It is hard to know how to answer this question since peptides aren’t “one thing”, right?
It is a large group of signaling  agents which include everything from insulin, to TA1 (and a lot in between). These all have very different functions, actions, and indications, etc.
As such, labs for one indication (insulin for DM e.g.) would be very different from another one (TA1 for Lupus for example).
My advice is, if you are new to this amazing group of treatment options… that you pick one peptide at a time to get to know.
Read about indications, dosing, side effects, contraindications, expected results, and labs to be followed.
Then try it out, and learn from using it.
And then, pick another one… and do the same.
For me, the above plan was the best way to successfully (and safely) start using peptides.
And, as you do the above… it will be much easier for those of us who have already “played with” the peptide you are working on to answer questions that you might have, or help you avoid the pit falls that we might have learned from.
Warmly,
Cynthia