Nobody has made claims about how harmful DXM is or is not. I don't believe it itself is harmful on the liver however. Reviewing my information I only see liver trouble only in people missing the key enzyme required to process DXM and people combining it with other active and inactive ingredients. The most information on DXM harm comes from information on Olney's Lesions that, the last time I checked, had never actually been found in a human after prolonged/intense use of DXM. I believe that places harm in the "theoretical" category. Of course each person has to weigh his own risks.

Combining it with other things is really what causes the most harm on the body. The shear amount of sugar in cough syrup is why I steered away from it. I know exactly of the liver pains you speak of and they were all experienced after using a product that just wasn't clean (syrup, gelcaps). You can experience very unpleasant side effects after frequent/intense use, yes. Other than being completely horrible at the time, I have not seen and have not experienced problems from DXM after stopping use.

I had profound good and bad experiences. It was worth it but I did a heck of a lot of reading before I ever put it into my body.