Ashwagandha Side Effects: Is It Safe and Who Should Be Careful?

Ashwagandha side effects are easy to oversimplify. One side of the internet treats ashwagandha as harmless because it is a traditional herb. The other treats isolated safety reports as proof that the ingredient is broadly dangerous. Neither view is useful.

The more accurate picture is that specific ashwagandha extracts have generally been well tolerated in many short-term clinical trials, while mild effects such as stomach upset and drowsiness can occur. Rare liver-injury reports and potential thyroid effects also mean that some people should be more cautious, especially when medical conditions or medications are involved.

What are the most common ashwagandha side effects?

According to the U.S. National Center for Complementary and Integrative Health (NCCIH) and the NIH Office of Dietary Supplements, the more commonly reported side effects are usually mild. They include:

• Stomach upset or gastrointestinal discomfort

• Loose stools or diarrhea

• Nausea

• Drowsiness or feeling sleepy

These effects do not happen to everyone, and their frequency varies by extract, dose, study population and duration. That is one reason it is misleading to talk about “ashwagandha” as if every preparation were identical.

Is ashwagandha safe? Short-term trials are reassuring—but not a blank cheque

The controlled-trial data are more reassuring than many alarming headlines suggest. In a 2026 randomized, double-blind, placebo-controlled study involving 1,002 adults, a specific standardized ashwagandha root extract was used at 600 mg per day for eight weeks. No serious adverse events were reported, and laboratory testing did not show significant differences in liver, kidney or hematologic safety markers between the ashwagandha and placebo groups.

That is meaningful evidence, but it does not prove that every ashwagandha product is risk-free. It studied one defined extract, at one dose, for eight weeks. Safety data from one preparation should not automatically be transferred to a different extract, dose, plant-part combination or multi-ingredient formula.

NCCIH currently describes short-term use—up to about three months—as potentially safe for many people, while noting that there is not enough information to draw firm conclusions about long-term safety. A small 2025 randomized trial followed one standardized root extract for 180 days and reported good tolerability, but a 40-person study is not enough to establish population-wide long-term safety.

Rare liver injury: a real signal, but not a common-side-effect statistic

Liver injury deserves careful wording because both minimization and exaggeration are mistakes. NCCIH and NIH note that ashwagandha supplements have been linked to liver injury in a small number of reports.

A 2023 case series from India described eight cases associated with single-ingredient ashwagandha formulations after the investigators excluded several competing exposures. Cholestatic hepatitis was the most common pattern. Outcomes were especially serious in several patients who already had chronic liver disease. Earlier case series from Iceland and the U.S. Drug-Induced Liver Injury Network also described suspected ashwagandha-associated liver injury.

What those reports can tell us: liver injury is a plausible rare adverse event that should not be ignored.

What they cannot tell us: how often liver injury occurs among all ashwagandha users. Case series do not provide an incidence rate or prove that every formulation carries the same risk.

What about the thyroid?

Ashwagandha may affect thyroid function in some people. NIH summarizes small clinical studies in which thyroid hormone measures changed during ashwagandha use, and rare case reports have described thyrotoxicosis or thyroiditis that improved after the supplement was stopped.

This does not mean ashwagandha routinely causes thyroid disease. It does mean that people with a thyroid disorder—or anyone taking thyroid hormone medication—should not treat the supplement as automatically neutral.

If you have a thyroid condition or take thyroid medication, discuss ashwagandha with your physician or pharmacist before using it.

Pregnancy and breastfeeding

Health Canada’s current Ashwagandha monograph advises people who are pregnant or breastfeeding to ask a healthcare practitioner before use. NCCIH takes a more conservative position and advises avoiding ashwagandha during pregnancy and not using it while breastfeeding.

The practical conclusion is simple: pregnancy and breastfeeding are not situations for self-experimentation with ashwagandha. Speak with a qualified healthcare professional first.

