mineralNot FDA-approvedOTC supplementThe cited trial is a small pilot study in a mildly iodine-deficient Swedish cohort
IodineBenefits, Dosage & Interactions
Iodine is an essential trace mineral that is crucial for human health, primarily known for its role in thyroid hormone production. The body does not produce iodine, so it must be obtained through diet. Research on Iodine focuses on cognition and mood.
How much Iodine do people take?
The cited pilot randomized trial used iodine 150 mcg/day supplementation from early pregnancy through 6 months postpartum. Route reported: Oral. Frequency reported: Daily in the cited trial. These are amounts documented in the cited studies and labels for Iodine — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Moderate — One published human randomized trial; results not yet replicated.
Evidence strengthModerate · 3/4
PreclinicalStrong human evidence
One published human randomized trial; results not yet replicated.
Whole-body biological half-life
Not applicable
Typical timing
in the morning
Default unit
mcg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Reported amounts
- The cited pilot randomized trial used iodine 150 mcg/day supplementation from early pregnancy through 6 months postpartum[1]
- Route studied
- Oral[1]
- Frequency
- Daily in the cited trial[1]
- Cycle length
- From early pregnancy through 6 months postpartum in the cited trial[1]
- Half-life
- Not applicable; iodine is an essential mineral[1]
- Storage
- Room temperature, sealed[1]
Reported for Iodine in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Iodine entry is written from. Each number matches an inline marker above.
- [1]A randomized, double-blind study of iodine supplementation during pregnancy in Sweden: pilot evaluation of maternal iodine status and thyroid functionManousou S, Andersson M, Eggertsen R, et al. · European Journal of Nutrition · 2021 · Peer-reviewed · PMID 33620551
References & Evidence
Sources on this page that document Iodine dosing, timing and safety.
- [2]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Iodine studied for?
What is Iodine?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Iodine is an essential trace mineral that is crucial for human health, primarily known for its role in thyroid hormone production. The body does not produce iodine, so it must be obtained through diet. Thyroid hormones, namely thyroxine (T4) and triiodothyronine (T3), regulate many important biochemical reactions, including protein synthesis, enzymatic activity, and metabolic rate. They are also critical for skeletal and central nervous system development in fetuses and infants (NIH ODS, Iodine Fact Sheet for Health Professionals). Around 70-80% of the body's iodine is found in the thyroid gland. Iodine deficiency can lead to a range of health issues, including goiter (enlargement of the thyroid gland) and hypothyroidism. Globally, iodine deficiency is a significant public health problem, particularly in regions where dietary intake is low (World Health Organization). As a result, many countries have implemented universal salt iodization programs to ensure adequate intake. Excess iodine intake can also be detrimental, leading to thyroid dysfunction, including both hypothyroidism and hyperthyroidism, highlighting the importance of maintaining an appropriate balance.
What does the research say about Iodine?
Tap a section to expand.
Iodine's primary mechanism of action revolves around its incorporation into thyroid hormones. After ingestion, iodine is absorbed in the gastrointestinal tract and then transported to the thyroid gland via sodium-iodide symporters (NIS) located on the thyroid follicular cells. Once inside the thyroid cells, iodide is oxidized to iodine by the enzyme thyroid peroxidase (TPO). This active iodine then iodinates tyrosine residues on thyroglobulin, a large glycoprotein synthesized within the thyroid gland. The iodinated tyrosines then couple to form monoiodotyrosine (MIT) and diiodotyrosine (DIT), which are precursors to thyroid hormones. Through further enzymatic action, MIT and DIT combine to form T3 (one MIT and one DIT) and T4 (two DITs). These hormones are stored within the thyroid follicles bound to thyroglobulin and are released into the bloodstream as needed, regulated by thyroid-stimulating hormone (TSH) from the pituitary gland. T3 is the more active form of the hormone, while T4 is primarily a prohormone that is converted to T3 in peripheral tissues. These thyroid hormones exert their effects by binding to nuclear receptors in target cells, influencing gene expression and thereby regulating a wide array of metabolic and developmental processes throughout the body (NIH ODS, Iodine Fact Sheet for Health Professionals).
