Ashwagandha Side Effects: What You Need to Know

Ashwagandha, also known as Withania somnifera, has become increasingly popular in the United States as a natural supplement for stress, anxiety, and sleep support. However, like all botanical substances, ashwagandha can cause side effects in some users. Understanding these potential effects is crucial for making informed decisions about whether this herb is right for you. This comprehensive guide explores the common and uncommon side effects of ashwagandha, who should avoid it, and how to use it safely.

Common Side Effects of Ashwagandha

Most people who take ashwagandha experience only mild side effects, if any. The most frequently reported adverse effects are generally considered manageable and temporary. According to research from leading medical institutions, common side effects include stomach upset, loose stools, nausea, and drowsiness. These mild symptoms typically resolve on their own without requiring medical intervention.

Gastrointestinal Issues represent the most prevalent category of side effects reported by ashwagandha users. Some individuals experience stomach irritation, diarrhea, or loose bowel movements after taking the supplement. Additionally, nausea and headaches have been reported in clinical studies, though these symptoms were generally managed through standard symptom-relief therapies. The gastrointestinal disturbances are often dose-dependent, meaning higher doses increase the likelihood of experiencing these effects.

Drowsiness and Sleep Disturbances occur because ashwagandha is traditionally used to promote relaxation and improve sleep quality. However, some users report excessive drowsiness or fatigue during daytime hours, which can interfere with daily activities. This side effect is particularly important to note if you plan to drive or operate machinery after taking ashwagandha.

Less Common Side Effects

Beyond the typical mild effects, some users report less frequently occurring symptoms. These include giddiness, vertigo, nasal congestion, cough, decreased appetite, constipation, dry mouth, hyperactivity, nocturnal cramps, blurring of vision, hyperacidity, skin rash, and weight gain. While these effects are uncommon, they demonstrate that ashwagandha can affect various body systems in certain individuals.

Headaches, though relatively uncommon, have been documented in clinical settings. Additionally, some users report a sensation of itching or discoloration of the skin and mucous membranes, though these reactions appear to be rare.

Serious and Rare Side Effects

While uncommon, ashwagandha has been associated with several serious adverse effects in case reports. Understanding these potential complications is important, particularly for individuals with pre-existing health conditions.

Liver-Related Complications

Liver injury represents one of the most concerning potential serious side effects associated with ashwagandha use. Multiple case reports have documented acute liver injury in individuals taking ashwagandha supplements, with symptoms including jaundice, itching, nausea, lethargy, abdominal discomfort, and elevated liver enzymes. These cases involved individuals taking 450 to 1,350 mg of ashwagandha daily over periods ranging from one week to four months.

A particularly noted case involved a 20-year-old man in Japan who developed liver dysfunction and elevated bilirubin levels after using ashwagandha in combination with multiple antianxiety medications. Healthcare providers have observed additional cases of liver injury, some occurring in individuals with pre-existing liver disease. Importantly, liver function typically improved after discontinuing ashwagandha use, with some patients requiring additional medical treatment.

Thyroid Function Effects

Thyrotoxicosis, a condition characterized by excessive thyroid hormone levels, has been reported in association with ashwagandha use. Three documented cases involved women aged 32 to 73 years who developed thyrotoxicosis after taking ashwagandha for chronic fatigue, hypothyroidism, and insomnia. One case involved an unusually high dose of 1,950 mg daily for more than two months. Fortunately, discontinuing ashwagandha resolved the thyrotoxicosis in all reported cases.

Cardiovascular Issues

Two cases of ventricular tachycardia, an abnormal heart rhythm, were possibly associated with the use of herbomineral preparations containing ashwagandha. Additionally, increased heart rate variability has been documented in clinical studies.

Other Serious Complications

Additional rare but serious effects documented in medical case reports include kidney transplant rejection, reversible cerebral vasoconstriction syndrome, and acute steatohepatitis (fatty liver inflammation). A case of reversible cerebral vasoconstriction syndrome occurred in a woman using ashwagandha in combination with medical marijuana and a serotonin-norepinephrine reuptake inhibitor (SNRI), with symptoms resolving after conventional treatment. In one case of acute steatohepatitis, a 43-year-old female had taken multiple supplements including ashwagandha along with alcohol and ibuprofen, making it difficult to isolate ashwagandha as the sole causative agent.

Important Warnings and Contraindications

Certain populations should avoid ashwagandha entirely due to specific health conditions or medication use.

Pregnancy and Breastfeeding

Pregnant women should not use ashwagandha. Medical evidence suggests that ashwagandha may induce spontaneous abortion, particularly at higher doses. Several countries and health agencies have issued warnings about this potential risk. In 2020, the Technical University of Denmark released a risk assessment discussing ashwagandha’s potential abortifacient effects, leading Denmark to ban ashwagandha use in 2023. In 2024, the French Agency for Food, Environmental, and Occupational Health and Safety (ANSES) issued a statement recommending against ashwagandha use in pregnant and breastfeeding women.

It is important to note that the American Herbal Pharmacopoeia (AHP) has stated that their earlier report on ashwagandha has been misrepresented and that there is no definitive evidence that ashwagandha root causes abortions. However, given the controversy and potential risks, pregnant and breastfeeding women should err on the side of caution and avoid this supplement.

Hormone-Sensitive Prostate Cancer

Men with hormone-sensitive prostate cancer should avoid ashwagandha or consult with their oncologist before use. Ashwagandha may increase testosterone levels, which can interfere with cancer treatment protocols designed to suppress testosterone. The herb’s potential to elevate testosterone presents a significant concern for this patient population.

