Who Should Not Take Ashwagandha (September 2026) Complete Safety Guide

Ashwagandha has become one of the most talked-about supplements in 2026. From wellness podcasts to social media, everyone seems to be discussing this ancient herb’s potential benefits for stress, anxiety, and sleep. But before you jump on the bandwagon, there is a critical question you need to answer: Who should not take ashwagandha?

This comprehensive safety guide will walk you through exactly who needs to avoid this popular adaptogen. Our team has spent months reviewing clinical studies, medical guidelines, and safety reports to bring you accurate, actionable information. Whether you are considering ashwagandha for the first time or currently taking it and wondering if it is right for you, this article covers all the contraindications, drug interactions, and medical conditions that make ashwagandha unsafe.

By the end of this guide, you will know definitively if ashwagandha is safe for your situation. You will also understand the specific risks for pregnancy, thyroid conditions, autoimmune diseases, liver health, and medication interactions. Let us start with the basics.

What Is Ashwagandha

Ashwagandha, scientifically known as Withania somnifera, is a small shrub native to India and North Africa. It has been used for over 3,000 years in traditional Ayurvedic medicine as a Rasayana, or rejuvenating tonic. The name itself gives a clue to its traditional use: “ashwagandha” translates to “smell of horse,” referring to both the root’s odor and the belief that it provides the strength of a stallion.

The active compounds in ashwagandha are called withanolides. These naturally occurring steroids are responsible for many of the herb’s biological effects. As an adaptogen, ashwagandha is believed to help the body manage stress by modulating cortisol levels and supporting the hypothalamic-pituitary-adrenal (HPA) axis.

People take ashwagandha for various reasons. The most common uses include reducing stress and anxiety, improving sleep quality, supporting healthy testosterone levels in men, enhancing athletic performance, and boosting cognitive function. Some research suggests it may help lower blood sugar and reduce inflammation markers like C-reactive protein.

Despite these potential benefits, ashwagandha is not appropriate for everyone. Its powerful effects on hormones, the immune system, and the nervous system create specific risks for certain populations. Understanding these risks is essential before starting supplementation.

Who Should Not Take Ashwagandha

Let us get straight to the critical information. The following groups of people should avoid ashwagandha entirely or use it only under strict medical supervision:

• Pregnant and breastfeeding women – Due to risks of fetal harm and lack of safety data
• People with hyperthyroidism (overactive thyroid) – Ashwagandha may worsen thyroid hormone excess
• Individuals with autoimmune diseases – Including Hashimoto’s thyroiditis, multiple sclerosis, lupus, and rheumatoid arthritis
• Those with liver disease or history of liver damage – Rare but serious cases of hepatotoxicity have been reported
• Anyone scheduled for surgery – Should stop at least 2 weeks before procedures due to sedation interaction risks
• People taking sedatives or central nervous system depressants – Additive effects can cause excessive drowsiness
• Individuals on thyroid replacement medication – Can interfere with hormone levels and TSH readings
• Those with hormone-sensitive prostate cancer – May affect testosterone and related hormones
• People taking immunosuppressant medications – Can counteract the effects of these drugs

If you fall into any of these categories, the safest choice is to avoid ashwagandha completely. For some conditions, such as hypothyroidism managed with medication, a healthcare provider might approve use with careful monitoring. However, this should never be attempted without professional guidance.

Medical Conditions That Make Ashwagandha Unsafe

Now let us examine each major contraindication in detail. Understanding why certain conditions create risk helps you make informed decisions about your health.

Pregnancy and Breastfeeding

Pregnant women should absolutely avoid ashwagandha. Animal studies have shown that high doses can cause fetal harm, including miscarriage and developmental issues. While human data is limited, the potential risks are considered too significant to ignore. Traditional Ayurvedic texts actually used ashwagandha as an abortifacient in some contexts, highlighting its potential effects on pregnancy.

For breastfeeding mothers, the concern is the lack of safety data. There are no studies confirming whether ashwagandha passes into breast milk or what effects it might have on nursing infants. Until research establishes clear safety, healthcare providers universally recommend avoiding this supplement during lactation.

If you are trying to conceive, it is also wise to avoid ashwagandha. Some evidence suggests it can affect reproductive hormones in ways that might interfere with conception or early pregnancy.

Autoimmune Diseases

People with autoimmune conditions need to exercise extreme caution with ashwagandha. The herb appears to stimulate the immune system, which could theoretically worsen autoimmune diseases where the immune system already attacks the body’s own tissues.

Specific conditions that warrant avoidance include:

• Hashimoto’s thyroiditis – Despite some online claims, the immune-stimulating effects could worsen this autoimmune thyroid condition
• Multiple sclerosis (MS) – Immune modulation could trigger flares or disease progression
• Systemic lupus erythematosus – Potential to stimulate the already overactive immune response
• Rheumatoid arthritis – May worsen symptoms by further activating immune responses
• Type 1 diabetes – Autoimmune component makes this a theoretical concern

There is some debate in the medical community about whether ashwagandha might actually help certain autoimmune conditions through immune-modulating rather than purely stimulating effects. However, without definitive research proving safety, most experts recommend avoiding it if you have any autoimmune diagnosis.

