Ashwagandha has earned its place as one of the most popular adaptogenic herbs on the market, with millions of people turning to it for stress relief, improved sleep, and enhanced performance. But as its popularity has surged, so has a critical question that often gets buried beneath the marketing: what are the actual ashwagandha side effects, and how significant are they?
The honest answer is more nuanced than either enthusiastic supplement advocates or cautious skeptics tend to admit. Some reported side effects are well-documented and worth taking seriously. Others are overstated, poorly understood, or based on isolated case reports that lack broader scientific context.
In this analysis, we cut through the noise and examine what peer-reviewed research actually reveals about ashwagandha’s safety profile. You will learn which side effects appear consistently in clinical trials, which populations face the greatest risk, how dosage and duration factor into the equation, and what warning signs should prompt you to stop taking it. If you are already using ashwagandha or considering it, this is the information you need to make a genuinely informed decision.
What Ashwagandha Is and Why People Take It
Ashwagandha (Withania somnifera) is an evergreen shrub native to India, Africa, and parts of the Middle East that has functioned as a cornerstone of Ayurvedic medicine for thousands of years. Within that tradition, it is classified as an adaptogen, a category of botanicals believed to help the body mount a more balanced response to physical and psychological stress. The plant’s active compounds, including a class of steroidal lactones known as withanolides, are thought to modulate the body’s cortisol response, which is the primary hormonal mechanism behind the adaptogen theory. According to Cleveland Clinic’s analysis of the supplement, consumer interest has surged alongside mainstream wellness culture, with the herb now drawing attention well beyond its traditional Ayurvedic context.
Commercially, ashwagandha products are derived almost exclusively from the plant’s root and are sold in an expanding range of formats, including capsules, gummies, liquid drops, and powders. Marketing claims tend to cluster around stress relief, sleep improvement, energy, and cognitive support, making it one of the most versatile positioning stories in the supplement industry. That breadth of claimed benefits is part of what drives its appeal, but it also invites scrutiny. The NIH Office of Dietary Supplements maintains an active professional fact sheet on the supplement, underscoring that institutional health authorities consider it a topic worth monitoring carefully.
The evidence picture is more nuanced than most product labels suggest. The National Center for Complementary and Integrative Health (NCCIH) has stated that some ashwagandha preparations may be effective for insomnia and stress, but adds a pointed caveat: evidence is unclear about its effects on anxiety. That distinction matters considerably, because anxiety relief is one of the supplement’s most prominent marketing claims. The World Federation of Societies of Biological Psychiatry and the Canadian Network for Mood and Anxiety Treatments have both provisionally recommended ashwagandha for generalized anxiety disorder, yet those recommendations rest on limited and inconsistent evidence drawn from small, methodologically varied trials. A 2025 review published in Nutrients reflects the ongoing effort to synthesize what is known about the herb’s effects on well-being, but the research base remains heterogeneous in dosage, formulation, and outcome measures.
Ashwagandha is nonetheless having a pronounced cultural moment. Northeastern University researchers published new findings on potential benefits in January 2026, and industry analysts have consistently tracked the herb as a standout leader within the broader adaptogen market surge that has accelerated through mainstream retail and social media channels. That rising profile makes an honest, clinically grounded assessment of its side effects not just useful but genuinely necessary for anyone considering it as part of a health regimen.
The Most Common Side Effects of Ashwagandha
Gastrointestinal complaints consistently rank as the most frequently reported side effects of ashwagandha supplementation. Nausea, diarrhea, stomach cramping, and vomiting appear across multiple clinical trials and case reports, with higher doses correlating with greater GI distress. The 2023 narrative review published in Pharmaceutics documents these adverse effects within a rigorous pharmacological framework, offering a credible scientific foundation that goes well beyond manufacturer safety labels. The 2025 review published in Nutrients similarly catalogs these GI effects as part of a broader well-being analysis, reinforcing that the complaint pattern is reproducible across independent research teams rather than confined to a single study cohort.
Drowsiness and sedation represent a second well-documented category of concern. These effects are thought to be mechanistically linked to ashwagandha’s activity on the GABAergic system, the same neural pathway targeted by benzodiazepines and certain anticonvulsants. This is clinically significant because ashwagandha can compound the sedating effects of alcohol, prescription sleep aids, and other CNS depressants, sometimes substantially. Anyone taking medications in these categories should treat this interaction as a genuine pharmacological consideration rather than a theoretical caution, and a conversation with a prescribing physician before adding the supplement is appropriate.
A third cluster of effects, including headache, dizziness, and nasal congestion, appears in some clinical trial participant reports and is generally mild in severity. These symptoms tend to emerge during the first few weeks of use and often resolve on their own, but they are worth monitoring and documenting, particularly for anyone managing other health conditions.
