You may have heard of the many health benefits of the herb Ashwagandha, also known as Indian Ginseng. Ashwagandha has been used for thousands of years in Ayurveda, the ancient medicine tradition of India [1, 2].
As Western medicine catches up to the wisdom of some of the ancient medical traditions, more and more research is coming out about natural remedies such as Ashwagandha. In fact, pharmacological studies have demonstrated that Ashwagandha contains compounds with anti-inflammatory, antioxidant, anti-cancer, anti-stress, and immune modulating properties [1].
One health problem that Ashwagandha is increasingly being used for is hypothyroidism. More and more supplements seem to be hitting the market that incorporate Ashwagandha in products that aim to boost thyroid health, but is there evidence that this herb can alter thyroid function?
Ashwagandha Thyroid Research
The best available study assessing the effects of Ashwagandha for hypothyroidism was conducted in 2018 by researchers from India. In the study, 50 people with subclinical hypothyroidism were assigned to receive either 600 mg per day of Ashwagandha extract or a placebo for 8 weeks, and thyroid hormone levels were checked before and after the study [3].
It is important to note that since these patients had subclinical hypothyroidism, their thyroid hormone levels were within normal range, but their thyroid stimulating hormone (TSH) levels were elevated outside of what is considered to be normal. TSH is the hormone released from the pituitary gland that tells the thyroid to make more thyroid hormone, and high TSH levels are suggestive of reduced thyroid function [4].
By the end of the study, the results showed that the people who received Ashwagandha had significant improvement in TSH levels while the placebo group’s TSH levels actually worsened over the 8 week study period. Additionally, the Ashwagandha group had better T3 and T4 production compared to the placebo group.
These results are certainly encouraging, and they suggest that Ashwagandha can indeed help to normalize TSH levels and increase thyroid hormone production. Even more importantly, there was no difference in side effects between the Ashwagandha and placebo groups, indicating the herb’s safety over an 8 week period.
How Ashwagandha Affects the Normal Thyroid
You may be wondering if Ashwagandha is safe to take even if you don’t have thyroid issues. Fortunately, a recent study from 2020 investigated this very question. In the study, 80 healthy people with normal thyroid function were given either 600 mg per day of Ashwagandha or placebo for 8 weeks, and the results showed that supplementation with Ashwagandha was safe and did not cause any negative side effects or any harm to thyroid function [5].
Ashwagandha for Overt Hypothyroidism
It is worth noting that cases of overt hypothyroidism, where TSH and thyroid hormone levels are far outside of the normal range, will usually require a thyroid hormone prescription. Currently, there are no studies investigating the interaction between prescription thyroid hormone drugs (such as Levothyroxine) and Ashwagandha. However, according to Drugs.com, there are no medications that are known to interact with Ashwagandha [6]. This does NOT mean that interactions cannot occur, so combining Ashwagandha with prescription thyroid hormone should be done with caution and doctor approval.
If you do take Ashwagandha with prescription thyroid hormone for a period of time and you start to notice symptoms such as rapid heart rate, anxiety, palpitations, heat intolerance and poor sleep, it could be a sign that your thyroid hormone levels are getting too high [7]. If this happens, you may need to have your thyroid prescription adjusted.
Key Takeaways
Overall, there is preliminary evidence that taking Ashwagandha for subclinical hypothyroidism is safe and effective. Given the herb’s long history of safety, it is also likely okay to take along with thyroid hormone medication, but this should be done with caution as there is a small chance that thyroid hormone levels could become too high.
If you do opt to take Ashwagandha to support your thyroid, be sure to take a dose consistent with the above research. Try taking 600 mg per day in two divided doses, including one in the morning with breakfast and one in the evening [8].
If you have subclinical or overt hypothyroidism, you may be interested in checking out my clinic. I help patients with thyroid issues improve their many symptoms, including fatigue, weight gain, constipation, cold intolerance, and much more. I can also help to identify if your symptoms are coming from other causes besides thyroid dysfunction, and potentially help to reduce your need for thyroid medication. Click here to apply to become a patient.