Maybe HGH works for lab rats nerve regeneration. I had a surgery that didn't cut nerves but caused nerve stress and it stopped working for a while. Even with HGH it took several years for the nerves to come back. I have been on HGH continuous for over 6 years and my nerves in my knee, where I had the surgery, still is not coming back. Who knows? Maybe it depends on where the nerves are severed.