It is a muscle rub, but it doesn't have capsaicin in it (or however you spell that stuff). That stuff can agitate our nerves to the point of exhaustion, you know the fight or flight thing that we get that ends up dousing us with adrenaline for hours and hours? Theragesic has only Menthol in it, as a warning, it will set your skin on fire! But it doesn't bother the nerves as much, and sitting in front of a fan after putting it on makes it no biggy. You can buy it at Wal-Mart in the pharmacy section right next to ben-gay and icyhot. If you haven't heard of it yet, please look into lowdosenaltrexone.org, you won't be sorry.