Drowsiness, alcohol and other sedating products

Drowsiness is one of the better-established practical cautions. Health Canada’s 2025 ingredient monograph says to use caution when driving or operating machinery because drowsiness may occur.

The current Biogénique Ashwagandha label is even more specific about combinations: consumption with alcohol, other drugs or natural health products with sedative properties is not recommended.

That means “natural” does not make stacking multiple sleep or calming products automatically safe. If several products can make you drowsy, their combined effect may be more than you expected.

Medication interactions and situations that deserve extra caution

NCCIH identifies several medication categories that may interact with ashwagandha. These include:

• Sedatives

• Anti-seizure medications (anticonvulsants)

• Thyroid hormone medications

• Medications for diabetes

• Medications for high blood pressure

• Immunosuppressant medications

NCCIH also advises against use in people who are about to have surgery and does not recommend ashwagandha for people with autoimmune or thyroid disorders without medical guidance. It additionally raises a caution for men with hormone-sensitive prostate cancer.

This list is not exhaustive. If you take prescription medication, the safer question is not “Can ashwagandha interact with drugs?” but “Does it interact with my specific medication and condition?” A pharmacist or prescribing clinician can answer that much better than a generic supplement chart.

Health Canada: the current ingredient monograph vs. the Biogénique product label

There are two different documents worth understanding. The Biogénique product label tells you the directions and cautions licensed for this specific finished product. Health Canada’s current ingredient monograph is broader guidance used for natural health product licensing and labelling.

Important: the current Health Canada monograph was revised on February 28, 2025. The article therefore keeps the specific Biogénique label wording separate from newer ingredient-monograph guidance rather than pretending they are identical documents.

Biogénique Ashwagandha: product facts verified in Drive

What the COA can—and cannot—tell you about safety

Biogénique’s Certificate of Analysis for lot 240525 supports a different part of the safety conversation: finished-product quality control. The lot report lists microbial testing, four specified pathogens, heavy-metal testing, capsule weight and disintegration performance.

What this supports: the tested lot met the listed finished-product specifications in the COA.

What it does not prove: that no user can experience an adverse reaction, medication interaction, allergy, liver injury or thyroid effect. Batch quality testing and individual clinical safety are related, but they are not the same question.

How to lower avoidable risk if you use ashwagandha

1. Follow the product label. For Biogénique Ashwagandha, the reviewed label says adults take 1 capsule once daily. Do not increase the dose simply because another study used more.

2. Review medications and medical conditions first. This matters especially for thyroid disease, autoimmune conditions, diabetes, blood pressure treatment, seizure medications, immunosuppressants and sedatives.

3. Do not casually combine sedating substances. The Biogénique label specifically advises against consumption with alcohol, drugs or natural health products with sedative properties.

4. Treat drowsiness as a real effect. Do not drive or operate machinery if you feel impaired.

5. Stop and seek medical advice for concerning symptoms. Jaundice, persistent nausea, marked fatigue, itching or significant abdominal discomfort are not normal “detox” signs.

6. Use a clearly identified product and batch. A visible NPN, exact extract information and accessible batch testing make it easier to know what you are actually taking.

Frequently asked questions

Is ashwagandha safe to take every day?

Short-term studies of specific extracts are generally reassuring, and NCCIH says ashwagandha may be safe for up to about three months in many people. Evidence for routine use over many months or years is still limited, so “safe every day forever” is not an evidence-based conclusion.

Can ashwagandha cause liver damage?

Rare cases of suspected ashwagandha-associated liver injury have been published. The reports are important, but they do not establish how common the problem is among all users. People with pre-existing liver disease should be especially cautious and discuss use with a healthcare professional.

Does ashwagandha make you sleepy?

It can. Drowsiness is a recognized possible side effect, and Health Canada’s current monograph advises caution when driving or operating machinery. The Biogénique label also advises against combining the product with alcohol or other substances that have sedative properties.

Can I take ashwagandha if I have a thyroid condition?

