Re: Lantus causing headaches?
It's possible. There are so many things we do not know about synthetic insulin, especially lantus. Lantus is a liquid when injected, but precipitates in the muscles immediately. As the pH changes over time in the muscles, the lantus resuspends, absorbs, and is distributed throughout the day. Because there is an initial equilibrium "boundary" reached (around 3 hours), there will be a slight "peak" in activity at or near this time. The point is that the soldified substance in the muscles is likely foreign to the body, and your guess is as good as mine as to how the body responds. When the liver processes the lantus, there has to be some degree of methylation as well, and I suppose down the road "metabolites" of these compounds could cause headache. Again, just speculative.
As a side note, I like lantus and I think it does a good job. But because of the varying pH's in the muscles at various times of the day, you will notice "dead times" and sort of "peak times", but not nearly as drastic as NPH or Regular insulins. If I were you, I would recommend really researching this topic and seeing if others notice similar side effects.