Short courses for illness or a confirmed low level. Long high doses deplete copper.
What the evidence supports: correcting deficiency and shortening colds if started early.
This scores how well-supported the claim above is — not how much benefit you personally would get. A high score on a narrow claim does not extend to everything the product is marketed for.
Days to weeks for illness; a few months for confirmed deficiency. Not a permanent addition.
People with poor appetite, recurrent infections, plant-based diets, or documented low levels.
Other supplements:
Run your full list through the interaction check.