Newbie question

Hello!

I am in the midst of trying to get started on mounjaro. My doctor wants me to start but we are trying to get the work around for me to get on it, like getting a script from having bad sleep apnea
In the meantime, my mom and grandma are on mounjaro and have extra since they went up on their medication. I want to start but the meds are too strong (7.5mg) and I want to know if I could just take a lower dose through the pen and buy extra needles for the pen?

Any help would be amazing!