No, unlike GHB, GBL is hepatoxic so toxic to your liver because your liver turns the GBL into GHB. It can be pretty damaging to you physically but the withdrawals are what id be more worried about. You do realize GABA drug WDS(Alcohol, benzos, GHB/GBL/1,4b) can kill you pretty easily if your habit gets bad enough and your unable to find anything to stop the WD's, apparently you can just seizure out of nowhere and die without even feeling that bad before the seizure. Not to mention anxiety & depression & all the rest.
I cant quite think what else is so bad about GBL compared to GHB but there are other reasons why its physically damaging. Now 1,4b, that stuff is baaaad for you and I wouldn't recommend even bothering with the stuff. I prefer GBL to GHB myself due to the faster come up, I think its more euphoric, you need less and its just awesome but GHB is basically completely safe in regards to toxicity, it gets eliminated by the liver very efficiently and basically does no damage to your body unless your dependent and having seizures/DT's/WD's.
If your friend cant control their G use id strongly suggest staying away from it, benzos and alcohol. They are 3 drugs than can land you in a world of unimaginable hurt & ive been addicted to many drugs but never any of those because GABA drug withdrawals scare the absolute crap out of me!