Mmmm, not quite right. It very well should be white grape fruit juice, red grapefruit does not have nearly the same concentration of the enzyme inhibitors as white does. I reiterate, ...WHITE!!! is the way to go, lol.
This is from both research and lots of experimentation. White grapefruit is a very effective potentiator for most opiates, as well as benzodiazapines, ....that said, always be careful with the juice, that is why many scheduled meds have grapefruit warning labels on them. I used to get either red or white for awhile, up until I found out there was indeed a difference, and definitely not placebo, very very noticeable difference, ...and it has become a staple of mine in helping to stretch my little chemical helpers ever since.
Good luck and enjoy it, I personally hated grapefruit juice awhile ago, now I have become acclimated, and even really enjoy it.
Side Note: I have heard pretell, ..that "from concentrate" WGFJ contains more of the enzyme inhibitors than does 100% juice, ...and not sure if it is just speculation, both work very noticeably well for me, and the concentrate does seem to work a little better. Not sure how much, if any, of a difference there actually really is. Just thought I would throw in my 2 cents, hope this helps, .....cheers