For me, it was my MH nurse who noticed the change first (Although he did not tell me until I figured it out on my own). I noticed a difference two weeks after he did. I was calmer, my head was less foggy, my sh and sui thoughts dropped in frequency, I was sleeping well, I felt slightly more capable. Some things haven't changed for me though, l still don't take daily showers, go out of the house much, engage with the world and I'm still escaping through sleep and my addiction.
So ... Some things have noticeably changed and I feel generally better, but there are some things it doesn't help or work for.