Thanks for your query.
is a fat burner and contains many ingredients some herbal and some chemical.
It also contains caffeine in higher amount that any other product.
, excitement, insomnia, flushing of the face, increased urination, gastrointestinal disturbance are some side effects of oxyelite pro.
Similarly I guess from your history it seems you are getting hyperacidity
after taking this product which may be causing pain in stomach and esophagus resulting in feeling of chest pain.
I would suggest you to stop it immediately and get treated for it.