Being a fan of natural products in general and Tom's of Maine in particular, I was expecting a pleasant experience with their lavender deodorant after a nice experience with their unscented version. The ingredients were refeshingly aluminum-less, and the scent was nice and subtle. Unfortunately, its effect on my armpits was not.
I have rather sensitive skin, and after a few days of using the deodorant, I noticed a dark ring starting to form on the sensitive skin of my armpit. I thought it was strange, but didn't think anything of it. Until my armpits started to itch so voraciously that I couldn't not scratch them, even in the most public of places. I inspected my armpits once again, and realized that the skin there was peeling like a bad sunburn. I discontinued use immediately.
The obvious answer would be an allergy to lavender, but strangely enough, I have none. I grow lavender, and own lavender essential oil, and have never experienced anything quite so heinous as the darkening, peeling effect this deodorant had on my armpits. I've started using baking soda instead, and while not quite as glamourous, I no longer have peeling 'pits.