Safety · Supplement
Selenium: side effects, safety & interactions
Toxic in excess: hair and nail loss, GI and neurological effects. The gap between adequate and harmful is smaller than f
- Overall grade
- Grade C
- Last revised
- 0
- graded outcomes
- 0
- references listed
Assembled by the app from other entries in this library. It adds no evidence of its own — follow the links to the entries it draws on.
The evidence in words
Safety profile
Toxic in excess: hair and nail loss, GI and neurological effects. The gap between adequate and harmful is smaller than for most nutrients.
Interactions to respect
No major interactions are on record for Selenium at typical doses, but tell your clinician about everything you take.
What Selenium is
Selenium is an essential trace mineral incorporated into selenoproteins, including antioxidant glutathione peroxidases and enzymes that activate thyroid hormone. Soil content varies widely, so intake tracks geography.
The honest bottom line
Get enough (a Brazil nut or two), avoid megadosing. The 'antioxidant prevents cancer' pitch failed in trials and high intakes carry real downsides.
Related reading
Entries that share this one's tags or conditions.
- Astaxanthin: side effects, safety & interactionsSafe; harmless slight skin-tone change at high doses.Evidence grade C
- Chaga: side effects, safety & interactionsOxalate load — kidney-stone/injury risk; caution with anticoagulants and diabetes drugs.Evidence grade D
- Glutathione: side effects, safety & interactionsWell tolerated; skin-lightening IV use is a separate, unregulated concern.Evidence grade C
- Iodine: side effects, safety & interactionsHigh doses can induce thyroid dysfunction; kelp supplements deliver erratic, sometimes excessive amounts. Stay near requEvidence grade B
Sources
This entry lists no references of its own — it is assembled from the entries it links to, whose sources are on their pages.
Last revised . A grade is this entry's reading of the evidence, not medical advice.