If you’ve ever done an internet search for natural anxiety treatments, you’ve probably heard of ashwagandha. Maybe that’s what brought you here. This herb is known for its stress-relieving and anti-inflammatory properties. But what results can you actually expect from taking an over-the-counter ashwagandha supplement? We talked with two doctors to learn more.
What is ashwagandha, and how does it work?
Dr. Jeff Chen is the co-founder and CEO of Radicle Science, an organization that conducts large clinical trials on wellness products, including supplements like ashwagandha. He says, “Ashwagandha is high in phytochemicals (naturally occurring plant compounds) and has been traditionally used in Ayurvedic medicine.” As Johns Hopkins explains, Ayurvedic medicine is a holistic ideology that takes a natural approach to wellness. This system of medicine has origins in India dating back over 3,000 years.
This herb is often associated with calmness and anxiety mitigation, and there’s a good reason for that. Ashwagandha is an adaptogen, Chen says. In other words, as the doctor explains, it is “a botanical compound that may help the body adapt to stressors and maintain homeostasis,” or a balance of your internal systems.
More specifically, ashwagandha “is known for its ability to help the body manage stress by regulating cortisol, the body’s primary stress hormone.” This is according to Dr. Andrew Youssouf, a dual board-certified physician and the medical director at Ikon Recovery. He reports that the herb “also helps promote a sense of calm and resilience to stress by supporting the adrenal glands and influencing the nervous system.”
Ashwagandha supplements and safety
Generally speaking, the ashwagandha root is safer to take than the plant’s leaves.
“The root extract is the most commonly studied and used in traditional medicine because it contains a higher concentration of withanolides, the active compounds responsible for ashwagandha’s health benefits,” Youssouf says. He says ashwagandha leaf extract is less commonly used and may have a different chemical composition, making its effects less predictable.
Chen adds, “The Indian government’s Department of Ayurveda recommends the sole use of the roots, and they advise against the use of ashwagandha leaves since there is not enough evidence for their safety and benefits.”
Chen says that “the majority of the high-quality clinical research to date has been conducted on KSM-66 branded ashwagandha, which is a standardized extract from the root of the plant.”
The FDA doesn’t regulate or approve dietary supplements the same way it does with other pharmaceuticals or over-the-counter meds like ibuprofen. This means supplements can be sold without proof of effectiveness, purity or safety. That being said, there are still ways to evaluate the potential quality of a supplement. Chen has some recommendations for assessing ashwagandha products:
- Randomized controlled trial: Look for ashwagandha supplements that have undergone at least one randomized controlled trial on their specific product. Many brands reference research on individual ingredients, but Chen says ingredients may counteract each other and absorb differently based on the product’s form factor. It’s better to research information about the brand’s unique formulation.
- Clinically proven: Review the fine print when a brand says it is “clinically proven.” The doctor warns that brands may use that phrase even though their data is from low-quality consumer studies. You want to look for a study that uses the key terms of a rigorous, gold-standard clinical trial — which include “placebo,” “blinded” and “randomized.”
- Test subjects: Shop for supplements that have been clinically tested on at least 100 people. Ideally, the research should be conducted on Americans of both genders and diverse ethnicities. Chen says most clinical trials in America have historically studied only Caucasian males, and many supplement clinical trials are conducted overseas, where the population’s genetics, lifestyles and environment do not look like ours.
- Third-party testing: Look for third-party verification of the product’s quality and safety (such as cGMP, USP, NSF and CLP certifications). These third-party certifications show the product is manufactured under quality practices and tested to be pure and free of contaminants.
Ashwagandha forms and their effectiveness
Ashwagandha comes in various forms, including powder capsules, tinctures and gummies. According to Youssouf, the type of supplement you use may impact its effectiveness.
The doctor offers the following breakdown of popular ashwagandha supplement types:
Capsules: Capsules offer a convenient and consistent way to take ashwagandha.
Powders: Powders can be mixed into drinks but often have a strong, earthy taste.
Gummies: Gummies can be an easy option for those who struggle with swallowing pills. However, they often contain added sugars or artificial ingredients, so it’s important to check the label for purity and potency.
Finally, Youssouf offers, “When choosing an ashwagandha supplement, it is best to look for one that specifies the standardized withanolide content, usually ranging from 1.5% to 5%, and has been third-party tested to ensure quality and safety.”
Potential ashwagandha benefits
Research suggests that ashwagandha may help reduce stress and anxiety by lowering cortisol levels, Youssouf says. “Many people find that taking ashwagandha over time helps them feel calmer, more focused and better able to handle daily stressors,” he says. In addition to those potential benefits, Youssouf says ashwagandha may help you sleep better by supporting relaxation and reducing restlessness. However, results can vary from person to person, and more robust clinical trials are still needed to confirm long-term effectiveness.
