Is it safe to take 8 Adderall?

It would obviously depend of the dosage. Taking 6 5mg Adderall would be the same as taking 1 30mg Adderall. So, to just say "8 Adderall" can be anywhere from 40mg to 240mg. It also depends on tolerance. If you have little or no amphetamine tolerance, I would not exceed 20-30mg in 1 dose. If your amphetamine tolerance is through the roof, you could probably handle a very large amount. This is not "safe" though, being that large doses of amphetamines can cause long term cardiovascular and psychological damage.