Hypothyroidism / Hashimoto’s patients find that they often don’t feel 100% even after standard treatment with medication. Quite often, they find that while their symptoms may have improved somewhat, they still feel tired/lethargic, still feel cold, still feel “down”, or that they still can’t get their weight down. While it is always a good idea to try to get to the “root cause” of the issue with a knowledgeable medical practitioner, natural alternative treatment options can really help these people feel better on a daily basis and further improve their thyroid hormone levels.

If you have already switched to Naturoid or a similar desiccated thyroid (as discussed in the Introduction to Hypothyroidism), had some symptom improvement, but still are not to the level you want to be, then ashwagandha may be able to help you. Alternatively, if you have “sub-clinical” hypothyroidism in which your lab values indicate slight hypothyroidism but not severe enough to treat with medication or without symptomatology (such as weight gain), then ashwagandha may be able to help you as well.

The following is not medical advice for you as an individual. It is for informational purposes only and can be discussed with your medical doctor if you are interested.

Ashwagandha is an herb that is usually classified as an “adaptogen”. When people say this, they mean that it has been shown to protect from a wide variety of stressors and insults to the body (and thus, can improve stress levels and sometimes anxiety). (1) This herb has been used in Ayurvedic medicine for centuries and has a good safety profile if you have a good source.

When people say “adaptogen”, they could also mean that the nutraceutical helps to bring lab values closer to “normal”. Thus, an adaptogen should raise low cortisol and lower high cortisol, for example. However, there is one area where ashwagandha is certainly NOT an adaptogen in this regard: thyroid hormones.

It was first shown in rodent studies that large doses of ashwagandha root extract increased both T4 and the active thyroid hormone T3 significantly in normal mice. (2) At the same time, the extract decreased lipid peroxidation, which is a good thing because having too much thyroid can increase lipid peroxidation due to an increase in free radical production.

Later on, researched happened to notice that when they were treating some of their bipolar patients with ashwagandha to help with their psychological issues, their T4 blood values tended to go up and their TSH levels went down (a sign typically of more thyroid hormone in the blood). In fact, one patient that started out with subclinical hypothyroidism moved into “normal” during the treatment. (3)

This preliminary rodent and human data must have made some researchers curious, because in 2018 they decided to test ashwagandha on patients with subclinical hypothyroidism. This is important because the previous data that I had mentioned had all been tested in “normal” mice and humans (except for a couple in the bipolar study). Subclinical in this study means “a thyroid disorder [TSH ~ 4.5–10 μIU/L] without obvious symptoms of thyroid deficiency”. Often, subclinical hypothyroidism can progress into overt hypothyroidism if left untreated.

In this 2018 study, researchers used a small, but powerful, ashwagandha extract of 600 mg a day. The exact extract they used was “KSM-66 Ashwagandha (a 100% aqueous extract of Withania somnifera roots, containing 5% withanolides as estimated by HPLC)”. The two more powerful and standardized extracts on the market currently are KSM-66 and Sensoril. Sensoril actually contains a higher amount of active compounds, but since the only human study we have used KSM-66, this is what I would recommend for anyone interested in trying this herb. KSM-66 can be found at various places like Amazon.

After 8 weeks of having the patients take the KSM-66 ashwagandha, the researchers concluded,

“Eight weeks of treatment with ashwagandha improved serum TSH (p < 0.001), T3 (p = 0.0031), and T4 (p = 0.0096) levels significantly compared to placebo. Ashwagandha treatment effectively normalized the serum thyroid indices during the 8-week treatment period in a significant manner (time-effects: TSH [p < 0.001], T3 [p < 0.001], and T4 [p < 0.001]).”

Effect of Ashwaganda on thyroid function

This means that the results were highly statistically significant, TSH decreased, and the thyroid hormones T4 and T3 increased. (4)

While this is the first double-blind study to show that ashwagandha reliably increases thyroid function in subclinical hypothyroid patients, and thus should be taken with caution, it is in line with previous animal and human data as detailed above.

This, along with the overall lack of negative side effects, makes ashwagandha a very interesting option for patients with this condition.

While there is no published human data that ashwagandha will be effective in patients with Hashimoto’s disease, it may be a good herb to trail on an individual basis. It is very important to note, though, that should not go at this alone without your doctor’s supervision. This herb will likely change your hormone levels. Thus, if you are medicated, your medication dose may need to be lowered after a certain number of weeks to make sure that you do not go into the hyperthyroid range.

Also, they used 600mg per day in the study above. Animal studies suggest that Ashwaganda has a dose response curve, meaning higher doses will likely raise thyroid hormones more.

Please talk to your doctor before beginning any new supplementation. This is especially important for herbs that have an impact on hormone levels.

Click here to see which brand of Ashwaganda I recommend!

As always, let me know if you have any comments, questions, or experiences below! I would love to hear from you!


  1. Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian J Psychol Med. 2012;34(3):255-62.
  2. Panda S, Kar A. Changes in thyroid hormone concentrations after administration
    of ashwagandha root extract to adult male mice. J Pharm Pharmacol. 1998
    Sep;50(9):1065-8. PubMed PMID: 9811169.
  3. Gannon JM, Forrest PE, Roy chengappa KN. Subtle changes in thyroid indices during a placebo-controlled study of an extract of Withania somnifera in persons with bipolar disorder. J Ayurveda Integr Med. 2014;5(4):241-5.
  4. Sharma AK, Basu I, Singh S. Efficacy and Safety of Ashwagandha Root Extract in
    Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled
    Trial. J Altern Complement Med. 2018 Mar;24(3):243-248. doi:
    10.1089/acm.2017.0183. Epub 2017 Aug 22. PubMed PMID: 28829155.

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