Well, I have been on AP (doxy) for almost a month. Have definitely been herxing, mostly in my hands, which makes sense, since that is where my disease has been the longest (Raynaud's for 25 yrs). Strange, because my hands have never been really painful, just extremely sensitive to the cold. Now I feel like I have RA in them, they start hurting during the night, waking me up, and are so bad in the mornings that I can't lift, twist or turn anything. But I think they have been better the last 3 days, so maybe I am over the hump.