Ashwagandha has also been studied for its effects on physical health and performance. A 2024 study published in the National Library of Medicine explored the effects of ashwagandha when taken during resistance training. The study found that participants who took a root ashwagandha supplement for eight weeks saw improvement in muscle strength, growth and endurance.
Youssouf says ashwagandha supplements may also enhance recovery after exercise and reduce inflammation. “Emerging research also suggests that ashwagandha may support immune function, balance blood sugar levels and contribute to heart health, though more studies are needed to confirm these potential benefits,” he says.
A systematic review of 24 studies conducted in 2020 may offer further insight into the relationship between ashwagandha and blood sugar. The review found that ashwagandha “restored the altered levels of blood glucose, glycosylated hemoglobin (HbA1c), insulin, lipid profile, serum and oxidative stress markers” in diabetes patients. It’s worth noting the review echoes what Youssouf said: More robust research is needed to prove this connection.
“In both human and animal studies, ashwagandha consistently exhibits anti-stress and anti-anxiety effects,” Chen says. To learn more, the doctor’s own organization researched ashwagandha root. Radicle Science conducted a randomized, double-blind, placebo-controlled six-week clinical trial with 499 American men and women (21% of whom identified as racial minorities). Chen explains that the study evaluated “600mg of KSM-66 ashwagandha root extract (which is standardized to 5% withanolides), combined with 400mg of reishi mushroom.”
The results were intriguing:
- Those who received this botanical combination showed significantly greater improvements in stress than the group taking a placebo.
- Reported side effects were mild, with no significant differences between the product and placebo group.
Ashwagandha side effects and risk factors
Ashwagandha is generally well-tolerated by most people. According to the National Institutes of Health, in studies where people take the herb for at least three months, most people only experience mild side effects, if any.
The NIH says common side effects include:
- Stomach upset
- Nausea
- Loose bowel movements
- Drowsiness
- Increased heart rate
“While ashwagandha is generally considered safe for most people, some individuals should avoid it or use caution,” Youssouf says. “Pregnant [women] should not take ashwagandha, as it has been linked to uterine contractions and could increase the risk of miscarriage. People with autoimmune diseases, such as rheumatoid arthritis, lupus or multiple sclerosis, should also be cautious because ashwagandha may stimulate the immune system and potentially worsen symptoms.”
The NIH also warns that people with pre-existing liver conditions may want to exercise more caution than others when taking ashwagandha. Recent findings have associated ashwagandha with potential liver damage in some individuals. Therefore, consulting a health care provider before starting any supplement regimen is crucial.
Individuals with thyroid disorders should consult a doctor before taking ashwagandha, Youssouf says. He says the root herb may increase thyroid hormone levels, which may not be suitable for those with hyperthyroidism or those taking thyroid medications. Likewise, if you’re on blood pressure medication, talk to your doctor before taking this supplement because it could lead to dizziness for you.
Ashwagandha dosage
In 2022, an international task force from the Canadian Network for Mood and Anxiety Treatment and the World Federation of Societies of Biological Psychiatry offered a provisional recommendation for ashwagandha dosage. The task force says 300mg to 600mg of ashwagandha root extract (with 5% withanolides standardization) is appropriate for treating generalized anxiety disorder. However, more research is needed.
“Start with a lower dose and gradually increase it to assess how your body responds,” Youssouf says. “Taking ashwagandha with food can help minimize potential stomach discomfort. Since some people find it has a mild sedative effect, taking it in the evening may benefit those using it to improve sleep.”
When to contact a doctor for ashwagandha
It’s wise to check with your doctor before you start an ashwagandha regimen. “It is important to note ashwagandha has an extensive list of other drug interactions, including sedatives and medications for thyroid hormones, diabetes, hypertension, seizures and immunosuppression,” Chen says. “It is important to check with your doctor for contraindications before starting any supplement.”
Amelia Ti, a registered dietitian and diabetes educator in New York City, who is also a member of CNET’s medical review board, adds, “Note that many people that use ashwagandha also take multiple other dietary supplements. Taking multiple supplements without medical supervision can strain your liver or lead to unexpected interactions.”
If you experience any itchiness, lethargy, jaundice, abdominal pain, dizziness or other troubling symptoms, stop taking ashwagandha and contact your doctor.
The bottom line
Ashwagandha may be a powerful agent against everyday stress, insomnia and a host of other medical issues. However, while some studies suggest a relationship between the root herb and things like lowered anxiety, more research is needed. Be mindful of the ingredients in any supplement you take, and consult your doctor before starting a new supplement, especially if you’re already on medications.
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