I know someone who took interferon for Hep C. It permanently damaged the nerves in his extremities to the point where he can barely walk and is in constant pain. It changed his personality, and not in a good way.
There are some reports of side effects of varying degree, but in general Harvoni's side effects are extremely mild.
When I did the trial, my physician indicated that in previous trials, patients couldn't reliably distinguish Harvoni from a placebo. My experience aligns with this statement.
While I was on a 24 week trial (longer than most people today) with ribavirin (which is only used with a minority of patients today), I experienced nothing I could directly attribute to the medication. My viral load dropped to undetectable in six weeks, and has remained so since.
The only place I saw them list side effects was when an article for a newer drug argued for it's use. It was the one for those who'd previously tried interferon.They said it had no sides as opposed to Harvonihttp://www.fiercepharma.com/regulatory/updated-zepatier-beat...
They sucked.
Patient compliance was low due to the side effects. From what I've heard, it was like having the flu everyday for duration of treatment.
If you any mental health issues (depression, etc) you couldn't take it since the rate of suicide goes way up.
The new HCV drugs are an amazing breakthrough.