I took my first 500 mg of Vitamin C today. I'll take one every day. I am betting it will be at least a month before there is any evidence of anything. I will continue to take my Lisinopril for the duration.
The research this is based on is located on the original blood pressure post
My current average morning BP is 112/75.
EDIT: I have also been taking a multivitamin for quite some time with 90 mg of Vitamin C. So 590 mg of Vitamin C a day.