For our experience , they get 99% purity is a good lucky or even an accident al ,because of the difference between the detection method and personnel, this purity error is still 1-3 point, in general ,94+% purity can be medicinally injected.
Because gh is fermentation protein,the purity will not be as high as other polypeptides can reach 99.9% or 99.5%,so 96% is generally good to use.
Don't need to blindly pursue the ultra-high purity of protein, in case of meeting the medical requirements, the content can be sufficient .