FDA-approved peptide drugs: a complete inventory across therapeutic categories

The class is defined by chemistry, not size. A peptide is a chain of amino acids linked by amide bonds; by FDA convention, anything 40 amino acids or shorter is regulated as a peptide drug under a New Drug Application, while longer chains generally move into the biologics column under a Biologics License Application. The cutoff is administrative rather than biological, and it has consequences. Insulin, originally licensed as a biologic, was transitioned to NDA status in 2020 under the BPCIA reforms; semaglutide and tirzepatide entered as peptide NDAs from the start. The distinction shapes which abbreviated pathway a generic or biosimilar can use, which is a more concrete fight than it sounds.

The class is large and not new. Insulin was approved in 1923. Oxytocin followed in the 1950s. As of mid-2026 there are roughly 130 approved peptide entities across the catalogue, and peptides have accounted for about 10% of new FDA drug approvals annually for the past several years ^[1], ^[2]. The chemistry has matured around a small set of modifications that solve the field's defining problem - peptides get chewed up fast in plasma and gut. Lipidation (the fatty-acid chain on semaglutide that lets it bind albumin and ride around for a week), PEGylation, cyclization, D-amino acid substitution, and non-natural residues are the workhorses ^[3]. None of this is exotic anymore. It's why a weekly injection can replace a four-times-daily one.

Approval runs through either an NDA (for synthetic peptides ≤40 amino acids) or a BLA (for larger or recombinant products). The clinical evidentiary bar is the same as for small molecules: adequate and well-controlled trials demonstrating large evidence of efficacy and an acceptable safety profile in the proposed population. Where peptides differ from small molecules is in manufacturing scrutiny. CMC review for a peptide NDA hinges on sequence verification, impurity profiling (D-isomer content, deletion sequences, truncation products), and the immunogenicity assessment - because even a small structural drift can trigger neutralizing antibodies that abolish efficacy or, worse, cross-react with an endogenous hormone. The agency's 2023 enforcement actions on compounded peptides leaned heavily on exactly these concerns.

A peptide approval is also an indication-specific thing. Tesamorelin is approved for HIV-associated lipodystrophy; it has never been approved for healthy adults seeking visceral fat reduction. Bremelanotide is approved for hypoactive sexual desire disorder in premenopausal women; it's not approved as a general libido enhancer for men. The compounding world routinely sells these molecules - or close analogs - for indications that have no approval and no controlled-trial support. That's not a footnote. That's the entire story of how the legal categories diverge from the consumer-market categories.

This is the category that reshaped the conversation. Five GLP-1 receptor agonists carry current FDA approvals, plus one dual GLP-1/GIP agonist. Exenatide (Byetta) arrived first, approved in 2005 for type 2 diabetes - a twice-daily injection derived from the Gila monster's exendin-4. Liraglutide followed in 2010 (Victoza for diabetes, then Saxenda for obesity in 2014), pushing dosing to once-daily through a fatty-acid linker that bound albumin. Dulaglutide (Trulicity) extended dosing to weekly in 2014 through fusion to an Fc fragment. Semaglutide was approved as Ozempic in 2017 for type 2 diabetes, then as Wegovy in 2021 for chronic weight management, and as Rybelsus - an oral tablet formulation using the absorption enhancer SNAC - in 2019. Tirzepatide, the dual GLP-1/GIP agonist, was approved as Mounjaro in 2022 and Zepbound in 2023.

What the SUSTAIN program established for semaglutide and what SURMOUNT-1 established for tirzepatide (mean body weight reduction of 22.5% at the 15 mg dose over 72 weeks in the key trial, NCT04184622 ^[4]) is that the GLP-1 class has decisively crossed from a diabetes adjunct into a primary obesity therapy. That has consequences for the safety conversation. Nausea, vomiting, and constipation are the dose-limiting events for most patients; the titration schedules exist because the GI tract needs months to adapt to delayed gastric emptying. The class carries a boxed warning for medullary thyroid carcinoma based on rodent C-cell tumor signals that have not been reproduced in humans, but the warning persists because the rodent finding was clean. The diabetic retinopathy signal flagged in the SUSTAIN-6 cardiovascular outcomes trial has held up in subsequent meta-analysis (Kapoor and colleagues, 2023, 93 trials, relative risk 1.31 for early-stage retinopathy versus placebo, 95% CI 1.01-1.68) ^[5] - a finding most likely driven by rapid glucose lowering rather than a direct drug effect on retinal vasculature, but real enough that ophthalmologic follow-up is warranted in patients with preexisting retinopathy.

