Yup, me too, when things were really bad.
And for many of the same reasons that why protein does. I also used gelatin (not collagen, which is pretty much first-pass gelatin) for its various properties, including joint and muscle pain (this was before I discovered this site and I had no idea what was going on with me, except that Drs didnt believe it and I started not to, too), better sleep (proline and valine), etc etc etc....
The thing is, collagen is much like whey in terms of its amino acid structure.
The hides and bones of, usually, cows or pigs, are boiled, then dried down, then treated with a strong acid, all of which would sever the aminos one from the other. Then the dried compound, which is collagen, is ground into a fine powder and sifted to produce gelatin.
So once again, you're dealing with a substance with the strong probability of a high free glutamic acid/glutamate content. I know that it eventually made me want to peel off my skin and run shrieking from the room.
I cut it out right after the whey protein, as part of my 'calming the CNS and brain' project. What I didnt know at the time was how much glutamate exists in everything we eat, whether we're vegans or vegetarians or carnivores, and how hard it is to give the system a break from all that for long enough to reverse the bad effects and be able to slowly reincorporate everything from foods to supplements to herbs.
Life. Ya' gotta love it.
