Back pain from hell....

So I was using icy hot religiously lately and kinda freaked because I didn't realize it could be bad for baby! Well I took to Dr. Google and after picking everything apart, I came to this conclusion: some icy hot products have aspirin in them, however there are some that do not. Try to stick to a rub that has menthol only. So my question is, does anyone else have any input from a doctor? I have been using this rub and it says menthol is the only ingredient so I'm ASSUMING it's safe. Anyone a nurse/pharmacist/mommy to be with knowledge?!?