NutriStack
Ashwagandha and Iodine, a caution.
Ashwagandha may stimulate thyroid hormone production (T4 and T3) via its effects on the HPA axis and direct thyroid stimulation. Combined with iodine supplementation, there is a risk of thyroid overstimulation in susceptible individuals.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
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At a glance
- Substances
- Ashwagandha and Iodine
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 1 source
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. Ashwagandha may stimulate thyroid hormone production (T4 and T3) via its effects on the HPA axis and direct thyroid stimulation. Combined with iodine supplementation, there is a risk of thyroid overstimulation in susceptible individuals.
Mechanism. Ashwagandha's withanolides may stimulate thyroid peroxidase (TPO) activity and increase T4 to T3 conversion via type II 5'-deiodinase. Iodine provides additional substrate for thyroid hormone synthesis.
Recommendation. If you have thyroid disease or are taking thyroid medication, consult your doctor before combining ashwagandha and iodine. Monitor thyroid function tests.
Stack Score
How this pair moves the number.
Effect on the composite score
If both Ashwagandha and Iodine are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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