Our read is that iodine supplementation may be beneficial for some individuals, particularly those with dietary deficiencies or specific health conditions, but caution is warranted due to the risks of excessive intake.
◐PARTIALLYSUPPORTED
⚠
High-risk intervention — consult a physician before acting.Drug-drug interactions, dose-dependence, and screening contraindications apply.
Consensus
71%
leaning supportive
Evidence quality
10/100
speculative
Risk
High
specialist only
Cost / month
$
estimated
Effort
Low
time & habit
Abstract
Sufficient iodine intake is essential for healthy thyroid function and metabolic processes, with Andrew Huberman noting its necessity alongside selenium and L-tyrosine for thyroid hormone production.
Iodine deficiency is becoming more common due to reduced intake of iodized salt and can be exacerbated by goitrogenic substances found in certain foods, but excessive supplementation carries significant risks.
While some experts like Bryan Johnson take daily liquid iodine, others like Paul Saladino and Peter Attia warn against high doses due to potential adverse effects on thyroid function and autoimmune thyroid disease.
Method
Bryan Johnson takes 125 mcg of liquid iodine daily. Varying protocols suggest either high doses or around 200 micrograms of iodine per day for appropriate thyroid hormone levels.
Evidence detail
01Andrew Huberman states that sufficient iodine intake is essential for the thyroid to produce thyroid hormone.
02Paul Saladino notes the Recommended Daily Allowance for iodine is 150 micrograms per day.
03Bryan Johnson takes 125 mcg of liquid iodine daily.
04Paul Saladino claims cassava flour contains linamarin, which breaks down into hydrocyanic acid, and also contains isothiocyanates and goitrogenic substances that inhibit iodine uptake at the thyroid.
05Andrew Huberman states that sufficient iodine, selenium, and L-tyrosine intake is necessary for healthy thyroid function and metabolic processes.
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06Paul Saladino notes that omega-3 fatty acids and iodine are essential nutrients primarily found in seafood, but also in other animal parts like egg yolks, bone marrow, and salmon roe.
07Andrew Huberman states that iodine deficiency is becoming more common due to reduced intake of iodized salt, sea salt, and Himalayan salt, potentially contributing to thyroid issues.
08Paul Saladino claims iodine deficiency is frequently observed in indigenous cultures that primarily consume roots and cassava, which are low in iodine and contain goitrogens.
09Andrew Huberman states that iodine supplementation or sufficient dietary iodine intake is associated with reduced levels of C-reactive protein (CRP) and an anti-inflammatory effect.
10Paul Saladino claims high consumption of cruciferous vegetables in Melanesian women with low dietary iodine may contribute to exceptionally high incidence of thyroid cancer.
11Andrew Huberman states that historically, iodine deficiency in inland or mountainous regions led to goiter, characterized by thyroid gland hypertrophy due to overstimulation.
12Andrew Huberman states that approximately 20% of women and 10% of men have low thyroid function, with 50% of these cases undiagnosed, and iodine supplementation may help.
13Andrew Huberman and Paul Saladino state that iodine deficiency is primarily caused by goitrogens like sulforaphane and other isothiocyanates that compete with iodine at the ionic level in the thyroid.
14Paul Saladino states that iodine deficiency is unlikely in individuals consuming a diet rich in animal foods, unless they also consume large quantities of goitrogenic vegetables.
Caveats
Andrew Huberman notes that diets very low in processed foods can lead to low iodine intake, and consuming high amounts of cruciferous vegetables can interfere with thyroid hormone function and increase the need for iodine. Paul Saladino states that iodine can be obtained from raw milk, eggs, and meat, and that broccoli can impair iodine absorption and utilization. Andrew Huberman warns that individuals with hyperthyroidism should not supplement with iodine. Paul Saladino advises that seaweed and kelp contain high amounts of iodine and should not be consumed in excessive quantities, and that supplementing with iodine, particularly Lugol's iodine, can easily lead to excessive intake and potentially toxic levels, causing TSH to rise significantly. Paul Saladino also notes that excessive iodine supplementation above 100-300 micrograms daily can cause adverse thyroid symptoms and that excess iodine intake can be dangerous and was not an evolutionary norm for humans. Peter Attia states that high-dose iodine supplementation (e.g., 500-600 micrograms/day) is associated with an increased incidence of autoimmune thyroid disease, and that iodine supplementation can induce hypothyroidism, particularly in individuals with thyroid nodules, and can trigger autoimmune thyroid disease by increasing thyroid antigenicity. Rhonda Patrick notes that maternal cigarette smoking halves iodine concentration in breast milk, impairing infant brain development and thyroid function.
What would change this verdict
Further research clarifying optimal iodine dosages for various populations, the long-term effects of moderate supplementation, and more precise identification of individuals who would benefit most from supplementation without adverse effects would change the verdict.