Source for this section: Sources for How does Iodine work?: Jumps to this entry in the sources and references list at the end of the page.
The most significant benefit of adequate iodine intake is the maintenance of normal thyroid function and the prevention of iodine deficiency disorders. These benefits include:
* **Thyroid Hormone Production:** Iodine is an indispensable component of thyroid hormones (T3 and T4), which are vital for regulating metabolism, energy production, body temperature, and growth. (NIH ODS, Iodine Fact Sheet for Health Professionals)
* **Metabolic Regulation:** Thyroid hormones influence the metabolic rate of almost all cells in the body, impacting how efficiently the body uses energy from food. (MedlinePlus, Thyroid hormones)
* **Fetal and Infant Development:** Adequate iodine during pregnancy and infancy is critical for proper neurological development and brain maturation. Severe iodine deficiency during these periods can lead to irreversible intellectual disability (cretinism). (NIH ODS, Iodine Fact Sheet for Health Professionals)
* **Cognitive Function:** Normal thyroid function supported by sufficient iodine is associated with healthy cognitive function, including memory and learning in children and adults. (Cochrane Review, Iodine supplementation for the treatment of iodine deficiency in women of reproductive age)
* **Growth and Development:** Beyond neurological development, thyroid hormones are essential for normal physical growth and development throughout childhood and adolescence. (NIH ODS, Iodine Fact Sheet for Health Professionals)
* **Prevention of Goiter:** Iodine deficiency is the leading cause of goiter, an enlargement of the thyroid gland. Sufficient iodine intake prevents the thyroid from overworking in an attempt to capture more iodine from the bloodstream. (Mayo Clinic, Goiter)
Source for this section: Sources for What is Iodine used for?: Jumps to this entry in the sources and references list at the end of the page.
Evidence for the importance of iodine is extensive and well-established. The role of iodine in thyroid hormone synthesis was identified in the early 20th century. Universal salt iodization programs, initiated in many countries, have consistently demonstrated their effectiveness in reducing the prevalence of iodine deficiency disorders (IDD). For example, a 2017 review by the Cochrane Library highlighted that iodine supplementation significantly improved thyroid function in iodine-deficient women of reproductive age. The World Health Organization (WHO), UNICEF, and the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) actively promote and monitor salt iodization programs globally due to the robust evidence of their public health benefits. Studies consistently show that regions with adequate iodine intake have significantly lower rates of goiter, hypothyroidism, and cognitive impairment compared to iodine-deficient areas (NIH ODS, Iodine Fact Sheet for Health Professionals). Furthermore, research continues to refine our understanding of optimal iodine intake, especially for vulnerable populations such as pregnant and lactating women, where specific recommendations are provided by health organizations.
Source for this section: Sources for How strong is the evidence for Iodine?: Jumps to this entry in the sources and references list at the end of the page.
While generally safe at recommended dietary intake levels, both insufficient and excessive iodine can cause side effects. Side effects associated with excessive iodine intake include:
* **Thyroid dysfunction:** Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can result from chronic high iodine intake. This is particularly true for individuals with pre-existing thyroid conditions or those living in iodine-deficient areas who are suddenly exposed to high iodine levels. (NIH ODS, Iodine Fact Sheet for Health Professionals)
* **Goiter:** Paradoxically, very high iodine intake can also lead to goiter, as it can inhibit thyroid hormone synthesis. (PubChem, Iodine)
* **Thyroiditis:** Inflammation of the thyroid gland.
