What Is Peptide Therapy? Approved Drugs, Compounded Peptides and Research Vials

Peptide therapy is a clinic’s name for prescribing short chains of amino acids, usually as injections. It covers three very different things. Some are FDA-approved drugs with large trials behind them, the GLP-1 weight-loss medicines most of all. Some are compounded by a pharmacy from raw ingredients that FDA has never approved. And some are “research-use-only” vials sold online with no prescription. Since October 28, 2026, HHS has said it does not intend to take enforcement action against 503A pharmacies that compound six popular peptides under strict conditions, but that made none of them an approved drug.^[2]

What a peptide is, and what clinics mean by the term

Peptides are short strings of amino acids, which are also what proteins are built from. US drug regulation draws the line at 40: a chain longer than that counts as a protein.^[1] Many hormones the body makes are peptides, and so are several modern drugs.

“Peptide therapy” is a menu heading, with no FDA category or medical specialty behind it. Of the 636 sellers in our register, 174 list at least one peptide product. The most common item is NAD+ (154 sellers), followed by sermorelin (123) and glutathione (81). NAD+ is a coenzyme built from two nucleotides, so it is not a peptide at all, even though it is sold beside them.^[12] Three of the menus in our register list retatrutide, a GLP-1-family drug still in trials. Its maker says it has not been reviewed or approved by FDA or any other regulator and that no one can legally sell it for human use.^[21] Our retatrutide article covers where it stands.

The useful question about any item on the menu is which of three kinds of product it is. That decides whether anyone checked that it works, whether anyone checked what is in the vial, and whether the sale is legal.

FDA-approved peptide drugs

The peptides with strong human evidence are the ones that became approved drugs, each for a specific condition. The best known are the GLP-1 medicines. Wegovy’s label describes semaglutide as a GLP-1 receptor agonist whose “peptide backbone is produced by yeast fermentation.”^[4] Zepbound’s tirzepatide is built on the sequence of a second gut hormone, GIP, and acts on both receptors.^[5] Both are approved for losing weight and keeping it off in adults who have obesity, or overweight together with a weight-related condition.^[4][5] Our explainer on whether GLP-1 drugs are peptides goes into how they are made.

Two other approved peptides show up on clinic menus. Tesamorelin (Egrifta WR) is approved to reduce excess belly fat in adults with HIV-associated lipodystrophy.^[8] Bremelanotide (Vyleesi), a cyclic peptide of seven amino acids, is approved for one form of low sexual desire in premenopausal women, and its label says it is not meant to enhance sexual performance.^[9] Sermorelin was approved as Geref and studied mainly in children with growth hormone deficiency.^[10][11] It was later discontinued, and FDA recorded that the withdrawal was not for safety or effectiveness reasons.^[10] What clinics sell today is compounded sermorelin; our sermorelin article covers what that means.

An approval covers the condition that was tested. A clinic that prescribes tesamorelin for general fat loss, or bremelanotide as a libido booster for anyone, is prescribing off-label, and the trials behind the approval say little about that use. The full list is in FDA-approved peptides.

Compounded peptides

Compounding is a pharmacy making a medicine for one patient from raw ingredients. HHS’s own policy states the limit: “Compounded drugs are not FDA-approved, which means FDA does not review their safety, effectiveness, or quality before they are marketed.”^[2] A compounded peptide can still be a legitimate prescription, made in a licensed pharmacy from a tested ingredient. What it lacks is any FDA finding that it works.

Small 503A pharmacies fill prescriptions for individual patients. Larger 503B outsourcing facilities make batches. The difference matters for peptides, because the new HHS policy covers only the first kind.^[2][3] 503A vs 503B pharmacies explains the two.

Research-use-only peptides

Much of the peptide trade runs through websites that sell vials labeled for research and not for human use. No one prescribes, no pharmacy is named, and the label is there to keep the seller out of drug law. HHS gave this market as its reason for acting in October 2026: it wants to “discourage the continued, widespread use of certain research-use-only peptides supplied by foreign manufacturers that pose a safety risk to US patients.”^[2] The policy does not cover these sellers. Research-use-only vs compounded peptides sets the two side by side, and FDA’s warning letters to peptide sellers show what the agency objects to.