Interpreting all of these findings requires an important caveat. As WebMD notes in its comprehensive supplement profile, and as the Cleveland Clinic has emphasized, studies on ashwagandha have used widely inconsistent dosages and formulations across relatively small participant populations. That methodological variability makes it genuinely difficult to determine whether the GI and neurological side effects described above are dose-dependent responses that worsen predictably with higher intake, or idiosyncratic reactions tied to specific extract types or individual physiology. Until larger, standardized trials close that gap, the honest clinical position is that these effects are real and documented but incompletely characterized.
The Most Serious Risk: Ashwagandha and Liver Injury
Beyond the gastrointestinal complaints covered earlier, a far more serious concern has emerged in the clinical literature: ashwagandha’s documented capacity to cause liver injury. The NIH’s LiverTox database, maintained by the National Institute of Diabetes and Digestive and Kidney Diseases, formally flags ashwagandha as implicated in clinically apparent hepatotoxicity, noting that while controlled trials have not consistently reported enzyme elevations, real-world case reports have significantly changed the safety picture. This is not a theoretical risk confined to obscure formulations or unusual doses; it has been observed with commercially available products at standard supplemental amounts.
What the Case Evidence Shows
The medical literature now includes documented cases of ashwagandha-associated liver injury from India, Iceland, the United States, the Netherlands, Poland, and Australia, confirming this is a global pattern rather than an isolated phenomenon. A landmark case series involving the U.S. Drug-Induced Liver Injury Network identified five otherwise healthy individuals who developed jaundice after using ashwagandha, with injury characterized as cholestatic or mixed-pattern hepatitis. Onset occurred within 2 to 12 weeks of beginning supplementation, and liver tests normalized within 1 to 5 months in four of the five patients following discontinuation. A 2023 case report published in the International Journal of Environmental Research and Public Health documented the same clinical trajectory in an otherwise healthy individual using a commercially available ashwagandha product, further reinforcing that injury is not limited to high-dose or prolonged use.
Recognizing the Warning Signs
Symptoms associated with ashwagandha-related liver injury include jaundice (yellowing of the skin or eyes), dark urine, severe fatigue, right upper abdominal discomfort, itching, and loss of appetite. Most cases resolved after stopping the supplement, but jaundice and elevated bilirubin in some patients persisted for 5 to 20 weeks, indicating the recovery process can be prolonged.
Why the Mechanism Matters
Part of what makes this risk particularly difficult to navigate is that the underlying mechanism remains poorly understood. Ashwagandha contains more than 100 chemical constituents, including withanolides, alkaloids, and saponins, and the specific compound responsible for hepatotoxicity has not been identified. Critically, injury does not appear to follow a straightforward dose-response relationship; cases have been reported across a wide range of doses and durations, meaning there is currently no established “safe” threshold that consumers can rely on. This unpredictability distinguishes ashwagandha hepatotoxicity from many other supplement-related risks where limiting dose offers meaningful protection.
For individuals already undergoing regular metabolic monitoring, such as those enrolled in a physician-supervised program that includes quarterly laboratory work, early signals of liver stress such as rising transaminase levels can be identified before symptoms develop. Those self-supplementing without any clinical oversight lack that safety net entirely, which represents a meaningful and underappreciated gap between supervised and unsupervised supplement use.
The Thyroid Hormone Problem Most Articles Miss
Ashwagandha’s influence on thyroid physiology is one of the most clinically significant and consistently underreported aspects of this supplement. Research has documented that ashwagandha root extract is pharmacologically active on the hypothalamic-pituitary-thyroid (HPT) axis, with studies demonstrating measurable increases in serum T3 (triiodothyronine), T4 (thyroxine), and alterations in thyroid-stimulating hormone (TSH). This is not a passive or theoretical interaction; the supplement actively engages the hormonal feedback loop that governs thyroid output, which carries direct consequences for anyone whose thyroid function is already being managed medically.
The most acute risk involves patients taking levothyroxine or other thyroid hormone replacement medications. When someone is stabilized on a levothyroxine dose, their physician has calibrated that prescription against a specific hormonal baseline. Adding ashwagandha can push total circulating thyroid hormone levels beyond that calibrated range, effectively creating a hyperthyroid state even when the prescription dose has not changed. The resulting symptoms, including palpitations, anxiety, insomnia, and unexplained weight changes, can easily be misattributed to other causes rather than recognized as supplement-driven hormonal overcorrection.
