What chemical can decrease reaction time so much that everything seems to be moving in slow motion?

I am compiling a mixture of chemicals in what I call the H.S.S (Hyper Soldier Serum). So far i have strength, speed, senses. My serum allows you to lift 3000 lbs. and then go take out a small army. The final ingredient is this one chemical. I would also like the lethal dosage please and some background. I am currently working on this with lab funding. Price is not important.