May shorten colds if started within 24 hours. Days, not weeks.
What the evidence supports: shortening cold duration when started within 24 hours.
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.
Up to about a week from symptom onset.
Adults at the very start of a cold.
Other supplements:
Run your full list through the interaction check.