I'm on 300 x 3 times a day. Is this the ceiling effect, what I mean have doctors been known to go higher kinda like gabapentin. I was on 800 4 x a day. But I think 900 is the most they'll go.
What kind of effect are you trying to get?
As far as the most recent science, except with a possible tiny effect on a small section of the brain for the gaba b Receptor, pregabalin and gabapentin do not actually directly affect the GABA receptors.
They affect the alpha-2-sigma receptor, voltage gated sodium channels, and voltage gated calcium channels, which seems to result in upregulation of the production of GABA in the brain through possibly some effect on GABA Transaminase and other Gaba related enzymes.
One of the side effects of gabapentinoids is that they somehow act as serotonin reuptake inhibitors which can cause serotonin syndrome that otherwise would never have occurred. Gabapentin and tramadol have been shown to result in serotonin syndrome when taken together. Or when taken along with antidepressants.
The only consistent effect that I've seen from gabapentin is that above 1200 mg a day, while you still have a libido, your dick is basically numb and it becomes increasingly difficult to achieve orgasm the higher the dosage goes.
This is just an observation based on the dosage my doctor prescribed for seizure prevention.