I have been on 10mg per day of Amlodipine for just over 2 weeks and it has definitely dropped my BP significantly, The side effects have been quite bad, Tingling hands, No energy, loss of appetite, pounding feeling in the chest, headaches and vomiting, Looking on the internet it seems to be a common thing, The doctor did say it would take 6-8 for this tablet to take full effect, Luckily i can put most things on hold for now.
If you dont get on with the Amlodipine ask your doc to move you onto Lisinopril. Its a much more modern Hypertension medication. I'm on 10mg daily with it and had a couple of days of mild headaches when I first started on it, but been fine ever since.