hello, I have blood results today, I don't use steroids, peptides and other. Im natural. I have little muscle by nature, my strength is below average, I'm hardgainer. Fat up no problem, muscle up is a problem for me. So I think igf-1 is not so important for muscle growth because I would have to be big, strong and without fat with my igf-1 levels 306 Im 27yrs old.