Selenium (Selenomethionine)
Mineral
Also known as: L-selenomethionine, Organic selenium
A
Grade A💊 100-200 mcg daily🎯 3 primary uses🔗 3 synergies⚠️ Review warnings
Levels upNutrition+50 pts
Overview
Highly bioavailable organic selenium for thyroid and antioxidant function. Narrow optimal range requires careful dosing.
Primary Uses
Thyroid supportGlutathione systemImmune function
Frequently Asked About Selenium (Selenomethionine)
How much Selenium (Selenomethionine) should I take?
The typical effective range is 100-200 mcg daily. Individual needs vary based on age, body weight, diet, and goals — start at the lower end and adjust based on response. Always consult a healthcare provider before starting a new supplement.
When is the best time to take Selenium (Selenomethionine)?
Any. Consistency matters more than perfect timing — pick a daily anchor (e.g. with breakfast or before bed) and stick with it.
Should I take Selenium (Selenomethionine) with food?
Optional.
Does Selenium (Selenomethionine) interact with medications?
Yes — known interactions include May enhance blood thinners. If you take any prescription medication, talk to your doctor or pharmacist before starting Selenium (Selenomethionine).
What does Selenium (Selenomethionine) pair well with?
Selenium (Selenomethionine) stacks well with Iodine, Vitamin E, and Zinc — these combinations either improve absorption or work synergistically toward common goals.
Who should not take Selenium (Selenomethionine)?
Selenium (Selenomethionine) should be avoided or used with caution by people with High selenium status. Pregnant or breastfeeding women should consult a healthcare provider before use.
What are the side effects of Selenium (Selenomethionine)?
Most people tolerate Selenium (Selenomethionine) well. The most commonly reported side effects are Garlic breath at high doses. Side effects are usually dose-dependent — lowering the dose often resolves them.
Dosage
Typical range
100-200 mcg daily
Timing
Any
With food
Optional
Duration
Don't exceed 400 mcg
Special Populations
Thyroid patients
Research & Studies
Search the literature now
We haven’t curated landmark studies for Selenium (Selenomethionine)yet — one-click into the primary literature here. PubMed (RCTs) is usually the highest-signal starting point.
Search Selenium (Selenomethionine) research
Mechanism of Action
- • Incorporated into selenoproteins
- • Essential for T4 to T3 conversion
- • Supports glutathione peroxidase
Evidence Quality
Evidence Grade A
Well-established for thyroid and antioxidant
Safety & Contraindications
Serious Warnings
- • Toxicity >400 mcg
- • Selenosis
Contraindications
- • High selenium status
Common Side Effects
- • Garlic breath at high doses
Pregnancy & Breastfeeding
Consult healthcare provider
Liver & Kidney Notes
Safe at normal doses
Interactions
💊 Medications
- • May enhance blood thinners
🧪 Supplements
- • Works with iodine
- • Supports vitamin E
🍽️ Food & Alcohol
- • Brazil nuts very high
Stacking & Synergies
Pairs Well With
Avoid Combining With
High-dose C may reduce absorption
Best Goal Synergies
ThyroidAntioxidant
Buying Guide
What to Look For
- • Selenomethionine form
Standardization Markers
mcg content
Adulteration risk
Low
Practical Notes
- • Narrow optimal range
- • One Brazil nut = 70-90 mcg
Tags
mineralthyroidantioxidant
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Last reviewed: June 2026 by the Formulate Research Team. Sources cited above; methodology and scoring criteria published here.
Cite this page
Formulate Research Team. (2026, June). Selenium (Selenomethionine) — Evidence-Based Supplement Guide. Formulate Supplement Encyclopedia. https://app.formulate-health.app/learning/supplements/selenium-selenomethionine
Educational content based on published research and our scoring methodology. Not medical advice — consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.