Reviewed by the Celnovix Editorial Team
Last reviewed: September 2026
Ashwagandha is often described as a:
natural adaptogen.
But “natural” does not mean:
risk-free.
Most short-term clinical trials suggest that standardized ashwagandha root extracts are generally well tolerated in healthy adults.
The most commonly reported side effects are usually mild and can include:
- Stomach upset
- Loose stools
- Nausea
- Drowsiness
- Headache
However, several more important safety questions deserve attention.
Ashwagandha has also been associated with:
- Rare liver injury
- Changes in thyroid hormones
- Potential drug interactions
- Sedation
- Immune-system effects
And long-term safety beyond several months remains:
incompletely established.
So the correct conclusion is not:
“Ashwagandha is dangerous.”
Nor is it:
“Ashwagandha is completely safe because it is an herb.”
The evidence supports a more nuanced answer.
Ashwagandha Side Effects: Quick Answer
For most healthy adults using standardized root extracts in studied doses, short-term tolerability appears:
generally favorable.
Possible side effects include:
More Common or Mild
- Stomach discomfort
- Loose stools
- Nausea
- Drowsiness
- Headache
Less Common but More Important
- Liver injury
- Excessive thyroid-hormone effects
- Medication interactions
- Allergic or hypersensitivity reactions
People Who Need Extra Caution
Those who:
- Are pregnant
- Are breastfeeding
- Have thyroid disease
- Have liver disease
- Have autoimmune disease
- Take sedatives
- Take thyroid medication
- Take diabetes medication
- Take blood-pressure medication
- Take immunosuppressants
- Are preparing for surgery
Is Ashwagandha Safe?
For short-term use in generally healthy adults:
probably for many people.
But that answer needs context.
A 2026 systematic review specifically evaluated:
standardized ashwagandha root extract
in healthy adults.
It included:
23 studies
and:
2,317 participants.
The reviewed doses ranged from approximately:
125–600 mg/day
and intervention durations ranged from:
a single dose to 180 days.
Across those studies:
- Liver markers remained within normal clinical ranges
- Kidney markers remained within normal ranges
- Hematologic markers remained stable
- Cardiovascular markers showed no clinically meaningful adverse changes
- No serious adverse events attributable to the standardized root extract were reported
Mild adverse events were uncommon and included:
- GI discomfort
- Headache
- Temporary drowsiness
View the 2026 systematic review on PubMed
That sounds reassuring.
But there is an important limitation:
The review mainly tells us about standardized root-only products used for up to six months in selected trial populations.
It does not prove that every:
- Extract
- Root-and-leaf formulation
- High-dose product
- Multi-ingredient supplement
- Multi-year use pattern
has the same safety profile.
What Are the Most Common Side Effects of Ashwagandha?
According to clinical trials and NIH safety summaries, the most commonly reported adverse effects include:
- Stomach upset
- Loose stools
- Nausea
- Vomiting
- Drowsiness
These are usually:
mild and temporary.
1. Stomach Upset
GI discomfort is one of the most common complaints.
This may include:
- Abdominal discomfort
- Nausea
- Cramping
- Indigestion
Some people find that taking ashwagandha:
with food
improves tolerance.
2. Diarrhea or Loose Stools
Ashwagandha can cause:
- Loose stools
- Diarrhea
in some users.
This may be more likely with:
- Higher doses
- Sensitive stomachs
- Certain extracts
- Multi-ingredient formulas
Persistent diarrhea should not be treated as:
a detox reaction.
3. Nausea
Mild nausea has been reported in clinical use.
Possible strategies include:
- Taking it with food
- Reducing unnecessary high doses
- Reassessing the specific product
If nausea is persistent or severe, discontinuing the supplement may be more appropriate than trying to:
push through it.
4. Drowsiness
Some people experience:
sleepiness or sedation.
This makes sense given that ashwagandha is frequently studied in relation to:
- Stress
- Relaxation
- Sleep
But drowsiness should not automatically be interpreted as:
evidence that the supplement is working.
Does Ashwagandha Make You Sleepy?
It can.
But not everyone experiences this effect.
If ashwagandha causes noticeable drowsiness, be cautious with activities requiring alertness such as:
- Driving
- Operating machinery
- Working at height
especially when first evaluating your response.
