Ashwagandha: Side Effects, Contraindications, and Essential Precautions

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Ashwagandha: Side Effects, Contraindications, and Essential Precautions

By | March 15, 2026

Ashwagandha (Withania somnifera) is an adaptogen revered in Ayurvedic medicine for its ability to help the body manage stress and promote balance. While generally considered safe for most people when consumed in appropriate doses, it is crucial to understand its potential side effects and contraindications. These include, but are not limited to, mild digestive discomfort, drowsiness, and important precautions for pregnant or breastfeeding women, individuals with autoimmune diseases, thyroid disorders, or those taking certain medications. At Kóre Labs, our mission is to provide you with the science behind each adaptogen for informed and safe use.

Table of Contents

What is Ashwagandha and Why is it So Popular?

Ashwagandha, also known as "Indian ginseng," is an adaptogenic herb that has been used for millennia for its restorative and balancing properties. Its popularity stems from its ability to help the body adapt to physical and psychological stress, improve sleep quality, and support cognitive function. At Kóre Labs, we have thoroughly explored its benefits in our article Ashwagandha Capsules: Benefits, Scientific Evidence, and Optimal Use, where we delve into the science behind this powerful adaptogen. To understand more about how adaptogens work at a cellular level, we invite you to read Adaptogens: Extraction, Active Components, and Mechanisms of Action.

General Safety Profile of Ashwagandha

Numerous clinical studies have evaluated the safety of Ashwagandha, finding that it is generally well-tolerated by most healthy individuals when consumed at recommended doses and for defined periods. Toxicity is rare, and most adverse effects are mild and transient [1]. However, "generally safe" does not mean "safe for everyone" or "without precautions." It is essential to consider biological individuality and pre-existing health conditions.

Common and Mild Side Effects of Ashwagandha

The most frequently reported side effects of Ashwagandha are mild in nature and generally resolve with dose adjustment or discontinuation of use. These include:

  • Digestive Upset: Some people may experience nausea, vomiting, diarrhea, or stomach pain, especially if taken on an empty stomach or in high doses. Taking it with food can help mitigate these symptoms.
  • Drowsiness or Sedation: Given its ability to promote relaxation and improve sleep, Ashwagandha can cause drowsiness in some individuals, especially if combined with other sedatives or if taken during the day.
  • Allergic Reactions: Although rare, allergic reactions such as skin rashes, itching, or difficulty breathing may occur in people sensitive to nightshades (the family to which Ashwagandha belongs).

Rare or Potentially Serious Side Effects

Although infrequent, there are reports of more serious side effects that warrant greater caution and consultation with a healthcare professional.

Interactions with Thyroid Function

Ashwagandha has been shown to modulate thyroid function, increasing thyroid hormone levels in some studies [2]. This can be beneficial for individuals with subclinical hypothyroidism but represents a significant contraindication for:

  • People with hyperthyroidism.
  • Individuals taking thyroid medications (such as levothyroxine), as it could potentiate their effect and lead to an excess of thyroid hormones.

If you have a thyroid condition or take medication, it is IMPERATIVE to consult your doctor before starting Ashwagandha supplementation.

Impact on Blood Glucose and Blood Pressure

Studies suggest that Ashwagandha may have a hypoglycemic (blood sugar-lowering) effect and a hypotensive (blood pressure-lowering) effect [3]. While this can be beneficial for some people, it becomes an important precaution for:

  • People with diabetes taking blood sugar medications, as it could cause hypoglycemia.
  • Individuals with low blood pressure or those taking antihypertensive medications, as it could lower blood pressure to dangerous levels.

Potential Liver Problems (Extremely Rare)

Although extremely rare, there are isolated reports of liver damage associated with Ashwagandha use [4]. Direct causality is difficult to establish and is often associated with contaminated products or excessively high doses. However, if you have pre-existing liver disease, caution is paramount, and medical consultation is mandatory before using it.

Key Contraindications of Ashwagandha

The contraindications of Ashwagandha are situations in which its use is inadvisable or prohibited due to significant health risks.

Pregnancy and Breastfeeding

Ashwagandha is considered an absolute contraindication during pregnancy and breastfeeding. Traditionally, it has been used in some cultures to induce abortion, and although modern scientific evidence is limited, there is insufficient data to guarantee its safety. As a precaution, pregnant or breastfeeding women should avoid Ashwagandha entirely.

Autoimmune Diseases

Due to its ability to modulate the immune system (it has been shown to increase immune activity), Ashwagandha is contraindicated in people with autoimmune diseases such as:

  • Multiple sclerosis (MS)
  • Systemic lupus erythematosus (SLE)
  • Rheumatoid arthritis (RA)
  • Hashimoto's disease

In these cases, Ashwagandha could exacerbate symptoms by stimulating an already overactive immune response.

Interactions with Specific Medications

Ashwagandha can interact with various types of medications, altering their effectiveness or increasing the risk of adverse effects. Always consult your doctor if you take:

  • Immunosuppressants: Could reduce the effectiveness of these medications by stimulating the immune system.
  • Sedatives or Anxiolytics (e.g., Benzodiazepines, Barbiturates): Could potentiate their sedative effects and cause excessive drowsiness.
  • Diabetes Medications: Could cause hypoglycemia by adding to their blood sugar-lowering effects.
  • Blood Pressure Medications: Could cause hypotension by adding to their blood pressure-lowering effects.
  • Thyroid Hormones: Could potentiate the effect of levothyroxine.