The compounding story for this class collapsed in 2025. After tirzepatide came off the shortage list in late 2024 and semaglutide followed in February 2025, the enforcement-discretion windows closed for 503A pharmacies in February 2025 and for 503B outsourcing facilities in March 2025. The April 30, 2026 proposal to exclude semaglutide, tirzepatide, and liraglutide from the 503B bulks list - with public comment running through June 29, 2026 - would close the last broad pathway for bulk compounding of these molecules ^[6]. What remains is narrow patient-specific compounding under 503A for documented clinical need (allergy to an excipient, requirement for a non-commercial dose), and that's a legitimately small population.

Tesamorelin (Egrifta) is the only FDA-approved growth hormone-releasing hormone analog, approved in 2010 for one indication: reduction of excess abdominal fat in HIV-infected patients with lipodystrophy ^[7]. The drug is a synthetic 44-amino-acid GHRH analog stabilized at the N-terminus to resist DPP-4 cleavage. It binds pituitary GHRH receptors and drives pulsatile endogenous GH release, which raises IGF-1 modestly and, over six months, reduces visceral adipose tissue by roughly 15-18% in the approved population. Dose is 2 mg subcutaneously daily.

Two things about tesamorelin are routinely misstated. First, the indication is HIV-associated lipodystrophy. The trial population that established efficacy and safety was specifically patients on antiretroviral therapy with the characteristic central adiposity that developed in the protease-inhibitor era. Extending the data to otherwise healthy adults seeking visceral fat reduction is an off-label extrapolation, and the safety database for that extension doesn't exist. The known adverse effects in the approved population include arthralgia, edema, carpal tunnel syndrome, and glucose intolerance - not severe, but not nothing, and meaningful when stacked over years in a non-indicated population.

Second, "GHRH analog" in the compounding marketplace overwhelmingly doesn't mean tesamorelin. It means CJC-1295 (a 30-amino-acid GHRH analog, with or without DAC, the drug-affinity complex that extends its half-life to days) and sermorelin (a 29-amino-acid truncated GHRH fragment that was approved as Geref in 1990 but withdrawn in 2008 and is no longer an FDA-approved drug). Neither CJC-1295 nor sermorelin has a current NDA. Neither has the trial evidence behind tesamorelin. The two are commonly stacked with ipamorelin, a pentapeptide ghrelin mimetic that was developed by Novo Nordisk in the 1990s, never completed development, and has no approval anywhere.

Bremelanotide (Vyleesi) was approved in June 2019 for hypoactive sexual desire disorder in premenopausal women - the first and still the only FDA-approved melanocortin receptor agonist for a sexual-function indication. Mechanism is nonselective agonism at the MC1R and MC4R receptors, with the MC4R effect driving the central pro-sexual response. The 1.75 mg subcutaneous dose is self-administered as needed, at least 45 minutes before anticipated activity, with a hard limit of one dose per 24 hours.

The clinical evidence is honest. Two Phase 3 trials (RECONNECT) showed a statistically real improvement in desire and a reduction in distress versus placebo, but the absolute effect sizes were modest and the placebo response was large - which is the pattern across the entire HSDD trial literature. Nausea is the dominant adverse event, reported by roughly 40% of patients and severe enough that 13% discontinued; flushing, headache, and transient blood pressure elevations follow. The blood pressure signal led FDA to contraindicate the drug in uncontrolled hypertension and cardiovascular disease.

The relevance to the compounding conversation is the molecule sold as PT-141. Bremelanotide is PT-141 - the development code carried through Palatin Technologies' program - but the FDA-approved product is a specific formulation, dose, and indication. The compounded "PT-141" marketed to men for erectile function, to both sexes as a general libido enhancer, and frequently combined with the older melanotan II for tanning effects, is not the approved drug used in an off-label way. It's, in most cases, a separately sourced bulk substance with no patient-specific clinical justification, sold for an indication FDA has never reviewed. Melanotan II - also commonly sold by the same vendors, also lacking any approval anywhere - is on the FDA's list of peptides under PCAC review, with the agency signaling skepticism.