5. Headache
Headache has occasionally been reported in clinical studies.
It is generally described as:
mild and temporary.
But recurrent headache after starting a supplement deserves reassessment.
Can Ashwagandha Cause Serious Side Effects?
Rarely:
yes.
The most important serious safety signal currently associated with ashwagandha is:
liver injury.
Ashwagandha and Liver Injury
Over the past several years, case reports and case series have described:
ashwagandha-associated liver injury.
This appears to be:
rare.
But rare does not mean:
imaginary.
What Does the 2026 Liver Review Show?
A 2026 scoping review systematically evaluated published clinical reports of ashwagandha-associated liver injury.
The review identified:
13 publications
covering:
25 patients.
Liver injury generally developed after:
weeks of use.
The most common patterns were:
- Cholestatic injury
- Mixed liver injury
rather than purely hepatocellular injury.
Common presenting symptoms included:
- Jaundice
- Itching
- Fatigue
What Is Cholestatic Liver Injury?
Cholestasis means that normal:
bile flow
is impaired.
Symptoms can include:
- Yellow skin or eyes
- Severe itching
- Dark urine
- Pale stools
Blood tests may show changes involving:
- Bilirubin
- Alkaline phosphatase
- Liver enzymes
What Is Mixed Liver Injury?
Mixed injury means laboratory patterns show features of both:
- Hepatocellular injury
- Cholestatic injury
Diagnosis requires medical evaluation.
You cannot determine the injury pattern from symptoms alone.
How Soon Can Ashwagandha Liver Injury Occur?
Many reported cases developed after:
weeks of exposure.
But there is no guaranteed latency period.
A 2024 case report described a healthy 22-year-old woman who developed:
- Severe itching
- Fatigue
- Nausea
- Jaundice
after taking ashwagandha.
View the case report on PubMed
Case reports cannot establish how commonly an adverse effect occurs.
But they can identify:
potential safety signals.
Does Ashwagandha Damage Everyone’s Liver?
No.
That would be inconsistent with clinical-trial evidence.
The 2026 systematic review of standardized root extract found no clinically meaningful liver abnormalities in more than:
2,300 trial participants.
So the evidence currently suggests:
- Most studied healthy adults tolerate standardized root extract
- Rare idiosyncratic liver injury can still occur
Those statements are not contradictory.
Why Can Trials Look Safe While Case Reports Find Liver Injury?
Because rare adverse events may be too uncommon to appear in relatively small randomized trials.
For example:
If a reaction occurred in:
1 out of tens of thousands
a clinical trial involving a few hundred participants could easily miss it.
This is why supplement safety evaluation needs both:
- Controlled trials
- Post-market reports
Does the Type of Ashwagandha Matter?
Possibly.
The 2026 safety review specifically focused on:
standardized root-only extracts.
Some liver injury reports involve:
- Non-standardized products
- Root-and-leaf extracts
- Multi-ingredient formulations
That creates uncertainty about whether risk comes from:
- Ashwagandha itself
- Specific plant parts
- Extract concentration
- Contamination
- Other ingredients
- Individual susceptibility
Does Root-Only Ashwagandha Appear Safer?
Current data are more reassuring for:
standardized root-only extracts
because they have a larger controlled safety dataset.
That does not prove they are:
risk-free.
Warning Signs of Possible Liver Injury
Stop using the supplement and seek appropriate medical evaluation if you develop:
- Yellow skin
- Yellow eyes
- Dark urine
- Severe generalized itching
- Pale stools
- Persistent nausea
- Unusual fatigue
- Right-upper abdominal pain
especially if symptoms appear after starting:
ashwagandha or another supplement.
Should You Get Liver Tests Before Taking Ashwagandha?
Routine liver testing is not necessarily required for every healthy adult taking a standard supplement.
But extra caution may be appropriate if you:
- Already have liver disease
- Have previously had drug-induced liver injury
- Take medications affecting the liver
- Use multiple supplements
- Drink substantial amounts of alcohol
Discuss individual risk with a healthcare professional.
Can People With Liver Disease Take Ashwagandha?
This requires caution.
Current evidence is not strong enough to say that ashwagandha is universally safe in people with:
existing liver disease.