A published case report in a peer-reviewed journal on ashwagandha-induced thyrotoxicosis illustrates precisely how serious this can become. A 73-year-old patient who self-administered ashwagandha root extract over two years presented with supraventricular tachycardia and biochemical thyrotoxicosis. Symptoms resolved fully after the supplement was discontinued. The authors noted that this adverse effect is “rarely reported in the literature,” confirming that the content gap exists not only in consumer wellness articles but within the medical publishing record itself.
For individuals with autoimmune thyroid conditions, the risk profile becomes even less predictable. Ashwagandha’s immunomodulatory properties, often marketed as a benefit, can be counterproductive in conditions like Hashimoto’s thyroiditis or Graves’ disease, where immune activity is already dysregulated. Stimulating immune function in these contexts may aggravate the autoimmune process rather than support recovery.
There is also a critical laboratory interpretation problem that the levothyroxine and ashwagandha interaction reviewed by Ubie Health identifies clearly: ashwagandha use can skew thyroid panel results in ways that confound clinical decision-making. A patient could present with an abnormal TSH or T4 reading, and neither the patient nor the ordering physician may connect it to supplement use. This is a particularly significant concern for anyone whose metabolic health is being actively tracked through periodic lab work, since a misread panel can lead to unnecessary medication adjustments.
Anyone with a diagnosed thyroid condition or a current thyroid medication prescription should disclose all active supplement use to their physician before a thyroid panel is drawn, and should seek clinical guidance before adding ashwagandha to their regimen.
Who Should Not Take Ashwagandha
The populations most at risk from ashwagandha are not randomly distributed. They share a common thread: a pre-existing physiological condition or concurrent medication that transforms an otherwise tolerable supplement into a genuine clinical hazard. Understanding exactly who falls into these categories is essential before starting supplementation.
Pregnant individuals should avoid ashwagandha entirely. In traditional Ayurvedic practice, the herb has historically been used as an abortifacient, meaning its capacity to stimulate uterine contractions is not a theoretical concern but a documented pharmacological property embedded in its centuries-long use. Current clinical guidance from the NCCIH explicitly advises against ashwagandha use during pregnancy, citing the risk of uterine contractions and potential fetal harm. Breastfeeding individuals are similarly advised to avoid it, given insufficient safety data for infants.
People living with autoimmune conditions face a distinct and serious risk. Ashwagandha’s immunostimulatory properties are part of what makes it appealing as an adaptogen, but for individuals with rheumatoid arthritis, lupus, multiple sclerosis, or Hashimoto’s thyroiditis, amplifying an already overactive immune response can accelerate disease activity and worsen symptoms. The same mechanism that may support a healthy immune system becomes counterproductive when the immune system is already attacking the body’s own tissue.
Anyone taking sedatives, benzodiazepines, or sleep medications should exercise particular caution. Ashwagandha has intrinsic CNS-depressant properties, and combining it with pharmaceutical sedatives creates an additive effect that can produce excessive drowsiness, impaired motor coordination, and respiratory depression in vulnerable individuals. This interaction is qualitative rather than dose-specific, meaning the risk exists even at commonly used supplemental doses.
Individuals with thyroid disorders or those taking thyroid medications face direct pharmacological interference, as covered in the previous section. Ashwagandha measurably alters thyroid hormone levels, which creates a real risk of under- or over-treatment in anyone on levothyroxine or antithyroid agents.
Finally, people with known liver disease or elevated baseline liver enzymes should not take ashwagandha. Given the hepatotoxicity cases documented in the clinical literature, this population has no adequate safety margin. A thorough review of ashwagandha’s serious side effects reinforces that anyone who develops jaundice, abdominal pain, or unusual fatigue while using the supplement should discontinue use and seek medical evaluation without delay. This is not a supplement to self-manage around a compromised liver.
There Is No Approved Safe Dose, and That Matters
The FDA has not approved a standardized dose of ashwagandha, and that regulatory gap has direct consequences for anyone taking it. Clinical trials have used doses ranging from 120 mg to 1,250 mg per day, across root extracts, leaf extracts, root powders, and proprietary trademarked blends such as KSM-66 and Sensoril, each with differing withanolide concentrations. These trials have also varied widely in duration, population, and formulation. The result is a fractured evidence base in which no single dose has been validated as safe, effective, or appropriate across the general population.
The dose printed on a supplement label is chosen by the manufacturer, not established by a regulatory body. A 600 mg capsule carries no greater implicit safety assurance than any other dose that happened to appear in a small, short-duration study. The Operation Supplement Safety program, a U.S. Department of Defense resource, states directly that most ashwagandha studies were small, short-term, and used varying doses and formulations, making it impossible to draw firm conclusions about effectiveness or safety from the existing literature.
