Does gabapentin cause headaches if the dose is too high?

Hi, Anon!
Headaches can be a side effect with gabapentin either when first starting the medication or sometimes after a dosage increase especially if the dosage increase is significant. They usually resolve within a few days to several weeks... but everybody's response to the medication is different.
What dosage were you taking and what was it increased to? It may be that the original dose was low enough not to cause the headaches.
At any rate be sure to report the headaches to your doctor. You'll also want to rule out any other underlying cause.
Best regards and I hope you're feeling better quickly.

I was on 3600mg a day for quite awhile. Didn’t have any problems.