Given the published hepatotoxicity signal, unsupervised use is difficult to justify in people with:
- Cirrhosis
- Active hepatitis
- Significant liver-enzyme abnormalities
- Previous supplement-related liver injury
Ashwagandha and Thyroid Function
This is another important safety issue.
Ashwagandha may affect:
thyroid hormones.
What Does the Human Trial Show?
A randomized placebo-controlled trial included:
50 adults
with subclinical hypothyroidism.
Participants received:
600 mg/day of ashwagandha root extract
or placebo for:
8 weeks.
Ashwagandha significantly changed:
- TSH
- T3
- T4
compared with placebo.
Does Ashwagandha Increase Thyroid Hormones?
The study suggests that ashwagandha can:
alter thyroid physiology.
That is clinically relevant.
But this should not be interpreted as:
“Ashwagandha is a natural thyroid medication.”
It is not an established substitute for:
- Levothyroxine
- Thyroid monitoring
- Medical treatment
Can Ashwagandha Cause Hyperthyroidism?
There have been case reports suggesting possible:
thyrotoxicosis
or excessive thyroid-hormone effects associated with ashwagandha.
The overall risk is not well quantified.
But because human trial evidence shows thyroid markers can change, people with thyroid disease deserve:
extra caution.
Ashwagandha and Levothyroxine
If you take thyroid hormone medication such as:
levothyroxine,
adding a supplement capable of altering thyroid markers could theoretically complicate:
- TSH control
- Dose requirements
- Symptoms
This combination should not be treated casually.
Should People With Hashimoto’s Take Ashwagandha?
Hashimoto’s disease involves:
autoimmune thyroid disease.
Ashwagandha may affect both:
- Thyroid physiology
- Immune signaling
That makes self-treatment particularly difficult to justify.
Discuss supplementation with the clinician managing your thyroid disease.
What About Graves’ Disease?
Graves’ disease causes:
hyperthyroidism.
Because ashwagandha may influence thyroid hormones, unsupervised use is especially inappropriate.
Ashwagandha and Pregnancy
This area has become more complicated in 2026.
Historically, major U.S. sources including NCCIH have advised avoiding ashwagandha during:
pregnancy.
Concerns have included historical reports suggesting possible:
abortifacient effects.
However, recent research has challenged how strong that historical evidence actually is.
What Does the 2026 Pregnancy Research Show?
A 2026 randomized open-label study included:
70 women in their second trimester.
Participants received either:
- Standard prenatal hematinic care
- Standard care plus ashwagandha root extract at 300 mg twice daily
for:
12 weeks.
No adverse events or serious adverse events were reported, and monitored:
- Liver
- Kidney
- Cardiac
- Thyroid
markers remained stable.
That is important new evidence.
But one study involving:
70 women
does not establish universal pregnancy safety.
What Does the New Reproductive-Safety Review Say?
A 2026 systematic and ethnobotanical review examined historical concerns that ashwagandha could be:
- Teratogenic
- Abortifacient
The authors concluded that some historical warnings appear to rely on weak or repeatedly cited secondary sources and that strong evidence demonstrating an abortifacient effect remains:
inconclusive.
So Is Ashwagandha Safe During Pregnancy?
The scientifically cautious answer is:
we still do not have enough evidence to recommend routine self-supplementation during pregnancy.
Why?
Because:
- Controlled pregnancy data remain very limited
- One recent trial does not establish rare-risk safety
- Pregnancy safety requires a much higher evidence standard
- Product formulations vary
Therefore, pregnancy is not the setting for casually starting:
an herbal supplement without prenatal medical guidance.
Why Doesn’t Celnovix Simply Say “Never Use It During Pregnancy”?
Because the evidence is evolving.
Older blanket warnings deserve to be interpreted alongside:
- The newer pregnancy trial
- Updated reproductive-safety review
But evolving evidence does not equal:
proof of safety.
So the responsible recommendation remains:
Do not introduce ashwagandha during pregnancy without discussing it with the clinician responsible for your prenatal care.
What About Breastfeeding?
There remains insufficient high-quality evidence about:
- Transfer into breast milk
- Infant exposure
- Infant safety
Major U.S. safety guidance therefore continues to recommend avoiding unsupervised ashwagandha use during:
breastfeeding.
Ashwagandha and Autoimmune Disease
Ashwagandha is sometimes described as having:
immune-modulating effects.