Institutional health authorities have reached the same conclusion. The Cleveland Clinic notes that inconsistent dosages and formulations across studies make definitive safety or efficacy conclusions difficult to support. The NCCIH acknowledges that evidence remains unclear on several of ashwagandha’s most commonly marketed effects. The NIH Office of Dietary Supplements treats ashwagandha as a supplement with meaningful unresolved safety questions, particularly regarding liver function.
Long-term safety data is essentially absent. Most clinical trials run for 8 to 12 weeks, and no robust evidence exists for what occurs at 6 months, 1 year, or beyond, particularly in individuals with metabolic conditions, thyroid disorders, or concurrent medication use. A 2025 peer-reviewed paper published in Cureus explicitly identifies long-term human data as a current research gap.
Because no regulatory body has established a tolerable upper intake level, there is no clinical threshold at which consumers are advised to stop. That burden falls entirely on the individual, with no standardized framework to guide the decision.
Can You Take Ashwagandha with GLP-1 Medications Like Semaglutide or Tirzepatide?
As of 2026, no published clinical studies have directly examined the safety or pharmacokinetic interaction between ashwagandha and GLP-1 receptor agonists. Semaglutide and tirzepatide are among the most prescribed medications in the United States, yet the question of whether ashwagandha can be safely combined with either drug remains genuinely unanswered. The absence of a documented contraindication should not be read as clearance. It reflects a gap in the research literature, not a clean bill of safety. This distinction matters considerably for patients who assume that “no warning listed” means “safe to combine.”
Theoretical Interaction Concerns Worth Taking Seriously
Several biologically plausible interaction mechanisms deserve attention, even without direct clinical trial data to confirm or refute them.
Ashwagandha’s documented effects on thyroid hormone levels introduce a meaningful variable for patients on GLP-1 therapy, where metabolic monitoring is already a clinical priority. GLP-1 receptor agonists have their own thyroid-related safety considerations, with the FDA maintaining a warning related to medullary thyroid carcinoma risk based on animal studies. Adding a supplement with independent thyroid-modulating activity creates a monitoring challenge that a care team cannot fully account for unless they know the supplement is being taken.
Ashwagandha’s hepatic activity raises additional questions. As covered earlier in this post, the supplement carries a documented risk of liver injury in susceptible individuals. GLP-1 medications are associated with changes in liver fat and hepatic metabolism over time, making liver enzyme trends a relevant marker to track. A patient taking ashwagandha concurrently without disclosing it introduces a confounding variable into what should be a clear clinical picture.
The sedating properties of ashwagandha present a third concern. Fatigue and nausea are among the most commonly reported side effects during GLP-1 dose titration. If ashwagandha amplifies fatigue through its sedating mechanisms, distinguishing that effect from medication-related side effects becomes difficult, which can complicate decisions about whether to adjust the dose.
Why Disclosure Is Not Optional
GLP-1 therapy is not a static prescription. It involves ongoing dose titration, regular lab monitoring, and side-effect management over months and years. Adding an uncharacterized supplement to that regimen without telling the care team removes information they need to do their job accurately.
Patients enrolled in physician-supervised programs should raise all supplement use, including ashwagandha, during their initial clinical review and at every subsequent check-in. A program that includes quarterly metabolic lab work provides the precise structure needed to detect signals from undisclosed supplement additions: shifts in thyroid markers, liver enzyme elevations, or unexpected changes in fasting glucose. That ongoing visibility is what makes supervised care meaningfully different from managing treatment in isolation.
Why ‘It’s Natural’ Is Not a Safety Argument
The phrase “it’s natural” functions as a rhetorical shield in supplement marketing, and it is one of the most clinically dangerous assumptions a patient can carry into a self-care decision. Arsenic is natural. Hemlock is natural. Belladonna has been cultivated by apothecaries for centuries. Natural origin has never been a reliable proxy for safety, and ashwagandha’s documented adverse effects make this point without ambiguity. The hepatotoxicity cases reported to regulatory bodies, the thyroid hormone disruption covered in earlier sections, and the drug interactions flagged by major clinical institutions are not theoretical concerns constructed by pharmaceutical skeptics. They are the measurable consequences of a bioactive compound doing what bioactive compounds do: producing real physiological effects, some intended, some not.
The structural problem compounds the biological one. In the United States, dietary supplements are not required to demonstrate safety or efficacy before reaching store shelves. Prescription medications must clear a proactive regulatory threshold before a single patient receives them. Supplements clear no such threshold. Harm surfaces only after products are already in consumer hands, which means the entire safety architecture rests on reactive post-market adverse event reporting. Australia’s Therapeutic Goods Administration has issued formal safety alerts on ashwagandha-containing products, noting that liver injury cases “continue to be reported internationally.” That kind of reactive alert is the system working as designed, and it is still not enough.
