The AI doesn't make your joints ache. However, using the AI at an unnecessarily high rate to the extent that your estrogen crashes will make your joints ache. You can even make your joints ache with Erase.
Finding the right dose of an AI is based on the individual, the other compounds they're using and the stage of their cycle or PCT.
Adex and Aro are both good. But we need a little more info to know what's going on in your situation.