When it comes to thyroid health, people are often searching for natural ways to support their hormonal balance and well-being. Among the herbs that have gained attention is ashwagandha, an adaptogen known for its stress-reducing properties. But can it really make a positive impact on thyroid function? Recent studies shed light on this intriguing possibility. Let's explore the clinical evidence substantiating Ashwagandha’s effects on thyroid health – and look at ONLY human studies because that's most relevant to us. We'll also look at some possible side effects of ashwagandha too. Whether you’re managing subclinical hypothyroidism or simply curious about the herb’s potential and best brands to use, you’ll find insights, cautions, and actionable steps. Let’s dive into the research and discover what it reveals.
The Other Names for Ashwagandha
This herb, which grows extensively in Africa, India, and Middle Eastern countries including Iraq, Isreal, and Egypt, may be listed on Supplement Facts labels by several common names, including:
- Indian Ginseng
- Withania somnifera (its scientific name)
- Indian Winter Cherry
There are several other nicknames, too, that sound a lot like “Ashwagandha.”
Normal Thyroid Hormone Levels
Here are reference values taken from LabCorp's website:
- Thyroid-stimulating hormone (TSH) 0.45 – 4.5 mIU/L
- Total T4: 4.5-12.5 ug/dl
- Total T3: 80-200 ng/dl
- Free T3: (Triiodothyronine): 80 – 200 pg/ml
- Free T4: (Thyroxine): 0.8 -1.8 ng/dl
Note that results from your blood test may vary slightly depending on the lab in which your blood work was analyzed and the time of day your blood work was performed. Additionally, these general items can influence your thyroid blood test results too:
- Time of day: TSH is lowest in the afternoon and higher in the morning
- Menstrual cycle variations: TSH may be lower just before ovulation
- Birth control pills may lead to slightly higher T3 and T4 levels
Ashwagandha May Help Subclinical Hypothyroidism & Thyroid Function
Subclinical hypothyroidism is a condition in which TSH is elevated; however, thyroid hormones like T3 and T4 are usually in the normal range. People with this affliction may not experience classic symptoms of hypothyroidism, such as fatigue, hair loss, or weight gain.
To see if ashwagandha helped this condition, researchers recruited 50 overweight people with subclinical hypothyroidism and split them into two groups: One group took 300 mg of ashwagandha root extract twice a day for 8 weeks, while the other group took a placebo. The specific extract used was KSM-66.
Key Findings:
- TSH levels dropped by nearly 20% in the ashwagandha group.
- T4 levels increased by 20%, and T3 levels surged by a remarkable 41%.
- Placebo group: no significant changes.
- It's not stated whether Ashwagandha promoted weight loss.
While these results suggest that ashwagandha may normalize thyroid function indicators, the study noted that TSH levels remained slightly elevated after the study. In other words, TSH did not return to a normal level. This underscores the importance of interpreting TSH alongside T3 and T4 for a fuller picture of thyroid health.
Ashwagandha Effects on Thyroid Hormones In People with Bipolar Disorder
In this study, researchers analyzed the results of 10 people with a manic-depressive mood disorder. The people took either a placebo or 250 mg of ashwagandha twice daily for 8 weeks. These researchers used a standardized extract of the herb called Sensoril.
Key Findings:
- TSH dropped from 5.7 to 1.6 in one standout individual, bringing the participant’s levels into the low-normal range.
- Other participants showed minimal changes, leaving room for interpretation of ashwagandha’s consistency across individuals.
Setting aside the fact that the study only involved 10 people, a major flaw is that seven took the placebo. In other words, only three subjects took ashwagandha.
Ashwagandha Side Effects For People With Hypothyroidism
While the herb is generally considered safe, raising T3 and T4 hormones opens the possibility that ashwagandha may trigger hyperthyroidism in some people. In one report, a 73-year-old woman with primary hypothyroidism developed hyperthyroidism after replacing her medication with ashwagandha, leading to symptoms including chest pains, heart palpitations (heart rate 173 bpm), elevated blood pressure (121/90) and hair loss.
Another case details what happened to a 62-year-old woman who, after just two months of nighttime use, experienced anxiety, extreme fatigue, weight loss, brain fog, and elevated heart rate, as well as reduced TSH and elevated thyroxine (T4). Laboratory analysis confirmed she developed hyperthyroidism and bordered on anemia. The woman stated she took 1950 mg of ashwagandha (a large dose). But, what makes this case difficult to pin down is that she was also taking estrogen and several other supplements.
Ashwagandha Cautions and Precautions
- Consult your physician/pharmacist beforehand if you take levothyroxine (Synthroid), Armour Thyroid, or compounded thyroid medications.
- Avoid replacing your prescribed thyroid medications with ashwagandha without medical guidance.
- Track your thyroid function comprehensively (TSH, T3, T4) to better understand changes.
- Avoid combining ashwagandha with thyroid medications.
- Exercise caution if you are pregnant or breastfeeding.
- Be mindful when using ashwagandha if you have autoimmune disorders due to the lack of comprehensive research on its effects in such conditions.
- Because of the potential to lower blood sugar, avoid ashwagandha if you take diabetes medications, including metformin and insulin.
- Avoid combining ashwagandha with iodine and black seeds (Nigella satia), which may further raise the risk of hyperthyroidism.
- Because the herb may thin the blood, stop taking it at least two weeks before surgery, including dental procedures.
- This herb has been linked to some cases of liver failure and hepatitis.
- Only purchase quality supplements that are third-party tested for purity. In one report, some brands of ashwagandha were found to contain thyroid hormones.
Trusted Ashwagandha Brands
When Consumerlab independently tested 13 brands of ashwagandha, eight supplements (62%) failed, including those from some very well-known companies! Many failing brands contained significantly less herb than the Supplement Facts label indicated. Here are 4 of the brands that passed independent testing and are worth looking at:
How to Approach Ashwagandha Supplementation
For those considering supplementation:
- Start small: For at least the first week, begin with a low dose, less than a company recommends.
- Monitor symptoms: Watch for signs of hyperthyroidism or adverse reactions. Stop if you notice any.
- Opt for quality: Choose reputable brands to ensure product purity.
- Interactions: Be aware that the more supplements you take, the greater the risk of side effects.
Take Home Message: A Balanced Perspective
Ashwagandha shows some potential for supporting thyroid health, particularly in cases of subclinical hypothyroidism. Its ability to influence T3, T4, and TSH levels is promising, but not all effects are universally positive. Individual variability, potential side effects, and interactions with other supplements and medications must be considered. Collaboration with your healthcare provider is essential if you’re exploring ashwagandha for thyroid function. Remember, holistic health requires a well-rounded approach—no single herb is a cure-all.
What Do You Think?
References
https://pubmed.ncbi.nlm.nih.gov/28829155/
https://pubmed.ncbi.nlm.nih.gov/25624699/
https://pmc.ncbi.nlm.nih.gov/articles/PMC9035336/
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3506409