The Massachusetts Medical Society states, "Naturopathic practices are unchanged by research and remain a large assortment of erroneous and potentially dangerous claims mixed with a sprinkling of non-controversial dietary and lifestyle advice."
If silexan isn't effective, surely you can prove that empirically and without resort to an argument from authority. If a naturopath says drinking water is good for you too, that doesn't mean that specific claim is wrong because naturopathy is pseudoscience (which it is). We're evaluating silexan here.
Larger discussion is that a lot of modern medicine is not based on well-replicated studies, either
1) he wasn't into the woo-woo stuff - he'd present papers on efficacy. So if I were talking to him about a specific issue he'd quickly look things up on his laptop "I was just reading a paper on this the other day, here let's take a look..."
2) he'd actually take time to listen - appointments were at least 45 minutes. Sometimes 1 hour. All the MD's I've been to since seem to be in a huge rush - you're lucky to be in there for 10 minutes (not the fault of the MDs, likely, more the fault of our healthcare system)
3) he taught complementary medicine to MD students at a local Medical School so he wasn't anti-MD as some NDs are. He was well aware of the limits of naturopathy and didn't hesitate to send me to a specialist when needed.
4) Very comprehensive blood tests. I haven't had an MD who tested for so much. And just because some parameter was in the normal range he didn't necessarily consider that everything was ok. He'd say stuff like "this is considered the normal range [for this parameter] but it's right on the edge of normal, we need to look into this further... (or we need to keep a watch on this)"
5) he thought like an engineer - most doctors aren't great at troubleshooting, in my experience. This guy was a good troubleshooter. He got me through some digestive issues that I'd been dealing with for a long time because nobody else seemed to dig into it like he did.
Unfortunately he retired a few years back - because of his reputation he was in huge demand and I think he just kind of burned out. In the years since I haven't found a replacement doctor that I've been happy with (either MD or ND).
A friend of mine had issues with irregular menstruation: months with nothing, and doctors weren't able to help. The same naturopath identified a deficiency by ways of a blood lab, and those problems have also been solved.
Naturopaths are a worthwhile starting point, the one I visited could even prescribe if all else failed, but I'd walk out if one didn't start with a blood lab/science.
Of GABA? What form? I've heard that it's not well absorbed or gets destroyed in digestion, but then others say it's best absorbed orally by sucking on a lozenge.