I was told by my Primary Care Physician to take the sublingual form of B12 and the same day I took it I started to have more energy. The second day came along and I took it again and noticed I was feeling better again. I wasn't sure if it was from this B12. How can something help you this quickly, I thought. After 10 days taking it every morning I was definitely feeling better. I thoroughly enjoyed having more energy but it also decreased the headaches, dizzines and unsteadiness I had been experiencing for several months.