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FitLine Side Effects & Safety Notes

Updated: Jan 2026. Educational only — not medical advice.

Baseline rule: follow label directions, start low to assess tolerance, and stop if you have a reaction. If you have conditions, allergies, are pregnant/nursing, or take medication, consult a qualified professional.

Common tolerance issues (non-exhaustive)

Niacin flush: what it is (and what it isn’t)

Niacin flush is a common, temporary reaction to niacin (vitamin B3) in some supplements. It can feel like warmth, redness, tingling, or itching. It is usually not an allergy. Duration varies — many people report it fades within minutes to an hour or two. If symptoms are severe, persistent, or include breathing issues, seek medical help.

Who should use extra caution