Do not assume it is neutral. Research and case reports suggest ashwagandha can affect thyroid function in some people, and it may interact with thyroid hormone medication. Speak with your clinician or pharmacist first.

Can I take ashwagandha with antidepressants or anxiety medication?

There is no one answer for every medication. Because ashwagandha can cause drowsiness and may interact with some central-nervous-system medicines, do not rely on a generic interaction list. Ask a pharmacist or prescribing clinician about your specific drug and dose before combining them.

Can I drink alcohol while taking Biogénique Ashwagandha?

The current Biogénique product label says consumption with alcohol, drugs or natural health products with sedative properties is not recommended.

Is ashwagandha safe during pregnancy or breastfeeding?

Health Canada’s current monograph says to ask a healthcare practitioner before use if pregnant or breastfeeding. NCCIH advises avoiding use during pregnancy and not using it while breastfeeding. Do not self-start ashwagandha in either situation.

The bottom line

Ashwagandha is not best described as either “completely harmless” or “dangerous.” For many healthy adults, specific extracts have been well tolerated in short-term trials. Mild gastrointestinal effects and drowsiness can occur, while rare liver-injury reports and possible thyroid effects justify more caution in certain people.

The smartest approach is to match the evidence to the exact product, follow the licensed dose, check your medications and health conditions, and take safety symptoms seriously instead of assuming that a traditional botanical cannot cause adverse effects.

For Biogénique Ashwagandha specifically, the reviewed label provides 500 mg of 10:1 root extract (QCE 5,000 mg), NPN 80067337, at 1 capsule once daily for adults, and lot 240525 has a finished-product COA available for review.

View Biogénique Ashwagandha   |   View Quality Control / COAs

Evidence & Compliance Note

This article deliberately separates three evidence layers: (1) the specific directions and cautions printed on the Biogénique NPN 80067337 label reviewed in Google Drive; (2) Health Canada’s current 2025 Ashwagandha ingredient monograph; and (3) broader safety evidence from government health agencies and published clinical literature. Safety findings from other extracts are not presented as proof that the Biogénique formulation will produce identical outcomes.

References

1. Health Canada. Ashwagandha – Withania somnifera Monograph. February 28, 2025.

2. National Center for Complementary and Integrative Health (NCCIH). Ashwagandha: Usefulness and Safety.

3. NIH Office of Dietary Supplements. Ashwagandha: Health Professional Fact Sheet.

4. Safety of 8-Week Administration With Ashwagandha Root Extract in Adults With Stress and Anxiety: randomized placebo-controlled trial (2026). PubMed PMID 41943502.

5. Philips CA, et al. Ashwagandha-induced liver injury—A case series from India and literature review. Hepatology Communications. 2023. PubMed PMID 37756041.

6. Björnsson HK, et al. Ashwagandha-induced liver injury: case series from Iceland and the U.S. Drug-Induced Liver Injury Network. Liver International. PubMed PMID 31991029.

7. Kamada Y, et al. Painless Thyroiditis by Withania somnifera (Ashwagandha). 2024. PubMed PMID 38559552.

8. Vaidya N, et al. Safety and Tolerability of Withania somnifera Root Extract in Healthy Male Participants: 180-day randomized trial. 2025. PubMed PMID 41458530.

9. Biogénique Ashwagandha product page — NPN 80067337.

10. Biogénique Quality Control — Ashwagandha lot 240525 COA listing.

Internal Biogénique verification: NPN 80067337 Product Facts/label and Certificate of Analysis for lot 240525 were checked directly against the connected Biogénique Google Drive before finalization.

Disclaimer

This article is for educational purposes only and is not medical advice. Natural health products are not appropriate for everyone. Follow the product label and speak with a qualified healthcare professional if you are pregnant or breastfeeding, take medications, have a thyroid, autoimmune, liver or other medical condition, are preparing for surgery, or have questions about whether ashwagandha is appropriate for you.