Thyroid Disorders

The thyroid contraindication is one of the most important and commonly misunderstood. Research shows that ashwagandha can significantly affect thyroid function by increasing levels of T3 and T4 hormones while potentially lowering TSH (thyroid stimulating hormone).

For people with hyperthyroidism (overactive thyroid), ashwagandha is absolutely contraindicated. The herb could further increase thyroid hormone levels, potentially causing thyrotoxicosis, a dangerous condition characterized by rapid heartbeat, anxiety, weight loss, and in severe cases, heart failure.

People with hypothyroidism (underactive thyroid) who take thyroid replacement medication face a different risk. Ashwagandha can enhance the effects of levothyroxine and similar medications, potentially causing hyperthyroid symptoms. If you have hypothyroidism and want to try ashwagandha, you must work with an endocrinologist who can monitor your TSH, T3, and T4 levels frequently.

Even people with normal thyroid function but a family history of thyroid disease should be cautious. Our team has seen forum reports of individuals developing thyroid symptoms after starting ashwagandha, suggesting it can tip vulnerable people into thyroid dysfunction.

Liver Disease

While rare, there have been documented cases of ashwagandha-associated liver injury. These cases typically involve elevated liver enzymes, jaundice, and in some instances, severe hepatitis requiring hospitalization. The exact mechanism is not fully understood, but it appears to be an idiosyncratic reaction (a rare individual sensitivity rather than a predictable dose-related toxicity).

People with existing liver disease, including hepatitis, fatty liver disease, or cirrhosis, should avoid ashwagandha entirely. The herb could potentially worsen existing liver damage or complicate treatment.

If you take ashwagandha and notice any signs of liver trouble, stop immediately and seek medical attention. Warning signs include yellowing of the skin or eyes, dark urine, pale stools, severe fatigue, nausea, and pain in the upper right abdomen.

Medications That Interact with Ashwagandha

Beyond medical conditions, ashwagandha can interact dangerously with numerous medications. These interactions occur because the herb affects multiple body systems including the central nervous system, endocrine system, and immune response.

Sedatives and Anti-Anxiety Medications

Ashwagandha has natural sedative properties through its effects on GABA receptors in the brain. When combined with pharmaceutical sedatives, this can create excessive drowsiness, confusion, and impaired coordination.

Medications in this category to watch for include:

• Benzodiazepines – Xanax (alprazolam), Valium (diazepam), Ativan (lorazepam), Klonopin (clonazepam)
• Sleep medications – Ambien (zolpidem), Lunesta (eszopiclone), Sonata (zaleplon)
• Barbiturates – Phenobarbital, pentobarbital
• Other CNS depressants – Muscle relaxants, some antihistamines

The combination can also dangerously depress breathing. If you take any sedative medication, do not use ashwagandha without explicit approval from your prescribing physician. Never combine them without medical supervision.

Thyroid Medications

As mentioned in the thyroid section, ashwagandha can alter thyroid hormone levels. For people taking thyroid replacement therapy, this creates a significant interaction risk.

Medications affected include:

• Levothyroxine (Synthroid, Levoxyl, Tirosint)
• Liothyronine (Cytomel)
• Natural desiccated thyroid (Armour Thyroid, NP Thyroid)

The interaction can go both ways. Ashwagandha might increase the absorption or effects of thyroid medication, causing hyperthyroid symptoms. Alternatively, if you stop ashwagandha after your body has adjusted, you might experience a relative drop in thyroid hormone availability. This makes careful monitoring essential if you choose to use both.

Immunosuppressants

Since ashwagandha appears to stimulate immune activity, it may counteract the effects of immunosuppressive medications. These drugs are prescribed to prevent organ rejection after transplants and to manage severe autoimmune diseases.

Immunosuppressants that could interact include:

• Corticosteroids – Prednisone, methylprednisolone, dexamethasone
• Calcineurin inhibitors – Cyclosporine, tacrolimus
• Antiproliferative agents – Mycophenolate mofetil, azathioprine
• Biologics – Adalimumab (Humira), etanercept (Enbrel), infliximab (Remicade)

Taking ashwagandha with these medications could reduce their effectiveness, potentially leading to organ rejection or autoimmune flares. The risk is significant enough that this combination should be avoided entirely.

Blood Sugar and Blood Pressure Medications

Research suggests ashwagandha may lower blood sugar and blood pressure. While this could be beneficial for some people, it creates additive effects when combined with diabetes and hypertension medications.

If you take insulin or oral diabetes medications like metformin, glipizide, or glyburide, adding ashwagandha could cause hypoglycemia (dangerously low blood sugar). Symptoms include shakiness, sweating, confusion, and in severe cases, loss of consciousness.

