharmacist can often identify ingredient duplication and medicine interactions even when the supplement was bought online.
- Anyone taking prescription medicines or several supplements together.
- People with liver disease, previous unexplained liver-test abnormalities or a past supplement-related liver reaction.
- People with diabetes, low blood sugar, high or low blood pressure.
- People with thyroid disease, autoimmune disease, seizure disorders or significant sleepiness.
- People receiving cancer treatment, hormone-related treatment or immune-modifying therapy.
- Anyone scheduled for surgery, sedation, dental surgery or an invasive procedure.
- Older adults, people with multiple conditions, or anyone who is frail or prone to falls.
- Anyone using Ashwagandha because of persistent anxiety, insomnia, fatigue, weight change or palpitations that have not been medically assessed.
Medication safety
Which medicines may interact with Ashwagandha?
An interaction does not occur in every user, but the possibility is important enough that NCCIH identifies several medication groups. Do not stop, reduce or move a prescribed dose without speaking to the prescriber.
| Medicine category | Why the combination matters | Examples of what to monitor | Recommended action |
|---|---|---|---|
| Sedatives and sleep medicines | Ashwagandha can cause drowsiness and may add to sedating effects. | Excessive sleepiness, slowed reactions, falls or confusion. | Ask a doctor or pharmacist before combining. |
| Anticonvulsants | Potential nervous-system effects and interaction concerns. | Changes in alertness, seizure control or medicine effects. | Do not self-combine with anti-seizure medication. |
| Immunosuppressants | Ashwagandha may affect immune activity in the opposite direction to treatment goals. | Disease flare, altered treatment response or unexpected symptoms. | Use only with the treating specialist’s approval. |
| Thyroid hormone medicines | Ashwagandha may affect thyroid hormone levels. | Palpitations, tremor, heat intolerance, sweating, anxiety or weight change. | Discuss before use and follow the clinician’s monitoring plan. |
| Diabetes medicines | Blood glucose may fall more than intended. | Sweating, shakiness, dizziness, confusion or low readings. | Seek individual advice; do not alter diabetes medicine yourself. |
| Blood-pressure medicines | Blood pressure may fall more than intended. | Light-headedness, faintness, falls or unusually low readings. | Speak to a clinician or pharmacist before combining. |
Also disclose alcohol, cannabis, antihistamines and other sleep supplements. Even when something is not a prescription medicine, combining several sedating products may impair alertness.
Rare but significant
Can Ashwagandha affect the liver?
Major health authorities state that a number of cases have linked Ashwagandha supplements with liver injury, although the reaction appears to be rare. A case report does not mean every product will injure the liver, but it does justify clear warning signs and prompt action.
Possible liver-warning symptoms
- Yellowing of the skin or whites of the eyes.
- Dark urine or unusually pale stools.
- Persistent itching without a clear explanation.
- Severe or persistent nausea, vomiting or loss of appetite.
- Pain or discomfort in the upper-right abdomen.
- Unusual fatigue together with any of the symptoms above.
Do not restart the same product after a suspected liver reaction unless a clinician who knows the case advises it. Keep the bottle, packaging, batch details and complete ingredient list for the medical assessment.
Hormone considerations
Can Ashwagandha affect thyroid function?
Research and safety reviews have raised concerns about effects on thyroid hormone levels and reports of thyroid toxicity. People with an overactive or underactive thyroid—and anyone using levothyroxine or another thyroid medicine—should not treat Ashwagandha as an ordinary wellness add-on.
Symptoms worth reporting
- New palpitations or a fast heartbeat.
- Tremor, sweating or heat intolerance.
- Unexpected weight loss or marked anxiety.
- Unusual tiredness, cold intolerance or weight change.
What not to do
- Do not change thyroid medicine based on supplement marketing.
- Do not use symptoms alone to diagnose a thyroid change.
- Do not assume “root-only” means no thyroid effect.
- Do not skip recommended thyroid blood tests.
Product differences matter
Do dose, extract type and format change the side-effect risk?
They can. “Ashwagandha 600 mg” does not fully describe a product. The number may refer to whole-root powder, a concentrated extract, a proprietary extract, one capsule or a full daily serving. Withanolide standardisation and added ingredients can also differ.
| Label feature | Why it matters | What to verify |
|---|---|---|
| Whole-root powder | A larger milligram number may represent less concentrated plant material than an extract. | Serving size, number of capsules and plant part. |
| Standardised extract | Concentration and withanolide content can affect exposure. | Extract name, standardisation percentage and amount per serving. |
| Root-and-leaf extract | Root and leaf have different chemical profiles. | Exact plant parts rather than assuming all formulas are root-only. |
| Combination formula | Another herb, mineral, sedative ingredient or bioavailability enhancer may cause the reaction. | The complete ingredient list and amounts. |
| Multiple daily servings | The front-label number may be per capsule rather than total daily intake. | Directions, capsules per serving and maximum daily serving. |
Do not respond to side effects by experimenting with several brands. Switching products while symptoms continue makes it harder to identify the cause and may delay appropriate care.
Action guide
When should you stop Ashwagandha and speak to a doctor?
Contact a clinician soon
Persistent vomiting or diarrhoea, marked drowsiness, palpitations, tremor, repeated dizziness, low glucose readings, low blood-pressure symptoms, or a worsening health condition.
Seek urgent medical help
Jaundice, dark urine with pale stools, severe abdominal pain, collapse, breathing difficulty, swelling of the face or throat, confusion, a seizure, or another severe reaction.
Stop before an upcoming procedure
Tell the surgeon, dentist and anaesthesia team exactly what you take. Follow their specific stopping instructions rather than choosing your own interval.
