Animak Pak - multivitamin

I started taking one Pack a day 2 days ago because I have heard good things about it if you are training. There are quite a few amino acids in it. Both times I take it I get a headache after 20 m that goes on for hours and am fatigued (as in sleepy) by it. I also get very mild cold/ flu symptoms. Have any of you tried the animal Pak and know what is going on? I haven't changed anything else, drink about 1-1.5 gallon Water a day and do sleep the 7-8 hours a night. I am thinking about returning this back to amazon even though I used 2 packs.

Here is a review of the Animal Pak:

http://voices.yahoo.com/review-universal-animal-pak-multivitamin-multimineral-3221931.html?cat=5

I am taking these to help with building muscle, being that is a goal of mine. These are not to be taken during weight loss phase of VSG post op.