Why Does Vitamin C Serum Sting My Skin? (And How to Fix It Without Damaging Your Barrier) Vitamin C serum can sting because of its formula, irritated skin, or another product in your routine. Stinging alone does not prove that your skin barrier is damaged, and discomfort is not evidence that vitamin C is working. … Continue reading Why Does Vitamin C Serum Sting My Skin? (And How to Fix It Without Damaging Your Barrier)