I dont remember the exact amount of time it took to adjust to propranolol but I do remember my doc feeling confident it would help me and he told me to not give up on it, take every dose on time, and give it at least 2-3 months. It made my symptoms as far as low bp, dizziness, and near syncope much worse at first and I could barely get up for anything. But, I did adjust to it I believe around 6-8 weeks after starting and it has been the best med for me. I'm glad I stuck with it. It of course doesn't help all symptoms but helps the cardiac stuff. No more bp drops, controls heart rates, no more chest pains, helps with the chronic headaches, even the shakiness and nervousness associated with tachycardia are relieved by it. I take 40mg 3xday. I have been on it for a couple years now and it still works just as well for me. I hope you and your doc find one that works for you too!