Before Surgery

Due to its possible sedative effects, as well as its impact on blood sugar levels and blood pressure, it is recommended to discontinue Ashwagandha use at least two weeks before any scheduled surgery. This helps prevent interactions with anesthesia and maintain physiological stability during and after the procedure.

Recommended Dosage and How to Minimize Risks

To minimize the side effects of Ashwagandha and ensure its effectiveness, it is essential to adhere to recommended doses and opt for high-quality products. At Kóre Labs, we recommend our Ashwagandha (Withania somnifera), formulated with standardized extract to guarantee purity and potency. It is always advisable to:

  • Start with a Low Dose: Allows your body to adapt and evaluate your tolerance.
  • Take with Food: This can reduce digestive discomfort.
  • Consult a Healthcare Professional: Especially if you have pre-existing medical conditions or take other medications.

The Importance of Quality: The Kóre Standard

At Kóre Labs, our "Quality or Nothing" value is non-negotiable. The purity and potency of adaptogens are crucial to ensure both efficacy and safety. Low-quality or adulterated products may contain impurities or inconsistent dosages, increasing the risk of unwanted side effects or supplement ineffectiveness. Our Ashwagandha undergoes rigorous laboratory testing to ensure you receive only the best, backed by our "Science First" philosophy.

Conclusion: Responsible and Conscious Use

Ashwagandha is a powerful ally for well-being, but like any bioactive substance, it demands respect and knowledge. Understanding its potential side effects and contraindications is an essential step for safe and responsible use. At Kóre Labs, we empower you with evidence-based information so you can make informed decisions about your health. Your rebirth begins today, with knowledge and quality.

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Frequently Asked Questions About Ashwagandha

What are the most common side effects of Ashwagandha?

The most common side effects are mild and transient, including digestive discomfort (nausea, diarrhea, stomach pain) and drowsiness. Taking it with food can help reduce digestive upset.

Who should NOT take Ashwagandha?

Ashwagandha is contraindicated in pregnant or breastfeeding women, people with autoimmune diseases (such as lupus, rheumatoid arthritis, multiple sclerosis, Hashimoto's), and those taking immunosuppressants, sedatives, diabetes medications, or blood pressure medications. It should also be avoided before surgery.

Does Ashwagandha interact with thyroid medications?

Yes, Ashwagandha can increase thyroid hormone levels. If you have a thyroid condition or take medications like levothyroxine, it is crucial to consult your doctor before using Ashwagandha to avoid an excess of thyroid hormones or interactions.

How long can Ashwagandha be taken safely?

Most safety studies have evaluated Ashwagandha use for periods of 1 to 3 months. For long-term use, it is advisable to consult a healthcare professional to ensure there are no unwanted cumulative effects and to determine the appropriate dosage.

Can Ashwagandha cause liver damage?

Reports of liver damage associated with Ashwagandha are extremely rare and often difficult to attribute directly to the supplement, potentially being related to contaminated products or excessive doses. However, if you have a pre-existing liver condition, caution is key and medical consultation is mandatory before using it.

Scientific References

  1. Singh, N., Bhalla, M., de Jager, P., & Gilca, M. (2011). An overview on Ashwagandha: A Rasayana (rejuvenator) of Ayurveda. African Journal of Traditional, Complementary and Alternative Medicines, 8(5 Suppl), 208–213. PMC3252722
  2. Sharma, A. K., Basu, I., & Singh, S. (2018). Efficacy and Safety of Ashwagandha (Withania somnifera (L.) Dunal) Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial. Journal of Complementary and Integrative Medicine, 16(1). DOI: 10.1515/jcim-2017-0050
  3. Andallu, B., & Radhika, B. (2000). Hypoglycemic, diuretic and hypocholesterolemic effect of winter cherry (Withania somnifera, Dunal) root. Indian Journal of Experimental Biology, 38(6), 607–609. PubMed: 10985241
  4. Björnsson, E. S., & LaCouture, L. (2020). Ashwagandha (Withania somnifera) induced liver injury: a case series from the Swedish Adverse Drug Reaction Advisory Committee. Journal of Clinical Gastroenterology, 54(1), 89-93. PubMed: 31589218
  5. Mishra, L. C., Singh, B. B., & Dagenais, S. (2001). Scientific basis for the therapeutic use of Withania somnifera (Ashwagandha): A review. Alternative Medicine Review, 5(4), 334–346. PubMed: 11550993

Health Disclaimer

The information provided in this Kóre Labs article is for educational and informational purposes only and should not be construed as professional medical advice. Always consult a qualified healthcare professional before starting any new supplement, diet, or exercise regimen, or if you have questions about a medical condition. Supplements are not intended to diagnose, treat, cure, or prevent any disease. Results may vary individually. Kóre Labs adheres to "Science First" and "Quality or Nothing," but individual responsibility in supplement use is paramount.

⚕️ Important notice

This content is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment prescription. Dietary supplements are not medicines and are not intended to diagnose, treat, cure, or prevent any disease (General Health Law, Art. 306; Advertising Regulations, COFEPRIS).

Consult a healthcare professional before starting any supplementation regimen, especially if you are pregnant, breastfeeding, taking medication, or have any medical condition. Individual results may vary.

The scientific references cited support the informational nature of this article and do not imply that Kóre Labs products replicate the exact conditions of the referenced studies.