I've been taking 10mg. Altace daily since March of this year when BP was 204/110. It took about 10 days to two weeks for it to really "kick in", but once it did it worked like a charm for me. My BP now runs 120's/70's, and I have no side effects at all, not even the irritating cough. Best of all I can go out in the summer heat without feeling so weak and light-headed that I'm afraid I'm going to pass out! That was the main problem I had last year when I was taking Labetalol and Lotensin. And when you live in the Deep South that is indeed a problem!