That creates theoretical concerns for people with autoimmune disorders.
Examples include:
- Rheumatoid arthritis
- Lupus
- Multiple sclerosis
- Autoimmune thyroid disease
The exact clinical relevance is not well established.
But people taking:
immunosuppressive medication
should be particularly cautious.
Does Ashwagandha Boost the Immune System?
This phrase is overly simplistic.
The immune system is not a:
volume knob
that should always be turned upward.
Ashwagandha may influence:
immune signaling.
That is different from simply:
boosting immunity.
Ashwagandha Drug Interactions
Drug-interaction evidence is less developed than many online interaction lists imply.
Some interactions are:
theoretical or mechanistically plausible
rather than proven by large human interaction trials.
That distinction matters.
Medications That Deserve Extra Caution
Major authoritative sources identify possible interactions involving:
- Sedatives
- Anti-seizure medications
- Thyroid medications
- Diabetes medications
- Blood-pressure medications
- Immunosuppressants
Ashwagandha and Sedatives
Because ashwagandha can cause:
drowsiness,
combining it with medications that depress the central nervous system could theoretically increase:
- Sedation
- Slowed reaction time
- Impaired alertness
Examples may include certain:
- Sleep medications
- Anxiety medications
- Sedating antihistamines
Medication-specific risk should be reviewed with a pharmacist or clinician.
Ashwagandha and Anti-Seizure Medication
NCCIH includes anticonvulsants among medication classes with potential:
interaction concerns.
People with epilepsy or seizure disorders should not change medication or add supplements without appropriate clinical review.
Ashwagandha and Blood-Pressure Medication
Ashwagandha may influence:
blood pressure.
Combining it with antihypertensive medication could theoretically contribute to:
excessive blood-pressure reduction
in some people.
Evidence is not strong enough to predict the effect reliably.
Ashwagandha and Diabetes Medication
Ashwagandha may influence:
glucose metabolism.
This raises concern that combining it with glucose-lowering medications could contribute to unexpectedly low:
blood glucose.
Again, the exact interaction risk is not well quantified.
Ashwagandha and Immunosuppressants
Because ashwagandha may affect immune signaling, it may theoretically oppose or alter the effects of:
immunosuppressive therapy.
This is especially relevant for people with:
- Autoimmune disease
- Organ transplants
- Other conditions requiring immune suppression
Ashwagandha and Thyroid Medication
This is one of the more biologically plausible interactions because human clinical data show ashwagandha can alter:
- TSH
- T3
- T4
Taking it alongside thyroid hormone medication should therefore be approached carefully.
Ashwagandha and Antidepressants
Evidence for specific antidepressant interactions is limited.
Do not assume that ashwagandha is:
- Always safe with antidepressants
- A replacement for antidepressant therapy
If you take psychiatric medication, discuss supplements with the prescribing professional.
Ashwagandha and Alcohol
Alcohol may increase:
- Sedation
- Impaired judgment
- Sleep disruption
Ashwagandha can also produce drowsiness in some users.
There is not enough evidence to define a universally safe combination threshold.
Ashwagandha Before Surgery
NCCIH advises against ashwagandha use in people who are:
about to have surgery.
Potential concerns include effects involving:
- Sedation
- Blood pressure
- Glucose
- Thyroid function
- Medication interactions
Always disclose herbal supplements to:
- Surgeon
- Anesthesiologist
- Preoperative medical team
Does Ashwagandha Affect Testosterone?
Some studies have reported changes in:
testosterone.
Effects are not consistent across all populations.
NCCIH notes concern about ashwagandha in people with:
hormone-sensitive prostate cancer.
That is another reason why “natural testosterone booster” marketing is overly simplistic.
Can Women Take Ashwagandha?
Generally:
yes, many women do.
Sex alone is not a reason to avoid ashwagandha.
The more relevant questions are whether someone:
- Is pregnant
- Is breastfeeding
- Has thyroid disease
- Has liver disease
- Uses interacting medications
Can Men Take Ashwagandha?
Yes, many men do.
But people with:
hormone-sensitive prostate cancer
should discuss it with their oncology team because of potential androgen-related concerns.
Does Ashwagandha Affect Hormones?
Potentially.
