i searched the net, but cant find anything. What’s the difference?
Glutamine containts nothing but the amino acid glutamine.
Glutamine AKG contains both glutamine (probably in the positively charged form, which makes no difference) and alpha-ketoglutarate (the negatively charged form of alpha-ketoglutaric acid, assuming they are using the negatively charged form of glutamine. If not, then they will be using alpha-ketoglutaric acid itself.)
So the results are:
The amount of glutamine is now only a percentage of the weight of the product you are buying, rather than all of it. About 50% as the molecular weights are almost identical.
You are also getting AKG, which also offers some benefit to it.
Now, as to whether what happens is that the glutamine and AKG, like sodium and chloride in table salt as an analogy, separate from each other in water solution and there is therefore no difference between taking the two products separately; or whether they remain associated but to no practical consequence in the body; or whether they remain associated with a resulting improvement in some way, e.g. more glutamine reaching the bloodstream, I don’t think is predictable from principle but would require experiment.