Poop. I am interested in this subject too (OTC "replacement" for insulin)
Berberine seems interesting. This Physician seems to suggests and cites a study done that it preferentially makes "muscle cells" more sensitive. http://www.faim.org/...-diabetics.html
Who kmows and that said, I looked into all these GDA's and insulin mimickers years ago and NOT ONE of them seemed to make the glut4 receptors in muscle cells (vs fat cells) more sensitive.
Then again, insulin itself does not prefer muscle cells over fat cells. Lol.
In my limited knowledge of this subject, I'm pretty sure exercising the muscle and then eating a mono or disaccharide (non-fructose based) would be the best way to get the sugars into the muscle as I don't recall anything that magically makes the muscle-specific response better/preferred.
I'd imagine if one would desire to quell the insulin response associated with carbohydrate ingestion; (so as to not experience the sides: lethargy, inflammatory response intrinsic to insulin) then perhaps the use of a GDA or better than that, an insulin mimicker, this could assist even more (speculation here) with overall nutrient absoprtion into the muscle cells post-training (but then again, is this even needed?)
In for a learning .....
Hey DrCoop: what about the old-school non-exotic choices like vanadium, acetic acid (vinegar), gymnema, r-ala, chromium polynicotinate? Sure, they're not SEXY as the new generation GDA's but are time-tested and sometimes, old school trumps new BS.
Look at the safety profile of Metformin vs Avandia for example!