My pysch also mentioned a body of water that some believe is helpful but he claims it does not contain any of the lithium that is needed, nor would enough be absorbed even if it did.
No injections are not available. Not saying it is not going to be available soon but even if it is I wouldn't try it. Lithium didn't work for me but for those whom it has it has always been pill form and it as been since it came out. Except for when it was first discovered and the story I heard was that there was a body of water somewhere in the world where people went and they noticed that there mood was improved when they went there. Have you tried other mood stabilizers? Lithium did not work for me.
My understanding is that injections are not available because it would be a lethal, or at least toxic, dose. I hope the lithium helps though. It's really helped me.
I've never heard of a lithium injection, and honestly, I would be kind of iffy as to whether or not they would have one. Lithium is a type of salt, which is why your psych will advise you to drink plenty of water and order blood tests every few months to test kidney functions.
A suggestion for remembering pills: cell phone alarm set to go off daily.