Hi Erika -
Thank you for your question. The area around the brows may be red because you are invigorating the area with the spoolie brush. Or, your skin may be sensitive to the formula. Can you tell us approximately how long the area remains red and to what degree? If it's a superficial or temporary response, that should not be an issue. If you find that this is persistent and problematic, please stop using the serum and consult with your physician.
NULASTIN uses naturally derived, naturally sourced ingredients. All formulas are paraben-free, top allergen-free, clinically evaluated, and proven safe.