my B12 was on the low normal side and I was having all these sypmtoms. The sub-linguals work really well. They stopped working for me after about 5 years and I had to go with the shots. I still developed TN, about a year and half ago, possibly much earlier so the idea that it might be the actual cause of TN is still under debate. But it can't hurt. If any damage was done on the myelin sheath it's most likely permanent. But at least the B-12 is important for the health of the myelin sheath. And after about a month on B12 my symptoms of pernicious anemia stopped. If they could repair the myelin sheath they would be able to cure ALS and other demylinating diseases, but that hasn't happened yet. But B12 can't hurt, you can take a ton of it and it won't do any damage. And you have to take a very high dosage just to get the few micrograms you need. So make sure you get a high dose B-12 or take more of them. I do believe the shots are 1000mcg and you only need 1-2 mcg but at the end of the month I really need another shot. The problem with a mixed supplement is that the amount of b12 won't really do anything. High dosage pure b12 sublingual is the way to go. You can still take your supplement but just add this to it. Many vitamins can be dangerous at high dosages but NOT b12. It won't do any damage at any dose, my neurologist assured me of this.