* **Iodism:** Symptoms can include acne-like skin lesions, headache, metallic taste in the mouth, increased salivation, and gastrointestinal upset (nausea, diarrhea). (DrugBank, Iodine)
* **Allergic reactions:** Though rare, some individuals may experience allergic reactions, such as skin rash, hives, fever, or joint pain. (FDA label for specific iodine-containing products)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Individuals with certain medical conditions should exercise caution or avoid iodine supplementation. It is crucial to consult a healthcare professional before taking iodine, especially if you have:
* **Pre-existing thyroid disease:** Including Hashimoto's thyroiditis, Graves' disease, or nodular goiter. Iodine intake can exacerbate these conditions or induce thyroid dysfunction. (NIH ODS, Iodine Fact Sheet for Health Professionals)
* **Dermatitis herpetiformis:** A chronic blistering skin condition, which can be worsened by iodine. (MedlinePlus, Dermatitis herpetiformis)
* **Sensitivity to iodine:** A history of allergic reactions to iodine-containing products, including iodine-based contrast dyes. (FDA label for specific iodine-containing products)
* **Kidney disease:** Individuals with impaired kidney function may have difficulty excreting excess iodine. (DrugBank, Iodine)
Pregnant and breastfeeding women should ensure adequate, but not excessive, iodine intake as recommended by their healthcare provider, as both deficiency and excess can harm the fetus or infant. Iodine supplements should be used with extreme caution in children, always under medical guidance. People living in areas where universal salt iodization is already in place may be at higher risk of excessive intake if they also use iodine supplements.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Iodine is contraindicated in individuals with known hypersensitivity to iodine. It should be used with extreme caution, or not at all, in patients with established thyroid disorders such as active Graves' disease, Hashimoto's thyroiditis, or autonomously functioning thyroid nodules, unless specifically directed and monitored by an endocrinologist due to the risk of inducing or worsening thyroid dysfunction. Furthermore, it is generally contraindicated in individuals with dermatitis herpetiformis or hypocomplementemic vasculitis.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Iodine can interact with certain medications and other compounds. Consult your healthcare provider before combining iodine with:
* **Antithyroid medications:** Such as methimazole and propylthiouracil, used to treat hyperthyroidism. Iodine can interfere with their efficacy and may exacerbate hyperthyroidism. (DrugBank, Iodine)
* **Lithium:** Used to treat bipolar disorder. Combining lithium with iodine can increase the risk of hypothyroidism and goiter. (DrugBank, Iodine)
* **Potassium-sparing diuretics:** Such as spironolactone or amiloride. These drugs can increase potassium levels, and high doses of iodine (especially potassium iodide) can further elevate potassium, leading to hyperkalemia. (DrugBank, Iodine)
* **ACE inhibitors (Angiotensin-Converting Enzyme inhibitors):** Including enalapril, lisinopril. Similar to potassium-sparing diuretics, these can also increase serum potassium levels, enhancing the risk of hyperkalemia when combined with high doses of iodine (specifically potassium iodide). (DrugBank, Iodine)
* **Thyroid hormones:** Supplementing with exogenous thyroid hormones while also taking iodine can disrupt the delicate balance of thyroid function, requiring careful monitoring. (Mayo Clinic, Thyroid disease)
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
For general supplementation, iodine is typically taken in the morning. It can be taken with or without food. Specific dosing should always be user-directed and set by a licensed clinician based on individual needs and deficiency status. For conditions like severe iodine deficiency or certain medical diagnoses, a clinician may recommend specific dosage timings.
Source for this section: Sources for When should you take Iodine?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Iodine is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Iodine?
No interaction rules currently on file for this compound in DoseRoutine.
Frequently asked questions about Iodine
The primary role of iodine is to serve as a critical component in the synthesis of thyroid hormones (thyroxine and triiodothyronine). These hormones are essential for regulating metabolism, energy production, growth, and neurological development (NIH ODS, Iodine Fact Sheet for Health Professionals).
Many people can get enough iodine from their diet through sources like iodized salt, seafood (fish, seaweed), dairy products, and eggs. However, dietary intake can vary significantly, and in some regions, iodine deficiency is common. Universal salt iodization programs aim to ensure adequate intake (NIH ODS, Iodine Fact Sheet for Health Professionals).
Excessive iodine intake can lead to various adverse effects, including thyroid dysfunction (both hyperthyroidism and hypothyroidism), goiter, and symptoms of iodism (such as a metallic taste, rash, or gastrointestinal upset). It's important to stick to recommended daily allowances or clinician-directed doses (NIH ODS, Iodine Fact Sheet for Health Professionals).
