Patch testing gives me an early signal
A patch test may reveal an obvious reaction before I use the formula all over my face. I follow the directions for where and how long to test.
Test one new product at a time
Keeping the rest of the routine familiar gives me a better chance of understanding exactly how my skin responds.
Treat pain as a warning
Persistent burning, swelling, blistering or worsening irritation is a reason to stop. Significant or continuing reactions belong with a qualified medical professional.