The FDA has approved more than 80 peptide-based drugs, spanning diabetes management, weight loss, osteoporosis, hormone disorders, and more. Some are household names like semaglutide (Ozempic) and tirzepatide (Mounjaro), while others work quietly in hospital settings or rare disease treatment. Here’s a practical breakdown of the major categories and what each peptide is approved to treat.
How the FDA Defines a Peptide
For regulatory purposes, the FDA considers any chain of 40 or fewer amino acids to be a peptide. Chains between 41 and 99 amino acids that are made entirely by chemical synthesis fall into a middle category called “chemically synthesized polypeptides.” Anything above 40 amino acids is generally classified as a protein. This distinction matters because it determines how a drug is regulated, whether as a conventional drug or as a biological product with a different approval pathway.
Diabetes and Weight Management
This is the largest and most commercially prominent category of FDA-approved peptides. These drugs either mimic gut hormones that stimulate insulin release and reduce appetite, or they work alongside insulin to improve blood sugar control.
Semaglutide is approved under two brand names: Ozempic for type 2 diabetes and Wegovy for chronic weight management. Tirzepatide follows the same dual-approval pattern, sold as Mounjaro for type 2 diabetes and Zepbound for weight loss. Zepbound was approved in November 2023 for adults with a BMI of 30 or higher, or a BMI of 27 or higher with at least one weight-related condition like high blood pressure or high cholesterol. Tirzepatide works by activating receptors for two gut hormones simultaneously, which reduces appetite and food intake.
Other approved diabetes peptides include:
- Exenatide (Byetta): improves blood sugar control in type 2 diabetes
- Liraglutide (Victoza): manages type 2 diabetes and reduces cardiovascular risk
- Dulaglutide (Trulicity): manages type 2 diabetes and reduces cardiovascular risk
- Lixisenatide (Adlyxin): improves blood sugar control in type 2 diabetes
- Pramlintide (Symlin): used alongside insulin for type 1 and type 2 diabetes
Albiglutide (Tanzeum) was also approved for type 2 diabetes but was discontinued in 2017. Insulin itself, the original peptide drug, remains the foundation of diabetes treatment and has been available in various formulations for decades.
Osteoporosis
Two peptide drugs are approved to treat osteoporosis by stimulating new bone growth rather than simply slowing bone loss. Teriparatide (Forteo) is a fragment of parathyroid hormone, and abaloparatide (Tymlos) is a synthetic version of a related hormone. Both are approved for postmenopausal women at high risk for fracture, meaning they’ve already had an osteoporotic fracture, have multiple risk factors, or haven’t responded to other treatments.
One important limitation: cumulative use of teriparatide and abaloparatide for more than two years during a patient’s lifetime is not recommended. These are typically prescribed as a defined course of treatment, not a lifelong therapy.
Hormone Disorders and Critical Care
Several FDA-approved peptides are natural hormones or close copies used to replace what the body isn’t producing or to manage acute medical situations:
- Oxytocin (Syntocinon): induces uterine contractions during labor and supports milk ejection
- Vasopressin (Vasostrict): raises blood pressure in adults with vasodilatory shock
- Glucagon (Baqsimi): treats dangerously low blood sugar and serves as an antidote for certain medication overdoses
- Calcitonin (Miacalcin): controls blood calcium levels
- Angiotensin II (Giapreza): raises blood pressure in distributive shock
- Parathyroid hormone (Natpara): controls low calcium in people with hypoparathyroidism
- Corticotropin (H.P. Acthar): treats steroid-responsive disorders, multiple sclerosis flares, and infantile spasms
In 2024, the FDA approved palopegteriparatide (Yorvipath) as a new treatment for hypoparathyroidism, adding another option for people whose parathyroid glands don’t produce enough hormone on their own.
Growth Hormone Pathway
Rather than giving growth hormone directly, some approved peptides stimulate the body’s own production or address related deficiencies. Sermorelin (Geref) was approved in 1997 for growth hormone deficiency in children with growth failure. Tesamorelin (Egrifta) is approved specifically to reduce excess abdominal fat in people living with HIV who have lipodystrophy. Macimorelin (Macrilen) serves a diagnostic purpose, helping clinicians confirm whether an adult has growth hormone deficiency. Mecasermin (Increlex) treats growth failure in children with severe deficiency of insulin-like growth factor 1.
Gastrointestinal Conditions
Peptide-based drugs also treat chronic digestive problems. Plecanatide (Trulance) is approved for chronic idiopathic constipation in adults, defined as fewer than three bowel movements per week without meeting the criteria for irritable bowel syndrome with constipation. Linaclotide (Linzess) treats both chronic constipation and IBS with constipation. Both work by activating receptors in the intestinal lining that increase fluid secretion and speed up gut movement. Secretin (ChiRhoStim) has a more specialized role, used to assess pancreatic function and regulate gastric acid.
Sexual Health and Rare Diseases
Bremelanotide (Vyleesi) is approved to treat hypoactive sexual desire disorder in premenopausal women. It’s a self-administered injection used as needed before anticipated sexual activity, and it’s specifically intended for women who previously had normal sexual desire but developed a persistent lack of it regardless of partner, situation, or type of stimulation.
Afamelanotide (Scenesse) treats a rare condition called erythropoietic protoporphyria, where exposure to light causes severe pain. The drug increases the amount of time patients can spend in light without experiencing pain.
Cyclosporine (Sandimmune), while sometimes grouped with peptides due to its cyclic peptide structure, is widely used as an immunosuppressant to prevent organ rejection after transplants and to treat autoimmune conditions.
Popular Peptides That Are Not FDA-Approved
Many peptides sold through compounding pharmacies, online retailers, or wellness clinics have no FDA approval for any medical use. The most commonly searched examples are BPC-157 and TB-500 (a fragment of thymosin beta-4), both marketed for injury recovery and tissue repair. The FDA has flagged both as potentially posing significant safety risks.
For BPC-157, the agency has stated it has identified “no, or only limited, safety-related information” for the ways people typically use it, and lacks sufficient evidence to know whether it causes harm in humans. For TB-500, the FDA has found no human exposure data at all and cannot determine its safety profile. Both substances are currently under review, with FDA advisory committee consultations scheduled for mid-2026.
Other unapproved peptides awaiting regulatory review include:
- Melanotan II: used for tanning and sometimes marketed for sexual dysfunction
- Epitalon: marketed as an anti-aging peptide
- Semax: promoted for cognitive enhancement
- GHK-Cu (injectable): promoted for skin and tissue repair
- MOTs-C: marketed for metabolic health and exercise performance
- KPV: marketed for inflammation
None of these have been approved for any indication. The FDA’s planned advisory committee meetings in 2026 and 2027 will evaluate whether any of these substances should be permitted for use by compounding pharmacies, but that process involves safety review, not efficacy approval. Even if eventually allowed for compounding, they would not carry the same level of evidence as fully approved drugs.