Adequate iodine intake is crucial during pregnancy for fetal brain development. However, both deficiency and excessive intake can be harmful. Pregnant women should consult their healthcare provider for specific recommendations on iodine intake, often through prenatal vitamins containing iodine, to ensure optimal levels (NIH ODS, Iodine Fact Sheet for Health Professionals).
Iodine deficiency is typically diagnosed through urine iodine concentration tests, although these can reflect recent intake rather than long-term status. A swollen thyroid gland (goiter) can be a visual sign of deficiency. If you suspect an iodine deficiency, consult a clinician for appropriate testing and diagnosis (NIH ODS, Iodine Fact Sheet for Health Professionals).
Interaction risk for Iodine comes from the rest of the stack: other minerals, prescription medicines, hormone therapy and peptides. Because Iodine is usually taken in the morning, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Iodine with no sign-up.
Iodine is typically taken in the morning. Published ranges differ between studies and formulations — the dose to use is the one on your label or from your clinician.
There is no single answer for Iodine plus TRT. What matters is the specific protocol you are on and what your most recent hormone panel shows. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Pairing Iodine with peptides has to be assessed one peptide at a time, because GLP-1 agonists, secretagogues, healing peptides and melanocortins do not share an interaction profile. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Iodine varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken in the morning. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Iodine depends on the protocol and formulation you are on. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Iodine the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
The cited pilot randomized trial used iodine 150 mcg/day supplementation from early pregnancy through 6 months postpartum. Route reported: Oral. Frequency reported: Daily in the cited trial. These are amounts documented in the cited studies and labels for Iodine — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Iodine?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Preoperative Antisepsis with Chlorhexidine Versus Povidone-Iodine for the Prevention of Surgical Site Infection: a Systematic Review and Meta-analysis(opens PubMed in a new tab)World J Surg · 2020 · PMID 31996985 · https://pubmed.ncbi.nlm.nih.gov/31996985/
- 2.Chlorhexidine vs Povidone-Iodine and Incidence of Catheter-Related Infections: A Systematic Review and Meta-Analysis(opens PubMed in a new tab)JAMA Netw Open · 2026 · PMID 41678192 · https://pubmed.ncbi.nlm.nih.gov/41678192/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- NIH Office of Dietary Supplements(opens in a new tab)National Institutes of Health · ods.od.nih.gov/factsheets/Iodine-Consumer/
- PubChem CID 807(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/807
Verify at
Publisher search links for Iodine. These are places to check the information — they are not citations, so they are not numbered.
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- World Health Organization(publisher search, opens in a new tab)World Health Organization · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Iodine?
Plain-text summary, safe to quote verbatim:
Iodine is an essential trace mineral that is crucial for human health, primarily known for its role in thyroid hormone production. The body does not produce iodine, so it must be obtained through diet. Research on Iodine focuses on cognition and mood.
Source: DoseRoutine — https://doseroutine.com/library/iodine
Iodine cheat sheet
DoseRoutine cheat sheet · Mineral
Iodine
Iodine is an essential trace mineral that is crucial for human health, primarily known for its role in thyroid hormone production. The body does not produce iodine, so it must be obtained through diet.
Evidence
Moderate
One published human randomized trial; results not yet replicated.
Studied range
The cited pilot randomized trial used iodine 150 mcg/day supplementation from early pregnancy through 6 months postpartum
Route
Oral
Frequency studied
Daily in the cited trial
Half-life
Not applicable; iodine is an essential mineral
Timing
in the morning
Storage
Room temperature, sealed
Not FDA-approvedOTC supplementThe cited trial is a small pilot study in a mildly iodine-deficient Swedish cohortBrain
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/iodine
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Iodine — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/iodine
What compounds are similar to Iodine?
Others in the mineral category or studied for the same goals.
Which goals is Iodine used for?
Other compounds studied for the same benefits as Iodine.
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