Personally, for some reason when I do a liver flush, I have no problem sleeping. So I don't take the ornithine then.
If I've been having problems sleeping for a few days, I'll take around 6-8 capsules. I start at 6:00 with 2, 8:00 another two and if I'm not tired, another 2 around 10:00.
I also take some after I do my weekly parasite maintenance. When Dr. clark talks about Ammonia, I didn't know that she was literally talking ammonia. when I first did a parasite cleanse, I could taste ammonia in my mouth and I could smell if everywhere I went. My eyes even had a slight burn. Either the Ornithine fixed it, or I accidentally healed (if I'm being a skeptic) either way, I see in a lot of weight lifting supplements that they use ornithine.
I also have not read her book, but if you go to curezone, you can click on Dr. Clark and get a lot of cool info from her.
Let me know if you try it and if it works. Some claim it works right away (first night) other's claim it takes a few days.