What changed on October 28, 2026

HHS said it does not intend to take enforcement action against state-licensed 503A pharmacies, federal facilities or licensed physicians that compound BPC-157, TB-500, epitalon, Semax, KPV or MOTS-c, as long as ten conditions are met.^[2] The ones a patient will notice:

• A prescription written for you. The policy keeps federal law’s patient-specific prescription requirement.^[2]
• One peptide per product. Blends and stacks fall outside it; see peptide blends and stacks.^[2]
• Set routes for each peptide. Semax only by the nasal route, KPV only by mouth or on the skin, TB-500, epitalon and MOTS-c only by injection. BPC-157 may be injected, swallowed or applied to the skin. A separate condition names an FDA-cleared syringe as the only device that may come with the product, and the policy does not say how that applies to a nasal product.^[2]
• A tested ingredient. The raw peptide must come from an FDA-registered facility with a certificate of analysis covering identity, purity, potency and contaminants such as endotoxins, heavy metals and microbes.^[2]
• A label you can read. It must say “This is a compounded drug product. Not for resale.” and explain how to report a side effect or quality problem.^[2]

It is interim, lasting until a final rule decides whether each peptide goes on the 503A bulks list, HHS may revisit it sooner, and it does not reach 503B facilities or research-use-only sellers.^[2][3] The HHS peptide policy explained walks through all ten conditions and how the six got there.

What the evidence looks like for the popular ones

For the wellness peptides, most of what is known comes from cells and animals. When FDA reviewed the six peptides in the HHS policy for its July 2026 advisory committee, its briefing documents found little or no human data for most of them.^{[14][15][16][17][18]} HHS chose to allow compounding anyway, saying it wanted to “expand and improve patient access while FDA reviews these substances.”^[2]

The peptide menu lines up the whole list against its count of human trials. A low count is no proof of harm. It means the benefit and the risks in people have not been measured.

Peptide therapy for weight loss

The peptides with real weight-loss evidence are the GLP-1 drugs. In the STEP 1 trial of 1,961 adults, weekly semaglutide 2.4 mg cut body weight by 14.9% over 68 weeks, against 2.4% on placebo.^[6] In SURMOUNT-1, 2,539 adults on tirzepatide lost 15.0% to 20.9% of their weight over 72 weeks depending on dose, against 3.1% on placebo.^[7] No other peptide on a clinic menu comes close to that record; peptides for weight loss ranks each one by its human evidence.

The others sold for weight loss have no such trials. Tesamorelin’s own label says it “is not indicated for weight loss management as it has a weight neutral effect.”^[8] MOTS-c’s weight claims rest on mice.^[16] Sermorelin was approved and studied for children with growth hormone deficiency, not for weight loss.^[11] If weight is the goal, a clinic offering peptide therapy should be talking about a GLP-1 medicine first. If you already take one and are considering adding another peptide, read peptides alongside a GLP-1 before you do.

What peptide therapy costs

Prices vary by peptide, by form and by clinic, and many clinics quote only after a consultation. Only 25 of the 174 sellers with a peptide menu in our register publish a peptide price we can record. Where prices are published, our rankings show them: sermorelin providers, the cheapest sermorelin, NAD+ providers and the cheapest NAD+. For GLP-1 medicines, which are priced and sold very differently, start with the cheapest semaglutide.

How to judge a peptide clinic, local or online

Searching for peptide therapy near you turns up med spas, longevity clinics and telehealth sellers. The same checks apply to all of them.

1. Who prescribes? A licensed prescriber should review your history and write a prescription in your name. A checkout page with no clinical review is a research-chemical sale.
2. Which pharmacy? Ask for the pharmacy’s name and whether it is a 503A pharmacy. You can confirm its license with your state board of pharmacy. Under the HHS policy, only 503A compounding of the six peptides is covered.^[2]
3. Is the product a single peptide? A blend of BPC-157 and TB-500 in one vial falls outside the policy.^[2]
4. Can they show a certificate of analysis? The policy requires one for the raw ingredient. How to read a peptide certificate of analysis explains what the tests mean.^[2]
5. Does the label tell you how to report a problem? Under the policy it should, and the pharmacy must report serious adverse events and quality problems to FDA’s MedWatch program.^[2][20] You can report to MedWatch yourself.
6. Is the peptide sold for an approved use? If the clinic’s claims go well past what the approved label or the evidence page supports, treat that as a warning.

Our peptide guides profile each peptide sellers offer, with the sellers that list it.

Common questions