Report a suspected reaction
Keep the product name, brand, batch number, purchase source, serving used, start date, other medicines and symptom timeline.
Do not wait for an online answer during an emergency
If symptoms are severe, rapidly worsening, or involve breathing, consciousness, a seizure, collapse or yellowing of the eyes or skin, use your local emergency or urgent medical service.
Before the first serving
A safer-use checklist for adults considering Ashwagandha
- Check suitability first: review pregnancy, breastfeeding, surgery, thyroid, autoimmune, liver, blood-pressure, glucose and medicine considerations.
- Choose one clearly labelled product: confirm plant part, extract type, serving amount, standardisation and complete ingredient list.
- Follow the physical label: do not copy another brand’s dosage or rely only on the product-page title.
- Avoid unnecessary combinations: especially multiple sleep products, sedating herbs or several Ashwagandha formulas.
- Start only when you can observe tolerance: not before driving, a major trip, surgery or an important workday.
- Record the start date and serving: this helps if symptoms appear.
- Stop when a concerning symptom begins: do not keep using it to “see whether the body adjusts” when symptoms are significant.
- Review ongoing need: long-term safety is uncertain; repeated indefinite use deserves professional review.
Available at Buy Herb India
Compare Ashwagandha products by label clarity—not by the biggest number
The following examples represent different Ashwagandha formats currently listed by Buy Herb India. They are not recommendations for people in an avoid or caution group. Verify the current online listing and the delivered physical pack before use.
Nutrabud Ashwagandha KSM-66
A 500 mg KSM-66 listing. Suitability still depends on medicines, conditions, serving directions and individual tolerance.
- FormatCapsules
- Label focusKSM-66 500 mg
- VerifyWarnings and full ingredients
Zandu Ashwagandha KSM-66
A 600 mg KSM-66 listing. A higher front-label number is not proof of greater safety, suitability or benefit.
- FormatVerify current pack
- Label focusKSM-66 600 mg
- VerifyServing basis and warnings
Organic India Pure Ashwagandha Root
A whole-root capsule option. Whole-root positioning does not remove pregnancy, thyroid, medicine-interaction or liver precautions.
- FormatCapsules
- Label focusPure Ashwagandha root
- VerifyDaily serving and cautions
Product accuracy note: Product names, images, ingredients, pack formats and directions may change. Use the delivered pack—not this article—as the final source for the specific product’s ingredient list, serving and warnings.
People also ask
Frequently asked questions about Ashwagandha side effects
What is the most common side effect of Ashwagandha?
Major health sources commonly list drowsiness and gastrointestinal effects such as stomach upset, diarrhoea and vomiting. Individual reactions vary by product, serving and personal health.
Can Ashwagandha make you sleepy?
Yes. Drowsiness is a recognised possible side effect. Avoid driving or operating machinery if affected, and use extra caution with alcohol, sleep medicines, sedating antihistamines or other calming supplements.
Can Ashwagandha upset your stomach?
Yes. Stomach upset, diarrhoea and vomiting have been reported. Stop and obtain advice if symptoms are significant, repeated, worsening or associated with dehydration, severe pain or blood.
Can Ashwagandha damage the liver?
Rare cases linking Ashwagandha supplements with liver injury have been reported. Yellow eyes or skin, dark urine, pale stools, persistent itching or significant upper-abdominal pain need prompt medical evaluation.
Is Ashwagandha safe during pregnancy?
NCCIH advises that Ashwagandha should be avoided during pregnancy. A pregnant person should not self-use it based on traditional-use claims or online recommendations.
Can I take Ashwagandha while breastfeeding?
NCCIH advises that Ashwagandha should not be used while breastfeeding because adequate safety information is not available.
Can people with thyroid problems take Ashwagandha?
Ashwagandha is not recommended for people with thyroid disorders without professional guidance. It may affect thyroid hormone levels and interact with thyroid hormone medication.
Should Ashwagandha be stopped before surgery?
People approaching surgery should not use Ashwagandha without guidance. Tell the surgical and anaesthesia team about it and follow their exact instructions on when to stop.
Can Ashwagandha interact with antidepressants?
The interaction depends on the specific medicine and the person. Because Ashwagandha may cause drowsiness and is used for stress-related reasons, anyone taking an antidepressant or other psychiatric medicine should ask the prescriber or pharmacist before combining them.
Is it safe to take Ashwagandha every day for years?
Long-term safety is not established. NCCIH states that short-term use up to about three months may be safe for some people, but there is insufficient information to conclude that months or years of continuous use is safe.
Does a lower dose guarantee no side effects?
No. A lower serving may reduce exposure but cannot guarantee safety. Product concentration, other ingredients, medicines, health conditions and individual sensitivity all matter.
What information should I give a doctor after a suspected reaction?
Provide the product and brand name, photographs of the label, batch number, serving used, start and stop dates, symptom timeline, all medicines and supplements, and where the product was purchased.
Evidence and safety references
Sources used for this guide
- National Center for Complementary and Integrative Health: Ashwagandha—Usefulness and Safety.
- NIH Office of Dietary Supplements: Ashwagandha Health Professional Fact Sheet.
- UK Food Standards Agency: Ashwagandha safety call for evidence and risk considerations.
- NHS: Jaundice and urgent medical advice.
- Buy Herb India: Stress & Rest collection.
Medical disclaimer: This content is for general educational purposes and does not diagnose, treat, cure or prevent disease. Supplement suitability depends on age, health conditions, medicines, pregnancy or breastfeeding status, planned procedures and the exact formulation. Speak with an appropriate healthcare professional for personal advice. Product availability and labels may change.