Human studies have explored effects involving:
- Cortisol
- Thyroid hormones
- Testosterone
This is why describing ashwagandha as a completely neutral:
stress herb
can understate its biological activity.
Long-Term Ashwagandha Safety
This remains one of the biggest evidence gaps.
Short-term and medium-term data are considerably stronger than:
multi-year data.
How Long Has Ashwagandha Been Studied?
The 2026 standardized-root systematic review included interventions up to:
180 days.
That is approximately:
six months.
Most trials are shorter.
Is Ashwagandha Safe for Years?
We do not currently have enough high-quality randomized evidence to say:
yes.
This does not mean long-term use has been proven dangerous.
It means:
the evidence is insufficient.
Should You Cycle Ashwagandha?
There is no established evidence-based protocol such as:
- 8 weeks on / 2 weeks off
- 12 weeks on / 4 weeks off
that has been shown to improve:
- Safety
- Effectiveness
- Tolerance
Cycling practices are largely:
empirical rather than clinically validated.
Can Ashwagandha Cause Withdrawal?
There is no well-established:
ashwagandha withdrawal syndrome.
But systematic human research on discontinuation remains limited.
Can You Become Dependent on Ashwagandha?
There is currently no good evidence that ashwagandha causes:
drug-like physical dependence.
However, psychological reliance on any supplement routine is possible.
Does Ashwagandha Stop Working Over Time?
There is insufficient evidence to conclude that users inevitably develop:
tolerance.
Do not automatically increase the dose because you believe the product has:
stopped working.
Does Higher Dose Mean More Side Effects?
Potentially.
In pharmacology, greater exposure can increase:
- Side effects
- Interaction risk
But ashwagandha products differ so much that simple milligram comparisons can be misleading.
Why 600 mg Is Not Always 600 mg
A product may contain:
600 mg raw root powder
while another contains:
600 mg concentrated extract
These are not necessarily equivalent.
Other variables include:
- Root vs leaf
- Extraction ratio
- Withanolide concentration
- Manufacturing quality
What Are Withanolides?
Withanolides are bioactive steroidal lactones naturally found in:
Withania somnifera.
Many standardized extracts list their:
withanolide content.
But more withanolides do not automatically mean:
- Better
- Faster
- Safer
Clinical evidence is:
formulation-specific.
Does Ashwagandha Affect Kidney Function?
The 2026 standardized-root systematic review did not find clinically meaningful kidney-function abnormalities in healthy trial participants.
That is reassuring.
But people with:
significant kidney disease
were not necessarily well represented.
So absence of a signal in healthy adults should not be interpreted as proof of safety in:
advanced kidney disease.
Can Ashwagandha Cause Allergic Reactions?
Hypersensitivity reactions are possible with botanical products.
Seek urgent care for:
- Difficulty breathing
- Facial swelling
- Throat swelling
- Severe widespread rash
Is Ashwagandha Safe With Magnesium?
There is no well-established major interaction between:
ashwagandha and ordinary dietary magnesium.
However, individual products and health conditions matter.
Read:
Ashwagandha and Magnesium: Can You Take Them Together?
Does Ashwagandha Make You Feel Emotionally Numb?
Some users online describe:
- Emotional blunting
- Reduced motivation
- Apathy
These experiences have not been well characterized in randomized clinical trials.
So they should be treated as:
anecdotal signals rather than established common side effects.
If a supplement consistently makes you feel worse psychologically, continuing it simply because an online source says this means it is:
“working”
is not sensible.
Can Ashwagandha Cause Anxiety?
Ashwagandha is more often studied for:
stress and anxiety reduction.
But individual reactions can differ.
If you experience:
- Agitation
- Palpitations
- Worsening anxiety
- Insomnia
after starting a product, reassess its use.
Can Ashwagandha Cause Heart Palpitations?
Palpitations require context.
Possible causes include:
- Anxiety
- Caffeine
- Thyroid changes
- Medications
- Cardiac rhythm disorders
Because ashwagandha can affect thyroid physiology in some people, persistent palpitations should not simply be ignored.
Can Ashwagandha Cause Weight Gain?
Weight gain is not established as a common direct adverse effect.
Body weight can change for many reasons.
Do not automatically attribute weight change to:
ashwagandha.
