Hi everyone, I am 20 years old and have very low blood pressure as 90/80. I feel very weak and lightheaded when I stand for long time. I am not interested of drinking coffee since it is too acidic for my stomach but was wondering if I choose to take coffee pills? Are these helpful or harmful and how many should I take if I choose to take them to bring up my blood pressure?

I'd talk to your doctor about your blood pressure if it's a concern for you...

What purpose would caffeine pills serve you -why do you want to take them?

Why don't you try to sleep for a long time?

If you want to loose some weight with pills it's better to drink natural pills like tea pills. (Look at my signature, this is a great solution!)

It seems you suffer from hypotension(chronic low blood pressure). I would advise you seek medical advise on your current situation from a physician.
Than start researching it so you can learn to manage and help control it as much as possible.