B12 oils.com I'm using DIY, you can read about it in the thread Transdermal B12. There's also another recent thread re transdermal B12, you might find it, where I again related my experience. I'm using Bluebonnet MB12 5000mcg drops, mixing in my palm w/ some body creme, and applying. working great.
Since I had a bunch of regular B12 pills sitting around, I decided to crush them up and mix them with ascorbic acid and follow the recipe using an ultra sonic cleaner machine.. from what I can tell, B12 crushed pills powder worked quite well.. and I don't have my dizzy spells symptoms in last 4 days which is an amazing improvement..
used the recipe here - PS: for my experiment, I did NOT buy the expensive B-complex powder the creator of the youtube video is selling .. I just crushed whatever cheapest B12 pills (with 4+* rating) I could find on amazon..