Can Ashwagandha Cause Weight Loss?
Likewise, ashwagandha is not an established:
weight-loss drug.
Does Ashwagandha Affect Fertility?
Research has explored male fertility and reproductive hormones.
But ashwagandha should not be considered an established:
fertility treatment.
Reproductive-safety evidence remains incomplete.
How Do You Know If a Side Effect Is From Ashwagandha?
This can be difficult.
Ask:
Timing
Did the symptom begin after starting the supplement?
Dechallenge
Does it improve after stopping?
Other Causes
Did anything else change?
- Medication
- Diet
- Alcohol
- Illness
- Other supplements
Rechallenge
Deliberately restarting a supplement after a serious suspected adverse reaction is generally:
not a good self-experiment.
Especially if the suspected reaction involved:
- Liver injury
- Allergy
- Severe endocrine symptoms
When Should You Stop Taking Ashwagandha?
Consider stopping and seeking medical advice for:
- Yellow skin or eyes
- Dark urine
- Severe itching
- Persistent vomiting
- Severe abdominal pain
- Significant allergic symptoms
- Severe drowsiness
- New palpitations
- Major thyroid-like symptoms
For mild GI symptoms, stopping or changing the product may also be appropriate.
When Is a Side Effect an Emergency?
Seek urgent medical care for:
- Difficulty breathing
- Severe facial or throat swelling
- Fainting
- Severe chest pain
- Confusion
- Signs of significant liver injury
Who Should Avoid Self-Supplementing With Ashwagandha?
Particular caution is appropriate for people who:
- Are pregnant
- Are breastfeeding
- Have thyroid disorders
- Have liver disease
- Have significant autoimmune disease
- Have hormone-sensitive prostate cancer
- Use multiple prescription medications
- Are preparing for surgery
What Do U.S. Health Authorities Say?
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.
It also notes potential concerns involving:
- Liver injury
- Thyroid function
- Pregnancy
- Breastfeeding
- Surgery
- Autoimmune disease
- Medication interactions
View NCCIH Ashwagandha Safety Information
The NIH Office of Dietary Supplements provides similar guidance.
View NIH Office of Dietary Supplements Ashwagandha Fact Sheet
Why Does the NIH Say Three Months While a 2026 Review Includes Six Months?
Because authoritative public-health guidance can be more conservative than:
the longest available individual trial.
The 2026 review found standardized root extract generally well tolerated in studies up to:
180 days.
But the broader evidence base is still dominated by:
short-term studies.
So both statements can be true:
- Some controlled studies extend to six months.
- Long-term safety remains insufficiently established.
Ashwagandha Safety by Population
|
Population |
Current Evidence |
|---|---|
|
Healthy adults, short term |
Generally well tolerated |
|
Use up to 3 months |
Relatively well studied |
|
3–6 months |
Some supportive data |
|
Multi-year use |
Insufficient evidence |
|
Liver disease |
Extra caution |
|
Thyroid disease |
Extra caution |
|
Pregnancy |
Emerging data, still insufficient for routine self-use |
|
Breastfeeding |
Insufficient evidence |
|
Autoimmune disease |
Potential concern |
|
Polypharmacy |
Interaction review advised |
Ashwagandha Side Effects Evidence Scorecard
|
Safety Question |
Evidence |
|---|---|
|
Mild GI symptoms |
Supported |
|
Drowsiness |
Supported |
|
Headache |
Reported |
|
Rare liver injury |
Supported by case reports/series |
|
Universal liver toxicity |
Not supported |
|
Thyroid effects |
Human evidence exists |
|
Long-term multi-year safety |
Unknown |
|
Pregnancy harm |
Not clearly established |
|
Pregnancy safety |
Not established sufficiently |
|
Drug interactions |
Plausible; direct evidence limited |
|
Withdrawal syndrome |
Not established |
|
Need to cycle |
Not established |
The Most Important Safety Distinction
The correct interpretation of the evidence is:
Clinical trials tell us:
Standardized root-only ashwagandha is generally well tolerated by healthy adults over the durations studied.
Case reports tell us:
Rare but potentially serious reactions such as:
liver injury
can occur.
Endocrine trials tell us:
Ashwagandha can affect:
thyroid physiology.
Public-health guidance tells us:
Certain populations deserve:
extra caution.
