Products like Creatine Serum are a waste of time. It's IMPOSSIBLE to make a stable non-degrading product with creatine in solution. Well maybe if you wrapped it in something else - aka encapsulation. But at a stupid cost vs the pills and powder.
Didn't even know they make it in liquid form these days.
But I would not bother buying it before seeing some research of it first. Probably not any better than the regular monohydrate.