Why Niacin Causes Facial Flushing

A hot, red face after a niacin dose alarms many readers. This page explains what the flush is, how little it can take to start, and when to stop and ask someone qualified.

What the flush feels like

MedlinePlus says that when given as a treatment for people with high cholesterol, niacin supplements can cause flushing, which is a feeling of warmth, redness, itching or tingling of the face, neck, arms or upper chest. Niacin also appears in research on NAD+, and a review of NAD⁺ biology and supplementation is one place to see that link.

How small a dose can start it

Wikipedia reports that at daily doses of nicotinic acid as low as 30 mg, flushing has been reported, always starting in the face and sometimes accompanied by skin dryness, itching, paresthesia, and headache. That figure is low, so a label that looks modest is not a guarantee of comfort. The Vitamin B3 entry gives general background on the vitamin itself.

Why intravenous products need more care

A flush from a capsule is one question. A flush during an infusion is another. Readers weighing that route can start with a guide to NAD+ infusion safety before committing.

A conservative line

Treat flushing as a signal, not a nuisance. If it appears, stop the product and ask a pharmacist or clinician before taking more. If you are considering an infusion, read this pilot study comparing intravenous NAD+ and nicotinamide riboside and then talk to a licensed professional about your own situation.