All four pieces matter.
The Bottom Line
What are the side effects of ashwagandha?
For many healthy adults, the most likely adverse effects are relatively mild:
- Stomach upset
- Loose stools
- Nausea
- Drowsiness
- Headache
A 2026 systematic review of:
23 studies
and:
2,317 healthy adults
found standardized root extract generally well tolerated at:
125–600 mg/day
for up to:
180 days.
But that does not make ashwagandha universally safe.
Rare cases of:
clinically significant liver injury
have been documented.
Ashwagandha can also alter:
thyroid hormones
and may interact with several medication classes.
Long-term multi-year safety remains:
uncertain.
So the most evidence-aligned position is:
Ashwagandha appears reasonably well tolerated for many healthy adults during short-term use, but it is a biologically active supplement with meaningful safety considerations.
Treat it like a:
real intervention
rather than harmless herbal tea.
Frequently Asked Questions
What are the most common side effects of ashwagandha?
Commonly reported mild effects include stomach upset, nausea, loose stools, drowsiness and occasional headache.
Is ashwagandha safe?
Short-term standardized root extract appears generally well tolerated in healthy adults, but long-term safety is not fully established.
Can ashwagandha hurt your liver?
Rare cases of liver injury have been reported. The overall risk appears low but is not zero.
What are the signs of ashwagandha liver injury?
Possible warning signs include jaundice, dark urine, severe itching, pale stools, nausea and unusual fatigue.
Is ashwagandha bad for the thyroid?
It may alter thyroid hormones. People with thyroid disorders or taking thyroid medication should be cautious.
Can ashwagandha cause hyperthyroidism?
Case reports and thyroid data suggest this may be possible in susceptible individuals, although the risk is not well quantified.
Can you take ashwagandha with levothyroxine?
Because ashwagandha can influence thyroid markers, this combination should be reviewed with the clinician managing your thyroid medication.
Is ashwagandha safe during pregnancy?
New 2026 evidence is more reassuring than older blanket warnings, but pregnancy safety remains insufficiently established for routine unsupervised use.
Can you take ashwagandha while breastfeeding?
There is insufficient high-quality evidence. Major U.S. guidance advises against unsupervised use.
Can ashwagandha cause diarrhea?
Yes. Loose stools and GI discomfort are among the more commonly reported mild adverse effects.
Can ashwagandha cause nausea?
Yes.
Can ashwagandha cause drowsiness?
Yes, some people experience temporary drowsiness.
Can ashwagandha cause headaches?
Headaches have occasionally been reported.
Can ashwagandha cause anxiety?
It is generally studied for stress reduction, but individual reactions vary. Stop and reassess if symptoms worsen.
Can ashwagandha cause heart palpitations?
Palpitations are not established as a common side effect, but possible thyroid effects make persistent palpitations worth evaluating.
Can you take ashwagandha every day?
Daily use is common in clinical trials, but long-term multi-year daily safety remains insufficiently studied.
How long is ashwagandha safe to take?
Most evidence is short term. A 2026 review included standardized root-extract studies lasting up to 180 days, but longer-term evidence remains limited.
Should you cycle ashwagandha?
No evidence-based cycling protocol has been established.
Does ashwagandha interact with medications?
Potential interactions include thyroid medication, sedatives, anticonvulsants, diabetes medications, antihypertensives and immunosuppressants.
Should I stop ashwagandha before surgery?
Major U.S. complementary-health guidance advises avoiding it around surgery. Inform your surgical and anesthesia teams about all supplements.
Related Celnovix Guides
- What Is Ashwagandha?
- How Long Does Ashwagandha Take to Work?
- Best Time to Take Ashwagandha: Morning or Night?
- How Long Does Ashwagandha Stay in Your System?
- Ashwagandha and Magnesium: Can You Take Them Together?
References
Coope OC, et al.
Back to the Roots: Safety and Tolerability of Standardised Ashwagandha Root Extract in Healthy Adults
Published in 2026, this systematic review included:
23 studies
and:
2,317 participants.
Standardized root-only extracts were used at approximately:
125–600 mg/day
for periods up to:
180 days.
No serious adverse events attributable to standardized root extract were reported in the included trials.
