Know who actually compounds your medication
The first question with anything you put in your body is provenance: who made it, in what kind of facility, and what is actually inside. With a lot of cheap online peptides, that answer is a shrug. A label that says "research use only" or "not for human consumption" is not a quirky disclaimer. It is the seller telling you, in writing, that the product was never intended for a person and was never handled as if it would be.
What good looks like is a clear, named source. Compounded medications should be made by a licensed US pharmacy that is registered with its state board, follows pharmacy compounding standards, and prepares your prescription against a valid order from a provider. It is fair to ask, before you start, which pharmacy fills the prescription and whether sourcing and testing information is available to you. A program that can answer that question clearly is treating you differently than one that cannot.