This is the oldest and largest peptide-drug category in oncology and reproductive endocrinology. Leuprolide (Lupron Depot), a synthetic GnRH agonist, was approved in 1985 for advanced prostate cancer and remains the most widely prescribed peptide in U.S. oncology ^[8]. The pharmacology is counterintuitive: continuous receptor agonism, after an initial flare, desensitizes the pituitary gonadotropes and shuts down LH and FSH release, producing medical castration within weeks. Depot formulations are approved at 1-, 3-, 4-, and 6-month dosing intervals; the 6-month 45 mg intramuscular depot is the workhorse for long-term prostate cancer suppression. Additional approvals cover endometriosis, central precocious puberty, and uterine fibroids.

Goserelin (Zoladex), a related GnRH agonist delivered by subcutaneous biodegradable implant, was approved in 1989 for the same family of indications. Triptorelin (Trelstar) followed for advanced prostate cancer. The shared limitation across the agonist class is the initial testosterone flare, which can transiently worsen bone pain and urinary symptoms in metastatic prostate cancer patients during the first weeks.

Degarelix (Firmagon), approved in 2008, was the first GnRH antagonist for prostate cancer - directly blocking the receptor and producing castration-level testosterone suppression within days, with no flare. Relugolix (Orgovyx), approved in 2020, brought oral GnRH antagonism to the same indication and represents an important pharmacology shift: a non-peptide small molecule competing in what had been an exclusively peptide-injection space. Ganirelix and cetrorelix (Antagon, Cetrotide) are short-cycle GnRH antagonists approved for assisted reproduction, used to prevent premature LH surge during controlled ovarian stimulation.

The chronic-suppression toxicity profile for this class is well-characterized: hot flashes, bone density loss with prolonged use (the basis for bone-protective adjuncts in long-duration androgen deprivation), depression, sexual dysfunction, and an ongoing debate about cardiovascular risk that has not fully resolved. None of this is news. It's, however, the kind of long-tail toxicity profile that gets lost when "peptide therapy" is discussed as a uniformly benign category.

Octreotide (Sandostatin), approved in 1988, was the first synthetic somatostatin analog to clear the FDA. The indications are narrow and serious: acromegaly (suppressing GH and IGF-1 in patients with pituitary adenomas), carcinoid syndrome (controlling flushing and diarrhea from neuroendocrine tumors), and vasoactive intestinal peptide-secreting tumors. Long-acting depot formulations followed in the 1990s, extending dosing from multiple-daily subcutaneous injections to monthly intramuscular depots. An oral formulation, Mycapssa, was approved in 2020 for acromegaly maintenance - a real engineering achievement given the gut-degradation problem for an eight-amino-acid peptide.

Lanreotide (Somatuline Depot), approved in 2007, occupies the same therapeutic space with a slightly different receptor affinity profile (relatively higher SSTR2 selectivity) and a deep subcutaneous depot delivery. Pasireotide (Signifor), approved in 2012, was developed for the harder cases - Cushing's disease and acromegaly inadequately controlled on octreotide or lanreotide - and binds a broader range of somatostatin receptor subtypes (SSTR1, 2, 3, and 5). The trade-off is a clinically meaningful rate of hyperglycemia, severe enough that pasireotide is rarely the first choice when the alternatives work.

The class is genuinely useful in oncology beyond symptom control. Octreotide-based theranostics - radiolabeled analogs like Lu-177 dotatate (Lutathera, approved 2018) - deliver targeted radiotherapy to neuroendocrine tumors expressing somatostatin receptors. That's one of the cleaner examples of how peptide chemistry has migrated into precision oncology.

Salmon calcitonin has had a strange regulatory life. Approved in injectable form (Calcimar, Miacalcin) for Paget's disease, hypercalcemia, and postmenopausal osteoporosis decades ago, and in an intranasal formulation (Miacalcin Nasal Spray, Fortical) for postmenopausal osteoporosis specifically. The salmon variant is used rather than the human peptide because it binds the human calcitonin receptor with substantially higher affinity and longer functional duration.

