Jack3d, 3 Scoops, Tight Chest. Drink Lots Of Water?
Thanks for the query.
It is because of the 1,3 dimeth and its stimulant effect. Could be that you have taken more caffeine in today than normal, or not had enough water. Ideally people take 2 to 3 scoops and you have taken 4.5 scoops.
Caffeine is a vasoconstrictor, which shrinks your blood vessels and causes the heart to work harder, hence the tightness in your chest. Most of the time, this should not be an issue, but if you are in pain or have a history of heart issues, discontinue use and consult a doctor.
One thing I would like to keep in is mind though with these is that it is always a good idea to give your body a break from taking supplements once every 2-3 months for 2 weeks.
Hope my answer is adequate, I am available for follow up should you have any more concern.