would it be safe to increase the bioavailability of thermogenics of otc thermos such as guarana and even more dangerous ones such as ephedrine with grapefruit juice? even if it were to work, would it make the thermo effect stronger?

one more question. ive done an ECA stack before and finished the cycle when my tolerance for ephedrine went up so would grapefruit juice make the cycle more worth while and less dangerous if the dosage stays the same but adding graefruit to it in order to produce the same effect when the cycle was first started?