Public awareness is beginning to catch up. A physician-produced video titled “The Dark Side of Ashwagandha” accumulated over 243,000 views by mid-2025, a figure that reflects genuine consumer appetite for credentialed, risk-forward information rather than the promotional framing that dominates supplement marketing. People are actively seeking honest assessments from clinicians, not reassurance from product labels.
That instinct to seek clinical guidance points toward the most actionable principle in this entire discussion. Patients who disclose supplement use to their physicians receive meaningfully better care: liver enzyme values and thyroid panels are interpreted in the correct context, interactions are identified before they cause harm, and treatment decisions are made with complete information. Yet surveys consistently show that a significant portion of patients do not tell their care teams what supplements they are taking.
The clinical reasoning here mirrors the reasoning behind structured physician oversight for GLP-1 therapy. Any bioactive compound with real physiological effects, a documented interaction profile, and measurable impact on metabolic markers warrants clinical visibility. Removing that visibility by self-supplementing without disclosure does not eliminate the risk; it simply eliminates the safety net.
What to Do If You Are Considering Ashwagandha
Before starting ashwagandha, request a baseline liver panel and thyroid panel from your physician. Specifically, you want ALT, AST, ALP, and bilirubin values from the liver panel, and TSH along with Free T4 from the thyroid panel. Without these reference points, any changes that emerge during supplementation become diagnostically ambiguous. A rise in liver enzymes three months into ashwagandha use could reflect supplement-driven hepatotoxicity, an unrelated condition, or an interaction with a concurrent medication. A pre-use baseline is what separates an attributable finding from an unanswerable question.
Disclose ashwagandha use to every member of your care team, not just your primary physician. This includes specialists, pharmacists, and any telehealth providers managing prescription medications on your behalf. In a fragmented care environment, information does not travel automatically between providers. A telehealth clinician titrating a GLP-1 medication cannot account for ashwagandha’s blood sugar effects, its sedative properties, or its thyroid influence unless you tell them directly. Undisclosed supplement use is one of the most common sources of diagnostic confusion in outpatient medicine.
If you choose to proceed, start at the lower end of the dose range used in clinical research, which begins around 300 mg per day of standardized root extract. Take it with food to reduce GI irritation. Monitor actively for nausea, loose stools, unusual fatigue, sedation, and any signs of liver stress including jaundice, dark urine, or upper abdominal discomfort. If any of these develop, discontinue the supplement and contact a clinician before restarting.
Elevated caution is warranted if you are pregnant, have an autoimmune condition, take thyroid medication or sedatives, have any history of liver disease, or are currently enrolled in a GLP-1 therapy program. These are not abstract warnings; each one represents a documented, mechanistically coherent interaction pathway.
Patients enrolled in a structured program that includes quarterly metabolic lab work carry a meaningful safety advantage here. Routine panels covering liver function and metabolic markers create an ongoing clinical window. Early adverse signals that might otherwise go undetected for months are visible within a single lab cycle, giving the care team an opportunity to intervene before a minor change becomes a serious one. That kind of systematic monitoring is not available to individuals self-supplementing outside of medical supervision.
The Bottom Line on Ashwagandha Side Effects
Ashwagandha is not a supplement that belongs in the “probably harmless” category. Liver injury, thyroid hormone disruption, sedation interactions, and firm contraindications for pregnant individuals and those with autoimmune conditions are all part of its documented clinical profile. Most people who take it will not experience a serious adverse event, but the risk is real, unevenly distributed, and often invisible until lab work or symptoms reveal it.
The practical takeaways from the full evidence base are straightforward: obtain baseline liver and thyroid labs before starting, disclose ashwagandha use to your physician, and monitor for warning symptoms including jaundice, unusual fatigue, or palpitations. If you are on prescription medications, particularly GLP-1 therapies, thyroid medications, immunosuppressants, or sedatives, that disclosure is not optional. It is the clinical minimum.
The “natural” label does not confer safety, and the absence of FDA dosing standards means no regulatory body has defined what a safe dose, duration, or formulation actually looks like. That gap belongs in every informed decision about this supplement.
For patients already engaged in medically supervised care, including those on GLP-1 programs, the most defensible approach is to bring supplement decisions into the clinical relationship rather than around it. Physician oversight, routine lab monitoring, and transparent communication with a care team are the tools that transform bioactive compounds, whether prescription or botanical, into manageable variables rather than unmonitored risks.