Thyroid Conditions

Individuals with existing thyroid disorders, including hypothyroidism and hyperthyroidism, should avoid ashwagandha or use it only under medical supervision. The herb’s potential to affect thyroid hormone levels and interact with thyroid medications makes it unsuitable for this population without professional guidance.

Autoimmune Disorders

People with autoimmune conditions should avoid ashwagandha, as the herb may stimulate immune function and potentially exacerbate autoimmune disease symptoms.

Drug Interactions and Medication Concerns

Ashwagandha can interact with several medication classes, potentially reducing medication effectiveness or increasing side effects.

Central Nervous System Depressants

Ashwagandha has sedative and GABAnergic properties, meaning it affects the same neurotransmitter system as certain medications. Individuals taking benzodiazepines, anticonvulsants, barbiturates, or other sedative medications should avoid ashwagandha or consult their healthcare provider before use, as the combination may cause excessive drowsiness and impaired cognitive function.

Thyroid and Hormone Medications

Ashwagandha may interact with thyroid medications by altering thyroxine levels. Additionally, the herb’s effects on hormone levels make it potentially problematic when combined with hormone-related medications.

Other Medication Interactions

Healthcare providers should be informed about ashwagandha use if you take antidiabetes medications, antihypertensives, or immunosuppressants, as interactions are possible. The supplement may also cause a false elevation in digoxin immunoassay tests, which is important for patients on digoxin therapy for heart conditions.

Safety and Duration of Use

Ashwagandha appears to be well tolerated for short-term use of up to approximately three months. Most clinical trials demonstrating safety and efficacy have studied participants using ashwagandha for periods of three months or less. However, evidence regarding the safety of prolonged use over many months or years remains limited.

This lack of long-term safety data is significant for individuals considering ashwagandha as a chronic supplement. Until more research emerges on extended use, healthcare providers recommend cautious use and regular check-ins with medical professionals for those using ashwagandha beyond the three-month window.

Quality and Contamination Concerns

One important consideration involves product quality and potential contamination. In one documented case, hemolytic anemia and abdominal pain were reported following ingestion of ashwagandha and mucuna pills containing high amounts of lead. Symptoms resolved with standard treatment after discontinuing the contaminated product.

This case highlights the importance of purchasing ashwagandha supplements from reputable manufacturers that conduct independent testing for contaminants and verify product contents. Not all supplements are created equal, and product quality can vary significantly between manufacturers.

Frequently Asked Questions

Q: Is ashwagandha safe for everyone?

A: Ashwagandha is not safe for everyone. Pregnant women, breastfeeding women, men with hormone-sensitive prostate cancer, people with thyroid conditions, and those with autoimmune disorders should avoid it. Additionally, individuals taking sedative medications, thyroid medications, or other specific drug classes should consult their healthcare provider before use.

Q: How long can I safely take ashwagandha?

A: Clinical evidence supports ashwagandha use for up to three months. Evidence on prolonged use beyond this period is limited, so extended use should only occur under medical supervision.

Q: What should I do if I experience side effects from ashwagandha?

A: Most mild side effects resolve on their own or with standard symptom management. However, if you experience severe symptoms such as jaundice, abdominal pain, excessive drowsiness, or chest discomfort, discontinue use immediately and contact your healthcare provider.

Q: Can ashwagandha cause liver damage?

A: While rare, ashwagandha has been associated with acute liver injury in some cases. Individuals should be aware of warning signs including jaundice, itching, nausea, and abdominal discomfort, and should report these symptoms to their healthcare provider immediately.

Q: Does ashwagandha interact with other supplements?

A: Ashwagandha can interact with other supplements, particularly those with sedative effects or hormonal impacts. The case of acute steatohepatitis involved ashwagandha combined with multiple other supplements and alcohol, making it important to inform your healthcare provider of all substances you are taking.

Q: How much ashwagandha is too much?

A: Documented cases of serious side effects have involved doses ranging from 450 to 1,350 mg daily. Typical supplemental doses are much lower, but any dose decisions should be made in consultation with a healthcare provider.

Recommendations for Safe Use

Before starting ashwagandha, consult with your healthcare provider to ensure it is appropriate for your individual health situation. Disclose all current medications, supplements, and existing health conditions. Start with the lowest recommended dose to assess tolerance, and discontinue immediately if you experience severe symptoms. Purchase ashwagandha from reputable manufacturers that provide third-party testing verification. Monitor for warning signs including changes in liver function, excessive drowsiness, skin reactions, or thyroid symptoms. Limit use to the three-month period supported by clinical evidence unless your healthcare provider specifically recommends extended use. Keep regular appointments with your healthcare provider if using ashwagandha, particularly if you have pre-existing health conditions or take multiple medications.

Conclusion

While ashwagandha is widely used and generally considered safe for short-term use in healthy individuals, it is not without potential risks. Mild side effects such as stomach upset and drowsiness are most common and typically manageable. However, rare serious effects including liver injury, thyroid dysfunction, and cardiovascular changes have been documented. Certain populations—including pregnant women, men with hormone-sensitive prostate cancer, those with thyroid disorders, and individuals with autoimmune conditions—should avoid ashwagandha entirely. Understanding these risks and discussing ashwagandha use with a healthcare provider ensures informed decision-making and safe supplementation practices.

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medha deb

 

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

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