Peptides are not a single category with a single status. Some are FDA-approved drugs with a defined label. Others are investigational compounds studied for narrow uses. A few circulate mostly as imports with little formal oversight. When you are comparing legal, prescription-based providers, that spread matters more than any marketing claim, because it decides whether a compound can reach you through a licensed pharmacy at all.
Here we walk through the five peptides in that framing. We are not judging whether any of them work. We are describing what each one is on paper, and what that means for access and price.
The FDA-approved GLP-1 drugs
Semaglutide and tirzepatide are the clearest cases. Both are approved by the FDA and sold as branded products with published labeling. A prescriber writes for them, a pharmacy dispenses them, and the supply chain is traceable. That is the most conventional path a peptide-adjacent drug can take.
Compounded versions have also been available at times, but that availability tracks FDA shortage determinations and can change. When a branded drug is no longer listed as in shortage, the basis for routine compounding narrows. If a provider offers a compounded GLP-1, it is fair to ask which pharmacy prepares it, whether that pharmacy is a 503A or 503B facility, and how the current shortage status affects what they can legally make.
An approved drug with a specific indication
Tesamorelin is FDA-approved for a defined indication, which means it too has a label and an approved manufacturer. Approval for one use does not make every use on-label, and prescribing outside the labeled indication is a clinical decision between you and a licensed clinician. The practical point for shoppers is that an approved product exists, so you can ask a provider to explain exactly what they are dispensing and from where.
Investigational and loosely regulated peptides
Thymosin alpha-1 and semax sit differently. These are investigational in the United States and are not FDA-approved drugs. Thymosin alpha-1 is approved or marketed in some other countries, which is not the same as US approval. Semax has a history of use abroad and appears widely as a research chemical online. Neither status gives you the assurances that come with an approved product and a licensed dispensing pharmacy.
What drives cost
Price differences usually reflect a few concrete things: whether the compound is a branded FDA-approved drug or a compounded preparation, the type of pharmacy involved, the strength and quantity dispensed, and whether a telehealth visit and follow-up are bundled in. Insurance may apply to approved drugs for approved uses and rarely applies to compounded or investigational products. A quoted monthly figure is not comparable across providers unless you know what it includes.
How to vet a provider
The vetting questions are the same regardless of which peptide you are looking at. Ask for specifics and expect clear answers.
- Is there a licensed clinician who evaluates you and writes the prescription, with real follow-up?
- Which licensed pharmacy fills it, and is it a 503A or 503B facility you can verify?
- Is the product FDA-approved, compounded, or investigational, and does the provider state that plainly?
- What does the price include, and what happens if a compound's legal availability changes?
A legitimate provider will not blur these lines or promise outcomes. If someone dodges the question of what they dispense and where it comes from, treat that as the answer.
The takeaway
Evidence and legal status are two separate axes, and a peptide can rank differently on each. Approved drugs like semaglutide, tirzepatide, and tesamorelin have a defined regulatory footing. Investigational compounds like thymosin alpha-1 and semax do not, at least not in the United States. Knowing where a compound sits tells you whether a licensed pharmacy can legitimately supply it, which is the question that actually protects you.
This is general information, not medical advice. Decisions about any of these compounds belong with a licensed clinician who knows your history.