When I did my first cleanse, I did not take the ornithine capsules. I was up most of the night. I read in Dr. Clark's book the toxins are released when the stones begin moving and the ornithine capsuleshelp with that problem. For my next six cleanses, I have taken the capsules and havebeen able to sleep most of the night. So, I think you definately need to take them. I purchased mine at a local health food store. I am lucky because the owner is also a supporter of Dr. Clark and knows exactly what I am talking about when I discuss different cleanses!
I would think it would be ok to go ahead and do the liver cleanse whenever you are ready. THe Lemonade Diet will be a benefit to you in so many ways!