I had taken Milk Thistle the other day and my ringing had seemed to increase to about where it was when it had initially started. After a day or so, it died down. I tried again, and same result. I thought maybe the effect would be similar to NAC because they both increase the synthesis of glutathione. I can't take NAC any longer, it gave me a bad rash, but I had good results on it otherwise. But I just wanted to offer a heads up. I'm not sure why that happened.