The controversy is the cancer signal. A 2013 EMA review of long-term calcitonin trials found a small but consistent excess of malignancies in the calcitonin-treated arms versus placebo. The European response was to withdraw the nasal spray indication for osteoporosis entirely and restrict injectable use to short courses. FDA reviewed the same data and reached a softer conclusion, retaining approvals but updating labeling. The result is a drug that remains on the U.S. market for osteoporosis with a benefit-risk profile most endocrinologists now consider unfavorable compared with bisphosphonates, denosumab, or the parathyroid hormone analogs. It's not a drug I see prescribed often.

Desmopressin (DDAVP) is the V2-selective vasopressin analog approved in 1978 for central diabetes insipidus, primary nocturnal enuresis, and certain forms of von Willebrand disease and hemophilia A. The molecule is the natural arginine vasopressin with two modifications - desamination at position 1 and D-arginine substitution at position 8 - that extend the half-life from minutes to hours and remove the V1 vasoconstrictor activity. Approved formulations cover oral tablets, sublingual melts, intranasal sprays, and intravenous and subcutaneous injection. Eton Pharmaceuticals received approval for DESMODA, the first oral liquid formulation, on February 25, 2026, addressing a real clinical gap for pediatric and adult patients who can't reliably take tablets ^[9].

Hyponatremia is the adverse event that matters. Desmopressin is doing its job - water retention is the mechanism - and the resulting dilutional hyponatremia is the proximate cause of the serious adverse events reported with this drug, particularly in elderly patients or in pediatric enuresis use with excess fluid intake. The boxed warning on the intranasal enuresis formulations followed years of FAERS reports.

Vasopressin itself is approved (Vasostrict) for septic shock and post-cardiotomy vasodilatory shock, where the V1-mediated vasoconstriction is the therapeutic effect. Terlipressin (Terlivaz), a longer-acting vasopressin analog, was approved in 2022 for hepatorenal syndrome - a narrow but high-mortality indication where the alternatives are limited. Tolvaptan, often discussed in this category, is a small-molecule V2 antagonist and not a peptide.

Insulin is the original peptide drug. Approved in 1923, transitioned to NDA regulation in 2020 under BPCIA reforms, and now spans regular human insulin, NPH, and a generation of analogs engineered for specific pharmacokinetic profiles: rapid-acting (lispro, aspart, glulisine), long-acting (glargine, detemir, degludec), and ultra-rapid (faster aspart, lispro-aabc). Each modification - amino acid swaps at positions B28 and B29 for lispro, an extra arginine plus a glycine swap for glargine, a 16-carbon fatty acid attachment for degludec - solves a specific pharmacokinetic problem in the absorption and clearance curves.

The class is too large to inventory exhaustively here, but the regulatory point matters. Insulin biosimilars are now a real market following the 2020 transition. Semglee, the first interchangeable insulin biosimilar (to glargine), was approved in 2021 and has materially shifted the cost conversation for patients without good coverage. The peptide-drug framework has produced a generic-equivalent pathway for what was, for most of insulin's history, an effectively branded category.

The natriuretic peptide story is instructive in how it ended. Nesiritide (Natrecor), a recombinant form of human B-type natriuretic peptide, was approved in 2001 for acutely decompensated heart failure. The mechanism was elegant - vasodilation plus natriuresis through cGMP signaling - and the marketing was aggressive. Subsequent independent analysis and the ASCEND-HF trial in 2011 found no meaningful benefit on the harder endpoints and a possible signal for renal injury. The drug was effectively abandoned. Carperitide, the related atrial natriuretic peptide analog, is approved in Japan but never received U.S. approval. The category exists more as a cautionary tale about post-approval evidence than as a current treatment option.

Eptifibatide (Integrilin), the cyclic heptapeptide glycoprotein IIb/IIIa inhibitor approved in 1998 for acute coronary syndrome and percutaneous coronary intervention, remains in use though its role has narrowed considerably as P2Y12 inhibitors and modern anticoagulation strategies have evolved. Bivalirudin (Angiomax), a synthetic 20-amino-acid direct thrombin inhibitor approved in 2000, is similarly used as a procedural anticoagulant during PCI.

Oxytocin (Pitocin, Syntocinon) is approved for labor induction and milk let-down, full stop. The Phase 2 work on intranasal oxytocin for autism spectrum disorder (NCT01908205 and predecessors) has been mixed, and the molecule is not approved for any psychiatric or neurodevelopmental indication despite extensive consumer messaging suggesting otherwise.

