Long time ago HGH was made by isolating it from pituitary gland tissue taken from human cadavers which many times resulted in different diseases in users.

Later appeared the idea of recombinant DNA which means HGH was made synthetic and made HGH safer to use which did not have those sides users were getting from non-synthetic HGH.

So they added an "r" before HGH to be known that that HGH is synthetic.

Now as far as we know all HGH is made using rDNA technology so nobody puts an "r" before.

I dont know if they even make now non-synthetic HGH.

To read more about rDNA method click here: https://www.onlinebiologynotes.com/p...na-technology/