Similarly, blood pressure medications including ACE inhibitors, beta-blockers, and diuretics combined with ashwagandha could cause hypotension (excessively low blood pressure). This can lead to dizziness, fainting, and falls.

If you use ashwagandha with these medications, your healthcare provider needs to monitor your blood sugar and blood pressure closely. Dosage adjustments of your medications may be necessary.

Surgery Preparation: When to Stop Taking Ashwagandha

If you have surgery scheduled, you need to stop taking ashwagandha well in advance. The herb’s sedative effects can interfere with anesthesia and other medications used during and after surgical procedures.

Most healthcare providers recommend stopping ashwagandha at least 2 weeks before any scheduled surgery. This allows enough time for the herb to clear your system and reduces the risk of anesthesia complications.

Additionally, ashwagandha may affect blood sugar control during the perioperative period. Surgery already stresses blood sugar regulation, and the herb’s glucose-lowering effects could complicate this further.

Always inform your surgeon and anesthesiologist about any supplements you take, including ashwagandha. Do not assume that because it is “natural,” it is safe to continue before surgery. This is one situation where full disclosure is absolutely critical for your safety.

Side Effects to Watch For

Even if you do not fall into a high-risk category, ashwagandha can cause side effects. Knowing what to watch for helps you decide whether to continue or stop supplementation.

Common Side Effects

The most frequently reported side effects are generally mild and often resolve as the body adjusts to the supplement. Forum discussions and clinical reports indicate these occur in a significant minority of users.

Drowsiness and sedation top the list. Many users report feeling unusually sleepy, especially when starting ashwagandha or taking higher doses. This makes sense given the herb’s effects on GABA receptors.

Gastrointestinal issues are also common. Some people experience stomach upset, diarrhea, nausea, or vomiting. Taking ashwagandha with food often helps reduce these effects. Starting with a lower dose and gradually increasing may also help your digestive system adapt.

Other reported common side effects include dry mouth, headaches, and in some cases, paradoxical anxiety or insomnia. This last point surprises some users who take ashwagandha specifically for sleep or anxiety, but individual biochemistry varies.

Serious Side Effects

While rare, certain side effects require immediate medical attention. Liver damage is the most serious concern, with symptoms including yellowing skin or eyes, dark urine, severe fatigue, and abdominal pain.

Allergic reactions, though uncommon, can occur. Signs include rash, itching, hives, swelling of the face or throat, and difficulty breathing. If you experience these symptoms, stop taking ashwagandha immediately and seek emergency care.

Hormonal changes warrant attention. Men experiencing breast tenderness or enlargement, or women noticing menstrual changes, should consult a healthcare provider. These could indicate that ashwagandha is affecting your endocrine system in unexpected ways.

Some users report heart palpitations or rapid heartbeat. While research suggests ashwagandha may actually support heart health in some contexts, any cardiac symptoms require medical evaluation to rule out serious issues.

When to Talk to Your Doctor

Given the complexity of ashwagandha’s interactions and contraindications, consulting a healthcare provider before starting supplementation is wise for almost everyone. But there are specific situations where this consultation becomes essential.

Schedule an appointment before taking ashwagandha if you have any chronic medical condition, even if it is not listed in the major contraindications. Diabetes, heart disease, kidney disease, and mental health conditions all warrant professional input.

If you take any prescription medication, bring a complete list to your appointment. Include over-the-counter drugs and other supplements as well. Your doctor can check for interactions specific to your regimen.

Women who are pregnant, trying to conceive, or breastfeeding should not take ashwagandha at all without explicit medical approval. Given the safety concerns, most doctors will advise against use during these life stages.

People with a family history of thyroid disease, autoimmune conditions, or liver problems should discuss these risk factors. You may be more susceptible to adverse effects even if you currently have no diagnosed condition.

Questions to ask your healthcare provider include: Is ashwagandha safe given my specific health history? What dosage would be appropriate if you approve it? How should I monitor for side effects? Are there particular symptoms that should prompt me to stop immediately? What alternatives might provide similar benefits with less risk?

Frequently Asked Questions

Conclusion

Who should not take ashwagandha? As we have explored in this comprehensive guide, the answer includes pregnant and breastfeeding women, people with hyperthyroidism or certain autoimmune diseases, individuals with liver conditions, those scheduled for surgery, and anyone taking sedatives, thyroid medications, or immunosuppressants.

The popularity of ashwagandha in 2026 has led many to view it as a harmless wellness supplement. However, its powerful effects on hormones, the immune system, and the nervous system create real risks for specific populations. Understanding these contraindications is not about fear-mongering; it is about making informed decisions that protect your health.

If you do not fall into any high-risk category and are considering ashwagandha, remember to start with a low dose, monitor for side effects, and discuss your plans with a healthcare provider. Even safe supplements affect everyone differently, and professional guidance ensures you get benefits without unnecessary risks.

Your health is worth the extra diligence. Whether ashwagandha is right for you depends on your unique medical history, current medications, and health goals. Use the information in this guide as a starting point for an informed conversation with your healthcare team.