I have looked into this quite a bit. There are commonly accepted "compatible" peptides that clinics and people are putting together without any obvious bad effect. However there is no actual research done that tests this.
As a medical person I know that there are lots of medications which cannot ever be combined to inject via IV together. And they aren't obvious bad combinations like putting oil and water together, it's tricky. This is for meds coming from a controlled FDA oversight production chain. Throw in different fillers and an unsupervised production chain in the gray market, and the things that get combined in the vial may not agree causing degradation or other side effects like worsened injection site reactions.
I have to say that almost nobody in the peptide community will agree with my viewpoint but I stand by at least warning people that combining peptides may actually be causing harm, you don't know. Would I ever do it? Maybe. Depends on the peptides I guess 🤷♂️ For these two, I haven't seen anything about them being sold together in a mix at clinics.
