Blood pressure hasn't been a problem. After seeing the Doctor he has me increasing my dosage by one more capsule every 8 hours. I will do it over a 3 week period. I started on Thanksgiving taking 4 at bedtime, then one week later 4 at 6:00am when I get up and this Thursday I will take 4 at 2:00 pm. So far so good and I can feel more energy during the day and no side effects.