Mild adverse events included:
- GI discomfort
- Headache
- Temporary drowsiness
The authors emphasized that long-term data beyond 180 days remain limited.
Several authors disclosed consulting, speaking or employment relationships involving the dietary-supplement industry.
Ashwagandha-Associated Liver Injury: A Scoping Review
Published in 2026, this review identified:
25 reported patients
across:
13 publications.
Liver injury generally occurred after weeks of use.
The most frequent patterns were:
- Cholestatic
- Mixed liver injury
with symptoms commonly including:
- Jaundice
- Pruritus
Case reports cannot determine incidence, but they establish a clinically relevant:
rare safety signal.
Sharma AK, et al.
Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients
This randomized placebo-controlled trial included:
50 adults
and tested:
600 mg/day
of root extract for:
8 weeks.
Ashwagandha significantly changed:
- TSH
- T3
- T4
compared with placebo.
These findings help explain why people with thyroid disorders should approach supplementation carefully.
Ajgaonkar A, et al.
Efficacy and Safety of Ashwagandha Root Extract in Pregnant Women
Published in 2026, this prospective randomized open-label study included:
70 second-trimester pregnant women.
Participants received standard prenatal care with or without:
300 mg ashwagandha root extract twice daily
for:
12 weeks.
No adverse events or serious adverse events occurred, and monitored organ-function markers remained stable.
The study is noteworthy but too small and short to establish universal pregnancy safety.
Tallon MJ, et al.
A Systematic and Ethnobotanical Review of Ashwagandha’s Teratogenic and Abortifacient Potentials
This recent review re-examined historical claims that ashwagandha is inherently:
- Teratogenic
- Abortifacient
The authors concluded that evidence supporting major reproductive toxicity remains inconclusive and that some historical claims may have been propagated without adequate primary-source validation.
This does not establish pregnancy safety; it highlights uncertainty in the older evidence base.
U.S. National Center for Complementary and Integrative Health
NCCIH notes that short-term ashwagandha use may be reasonably well tolerated but highlights concerns involving:
- Liver injury
- Thyroid function
- Pregnancy
- Breastfeeding
- Autoimmune disorders
- Surgery
- Medication interactions
View NCCIH Ashwagandha Guidance
NIH Office of Dietary Supplements
The NIH Office of Dietary Supplements similarly notes that short-term clinical studies generally report mild adverse effects, while long-term safety remains uncertain.
Potential interaction concerns include:
- Diabetes medications
- Blood-pressure medications
- Immunosuppressants
- Sedatives
- Thyroid medications
View the NIH Professional Fact Sheet
Evidence Transparency
Important limitations include:
- Ashwagandha formulations differ substantially.
- Root-only and root-plus-leaf extracts should not automatically be treated as equivalent.
- Most randomized trials are relatively short.
- Healthy volunteers do not represent all clinical populations.
- Rare adverse events may not appear in randomized trials.
- Liver-injury reports cannot determine population incidence.
- Drug-interaction evidence often relies on mechanism rather than dedicated interaction trials.
- Pregnancy evidence remains very limited despite newer studies.
- Long-term multi-year safety has not been established.
Editorial Standards
Celnovix distinguishes between:
- Common adverse events
- Rare safety signals
- Case reports
- Randomized clinical safety data
- Mechanistic drug interactions
- Confirmed clinical interactions
- Absence of evidence
- Evidence of absence
We do not interpret:
- Short-term tolerability as lifelong safety
- A liver case report as proof that everyone is at risk
- No liver injury in small trials as proof that rare hepatotoxicity cannot occur
- Thyroid-marker changes as proof that ashwagandha should treat thyroid disease
- One pregnancy trial as proof of universal pregnancy safety
- “Natural” as synonymous with “harmless”
Medical Disclaimer
This article is provided for general educational and informational purposes only and does not constitute medical advice, diagnosis, treatment or individualized supplement guidance.
Ashwagandha is a biologically active botanical and may not be appropriate for everyone.
Discuss its use with an appropriately qualified healthcare professional if you:
- Take prescription medication
- Have thyroid disease
- Have liver disease
- Have autoimmune disease
- Are pregnant or breastfeeding
- Are preparing for surgery
- Have other significant medical conditions
Seek prompt medical care for symptoms suggesting liver injury, a severe allergic reaction or other serious adverse effects.
