I'm not sure about any internal pain relievers....I've done waxing professionally in the past and the best thing I can recommend is a topical with lidocaine (sp?) about 30 mins prior to waxing. That way any residue from the lotion can be wiped away and the medication will have soaked in already. I've also found that the more an area is waxed, the less sensitive it is. It's something you have to keep up though, if you wait till all the hair grows back and just get waxed infrequently the tolerance won't build up the same way. Good luck!