If i chose to take a otc fat burner which would be the best and how would it effect my bp?

Don't do it!: No such thing as "otc fat burner". It's all marketing hype w/o any studies demonstrating either benefit or safety. So which is best? None of them are any good aside from making manufacturer rich. As for blood pressure, more likely to raise your blood pressure. Stick w/lifestyle changes rather than short-term fixes. Look into mediterranean diet as well as how to exercise regularly.