man touches neck, supplements swirl around his head

Ashwagandha and Thyroid Health: Can an Herb Help Your Hormones?

The herb may help some thyroid conditions, but exacerbate others.

Our product picks are editor-tested, expert-approved. We may earn a commission through links on our site.

People often turn to the adaptogenic herb ashwagandha to help alleviate stress (1), or boost testosterone levels (2). But research suggests there’s also a link between ashwagandha and thyroid health, specifically for hypothyroidism (3).

Ashwagandha may directly help regulate thyroid hormone levels, says Rosia Parrish, N.D., a functional medicine practitioner. “By managing stress and reducing cortisol levels, ashwagandha may also indirectly support thyroid health, as chronic stress can be a contributing factor to thyroid imbalances.”

If your doctor approves its use, should it be part of your treatment plan, in addition to traditional medicine? Here’s what to know about ashwagandha and thyroid health.

What Is Ashwagandha?

Ashwagandha is the Sanskrit name for Withania somnifera (L.), a shrub found in parts of Africa, Asia, and Europe. It means “wet horse,” referring to the smell of the plant’s roots, and it’s been used in traditional Ayurvedic and Unani medicine systems of India (4).

The herb is available in capsules, powders, and liquid extracts, and is believed to help with several different areas of your health. For instance, research suggests it may reduce stress and anxiety and help with sleep (4). 

But, “its primary influence lies in its ability to regulate thyroid hormone level,” Parrish says. 

About the Experts

Rosia Parrish, N.D., a functional medicine practitioner in Boulder, Colorado, who offers naturopathic support for those with gut health issues, such as SIBO, IBS, and food sensitivities. She also specializes in autoimmune conditions and hormonal imbalances for both men and women.

Natalie Kunsman, M.D., an integrated health advisor and physician at Broad Health, Hone Health’s partnered medical practice. She specializes in functional, anti-aging, and regenerative medicine.

Nathan Goodyear, M.D., M.D.H., an integrative doctor at Brio-Medical Cancer Clinic in Scottsdale, Arizona, who specializes in holistic therapies for disease prevention and resolution. 

How Might Ashwagandha Impact Thyroid Health?

Ashwagandha may help regulate your body’s levels of thyroid stimulating hormone (TSH), which is produced by the pituitary gland. Producing too much TSH can be a sign that your body isn’t producing enough T3 and T4, or hormones that collectively make up thyroid hormone (5). Research suggests that ashwagandha can help normalize T3 and T4 levels in people with elevated TSH levels (3).  

Ashwagandha’s stress-lowering effects may also have a positive effect on thyroid health. The herb appears to impact the hypothalamic pituitary adrenal (HPA) axis, your body’s main stress response system. (6, 7). 

“Ashwagandha’s adaptogenic properties play a role in balancing the hypothalamic-pituitary-adrenal (HPA) axis, which is interconnected with thyroid function,” says Parrish.

Part of your endocrine system, the HPA axis controls how much cortisol—the stress hormone—should be produced by the adrenal glands (8). 

Chronic stress jacks up cortisol levels, leading to lower levels of T3 and T4. By lowering cortisol, ashwagandha gives these same hormones a boost (3).  

That said, the benefits of ashwagandha aren’t the same for all types of thyroid disorder. For instance, people with hypothyroidism may benefit from it—while those with hyperthyroidism should avoid it.

Ashwagandha and hypothyroidism 

If you have hypothyroidism, your thyroid gland doesn’t produce enough T3 and T4. This can affect your entire body and slow down metabolism, according to the Cleveland Clinic (9). Extremely low thyroid levels can lead to symptoms like anemia, confusion, and a low body temperature. 

Hypothyroidism is usually treated with medications like levothyroxine, which helps boost how much thyroid hormone you make. But ashwagandha may also help to increase hormone production. “Ashwagandha may help by stimulating the thyroid gland to increase hormone production,” says Parrish. “This is primarily due to its active compounds, like withanolides, which enhance thyroid function.” 

In one 2018 study, eight weeks of treatment with ashwagandha root extract improved blood levels of three types of thyroid hormones over an eight-week period (3).

Ashwagandha and hyperthyroidism

Hyperthyroidism is when the thyroid gland makes too much hormones (10) leading to symptoms including irritability, fatigue, muscle weakness and trouble tolerating heat. 

Ashwagandha is not recommended for people with an overactive thyroid because it may stimulate the thyroid to produce more hormones, says Parrish. “It might exacerbate the already high hormone levels in hyperthyroidism, leading to worsening of symptoms like anxiety, rapid heartbeat, and weight loss,” Parrish says. 

How to Use Ashwagandha for Hypothyroidism

“I would only recommend use of ashwagandha under care of a provider—and would not recommend anyone try to manage thyroid health without supervision,” says Natalie Kunsman, M.D

However, if your doctor approves it, it’s fairly easy to find high-quality ashwagandha supplements. Here are some things to consider when purchasing ashwagandha. 

Ashwagandha can be taken in capsule, powder, or liquid extract.. Make sure you follow your doctor’s recommendations about dosage (it can vary quite a bit between products). 

Experts also emphasize purity and quality when it comes to choosing supplements. Make sure your supplements are certified organic and free from additives, fillers, and allergens you’re sensitive to. 

“Any supplement company that will not provide you with quality assurance documentation upon request is probably a source to avoid,” says Nathan Goodyear, M.D., M.D.H. “Contamination of medications and supplements today is a growing contributor to poor health today.” 

When in doubt, ask your doctor for their recommendation or look for organizations that verify the quality of products, such as USP, NSF, and Third-party groups like these can help you check the quality of certain supplements, since the Food and Drug Administration doesn’t verify supplements for quality.

Can I take ashwagandha with thyroid medicine? 

If your doctor green lights adding the herb to your treatment protocol, they’ll likely want to monitor your labs.

“I would treat ashwagandha like any medication and monitor its use with bloodwork,” Kunsman says.

Possible adverse effects of ashwagandha

“Ashwagandha is typically well tolerated across a spectrum of body types, metabolic dysfunction, and disease states,” says Goodyear. Still, you might experience mild to moderate side effects which can include (4):

  • Gastrointestinal upset
  • Loose stool or diarrhea
  • Nausea or vomiting 
  • Feeling drowsy or sleepy
  • Possible allergic reactions 


If you’re pregnant or breastfeeding women, or have an autoimmune disease or severe medical condition, your doctor may recommend avoiding ashwagandha.

“For those with autoimmune diseases, such as rheumatoid arthritis, lupus, or Hashimoto’s thyroiditis, ashwagandha might exacerbate symptoms due to its immunomodulating effects,” says Parish. “Ashwagandha may also lower blood sugar levels and blood pressure, which could be a concern for people with diabetes or hypotension, or those taking medications for these conditions.”

Best Ashwagandha Supplements 

If your doctor is on board with ashwagandha, our experts recommend these picks:

The Bottom Line

Research suggests that ashwagandha may help treat hypothyroidism but not hyperthyroidism. The herb may also help regulate other hormones in the body, as well. As with any supplement, talk to your doctor before taking it and buy from expert-recommended sources.