#1

As I am planning peptide use.

Review article;

https://www.sciencedirect.com/science/article/abs/pii/S177322472031296X

#2

Depends on the peptide. I doubt anyone is going to invest in creating a transdermal version of BPC-157 but they might for GLP1-R’s

The “research chemical” market would not be ready to get into this without good reason and improved ROI.

#3

I was hesitant to use subcutaneous injections at first, but remember, millions of diabetics do this every day.
Supplies are cheap. I use 1 ml and 0.5 ml insulin syringes from Amazon.
I find it painless. Just be sure to use the proper techniques covered in many YouTube videos.