Dr. Squatch Natural Men’s Deodorant – Aluminum Free Natural Deodorant Men with Charcoal & Postbiotics for 72-Hour Odor Protection – Coastal Mist, 2.65oz Stick

I've looked up the ingredients list of a this deodorant: Caprylic/Capric Triglyceride, Manihot Esculenta (Arrowroot) Powder, Stearyl Alcohol, Magnesium Hydroxide, Beeswax (Cera Alba), Butyrospermum Parkii (Shea) Butter, Cocos Nucifera (Coconut) Oil, Triethyl Citrate, Naturally Derived Fragrance, Simmondsia Chinensis (Jojoba) Seed Oil, Jojoba Esters, Charcoal Powder, Tocopherol, Lactobacillus Ferment, Maltodextrin. (source). The most likely cause of the redness is the Magnesium Hydroxide. This ingredient will lift the pH of this deo to values far over 7 (neutral), and it will damage the skin's natural acid mantle (pH approx. 5) in the process. This, BTW, is just how the deo works: BO-causing bacteria can't proliferate a such a high pH. Another plausible cause could be the fragrance.