Glucagon (Baqsimi nasal powder approved 2019, Gvoke autoinjector approved 2019, Dasiglucagon approved 2021) covers severe hypoglycemia rescue. The reformulations matter because injectable glucagon kits historically required reconstitution under stress; the newer single-step delivery devices have changed real-world use.

Enfuvirtide (Fuzeon), the HIV fusion inhibitor approved in 2003, was the first peptide antiretroviral. Twice-daily subcutaneous injection limited uptake, and oral integrase inhibitors largely displaced it, but it remains an option in salvage regimens.

Ziconotide (Prialt), a synthetic version of a cone snail venom peptide approved in 2004, is delivered intrathecally for severe chronic pain refractory to other options. The neuropsychiatric adverse effect profile is real, and use is concentrated in specialized pain programs.

Teriparatide (Forteo, approved 2002) and abaloparatide (Tymlos, approved 2017) are PTH and PTHrP analogs respectively, used for severe postmenopausal osteoporosis. Palopegteriparatide (Yorvipath), approved August 9, 2024, is a PEGylated parathyroid hormone analog with a ~60-hour half-life, approved for hypoparathyroidism - a chronic condition where prior peptide options required multiple daily doses and never delivered stable calcium control ^[1].

Glatiramer acetate (Copaxone), approved in 1996 for relapsing-remitting multiple sclerosis, is technically a synthetic peptide copolymer rather than a defined sequence, but the FDA regulates it under the peptide framework. Pegulicianine (Lumisight), approved in 2024, is a cathepsin-activated fluorescent peptide probe for intraoperative breast cancer imaging - an early entrant in the peptide-as-diagnostic category. Imetelstat (Rytelo), approved June 2024, is a telomerase inhibitor oligonucleotide that gets bundled with peptide approvals in industry counting but is structurally a thio-phosphoramidate oligo. Levacetylleucine (Aqneursa) and elamipretide (Forzinity, approved 2025 for Barth syndrome) round out the recent rare-disease approvals.

This is where the compounding world's legal architecture lives, and it's where most patient confusion originates.

Section 503A of the Federal Food, Drug, and Cosmetic Act permits a state-licensed pharmacy to compound a drug for an individual patient pursuant to a valid prescription, provided the bulk drug substance used meets one of three conditions: it's a component of an FDA-approved drug, it appears in a USP or NF monograph, or it's on FDA's published list of bulk drug substances that may be used in compounding under 503A. That third pathway - the 503A Bulks List - is the route by which substances without independent approval can enter compounding pharmacies legally.

FDA sorts nominated substances into categories. Category 1 contains substances FDA doesn't intend to take action against pending final rulemaking. Category 2 contains substances FDA has identified as raising real safety risks. Category 3 contains substances under evaluation. The mechanism by which a peptide gets added to Category 1 - the only category that allows legal compounding - runs through the Pharmacy Compounding Advisory Committee (PCAC), which reviews safety, effectiveness, and historical use data and recommends. FDA then publishes its decision.

The September 2023 reshuffling moved 17 peptides into 503A Category 2, effectively prohibiting compounding pending review. The list named most of the consumer-known compounded peptides: BPC-157, TB-500 (thymosin beta-4), CJC-1295 (with and without DAC), ipamorelin, thymosin alpha-1, AOD-9604, injectable GHK-Cu, melanotan II, KPV, selank, semax, epitalon, and others. FDA's stated concerns were a mix of unknown safety in the marketed routes and uses, lack of historical compounding tradition at the doses being marketed, and identity and purity concerns from the supply chain.

In April 2026 the agency removed 12 of those peptides from Category 2 - not because safety concerns were resolved, but because the original nominators withdrew their submissions. The practical effect was to move those peptides into a regulatory limbo: not on Category 1 (so not affirmatively permitted), not on Category 2 (so not affirmatively prohibited), pending PCAC review.

That review took place on July 23-24, 2026, covering seven of them: BPC-157, KPV, TB-500, MOTs-C, emideltide (DSIP), semax, and epitalon. The committee recommended six for the 503A bulks list and rejected only emideltide, in every case voting against the agency's own reviewers, who had proposed rejecting all seven. Free base and acetate salt were voted separately; the tallies were BPC-157, KPV and TB-500 8-6 with one abstention each, MOTs-C 7-5 with two, epitalon 7-4 with one, semax 8-5 with one, and emideltide down 6-7 with one. Our report on the meeting has the full record with timestamps into FDA's own webcast.

