Confused about IGF Aplication

I just recieved some IGF.I am suposed to inject it right?Directions confused me and just want to make sure.It's my first time using IGF and I know your usually supposed to inject.I'm sure this is a stupid question.

each notch on a 1ml U-100 slin stick equals 10mcg......so when you get to the 10 it's 100mcg, 20-200mcg, 100-1000mcg. Apply it as you wish.

Thanks.I knew how to measure mcgs it was how to apply it confused me on the directions.I didnt want to apply myself with something that I was supposed to use transdermal which I had never heard of applying it that way.I got it though.Thanks for the response