None of that has yet changed a single substance's legal status. Committee recommendations are non-binding, FDA has issued no final determination, and placement on the 503A list happens through rulemaking - a proposed rule, a comment period, a final rule - which has not started and carries no published timeline. A separate review of GHK-Cu, melanotan II, cathelicidin (LL-37), dihexa acetate, and PEG-MGF is scheduled to follow before February 2027.

What this means in plain language is that the peptides most heavily marketed by U.S. compounders through 2024 - BPC-157 above all - have never been on the 503A Bulks List in Category 1. They're not approved drugs. They're not, at present, legally compoundable bulk substances. The vendor landscape has operated in the gap between enforcement priorities and the absence of a final rule, and that gap is closing.

503B is a separate framework, created by the Drug Quality and Security Act of 2013 after the New England Compounding Center meningitis outbreak. A 503B outsourcing facility registers with FDA, follows cGMP, and can compound bulk quantities for office use without patient-specific prescriptions - but only from substances on the 503B Bulks List, or from substances on the FDA shortage list at the time of compounding.

The shortage carve-out is what enabled mass compounding of semaglutide and tirzepatide from 2022 through 2024. When both molecules came off the shortage list in early 2025, the 503B bulks pathway closed for them unless they were affirmatively added to the 503B Bulks List. The April 30, 2026 proposal to exclude semaglutide, tirzepatide, and liraglutide from that list was FDA stating, with no ambiguity, that it has found no clinical need for bulk compounding of these molecules. The public comment period closed June 29, 2026.

Gonadorelin acetate, the synthetic GnRH peptide previously approved as LutrePulse for induction of ovulation (since discontinued as a branded product), was added to 503B Category 1 and remains eligible for outsourcing-facility compounding - one of the cleaner examples of how a peptide can move from approved-drug status to compounding-list status when the commercial product exits the market but the clinical need persists.

A short inventory, since this is where most of the questions come from.

BPC-157 has never been an approved drug in any country. The published literature is overwhelmingly rodent work from a single research group in Croatia. No registered Phase 2 trial in humans exists. Category 2 from 2023 to April 2026; recommended for the 503A list by the PCAC in July 2026 on an 8-6-1 vote, but still not on it, since FDA has not acted on that recommendation.

TB-500 / thymosin beta-4 has limited human data in a small number of cardiac and ophthalmologic studies and no approval. Pre-clinical interest is real; the clinical case is unmade.

CJC-1295 and ipamorelin are growth hormone secretagogues developed by industry programs that did not complete development. Neither has an approval. The stacked CJC-1295/ipamorelin combination heavily marketed by anti-aging clinics has no human controlled-trial evidence supporting either safety or efficacy at the marketed doses.

Thymosin alpha-1 (Zadaxin) is approved in roughly 35 countries for hepatitis B and as an adjunct in cancer immunotherapy. It's not approved in the United States, and the U.S. compounding pathway is not currently open.

AOD-9604 is a fragment of growth hormone marketed for fat loss; no approval, no convincing Phase 2 data, weak mechanism.

Melanotan II has been associated with serious adverse events including nausea, hypertension, and reports of melanoma; no approval anywhere.

Selank, semax, and epitalon are Russian-origin peptides with research-use status in their country of origin and no approval in any Western regulatory framework.

The FDA's 2023 actions and the 2026 PCAC review process can be read two ways. The compounding-industry framing is regulatory overreach against a class of substances with long safe-use histories. The agency framing is that the rapid growth of consumer-facing peptide marketing - with the dose levels, routes, and indications drifting far from any historical compounding tradition - created a population safety problem that the existing framework was not designed to handle. Both framings contain truth. The honest read of the evidence is that for most peptides in the consumer market, the controlled-trial data needed to support routine human use doesn't exist, and the question of what the regulatory pathway should be is downstream of that gap.

The approved peptide drugs, organized by category. This is not exhaustive - the full inventory runs to about 130 entities - but it covers the principal classes and the most clinically real approvals.