Approval belongs to a product
An FDA approval covers a particular product: its maker, its form, its strengths and the uses written in Section 1 of its label. The same molecule can sit in two products with different approvals.
Liraglutide is a clear example. The Victoza® label covers blood sugar control in type 2 diabetes from age 10 and, in adults who have both type 2 diabetes and established heart disease, lowering the risk of heart attack, stroke and cardiovascular death [9]. The Saxenda® label covers weight reduction and long-term maintenance alongside diet and activity [10]. Both labels say their liraglutide should not be combined with other liraglutide-containing products [9][10].
Where the FDA draws the peptide line
On its page about the “deemed to be a license” provision, the FDA describes peptides as polymers of 40 or fewer amino acids. Longer chains count as proteins. Under the Biologics Price Competition and Innovation Act, protein products that had been approved as ordinary drugs, such as insulin and insulin analogues, human growth hormone, pancreatic enzymes and reproductive hormones, were deemed to be biological product licences on March 23, 2020 [1].
So insulin, often described as a peptide hormone, is regulated in the United States as a protein. The FDA notes that this change does not affect peptides [1].
Examples from the labels
The table gathers the examples in this article. Section 11 of a label describes the molecule; Section 1 lists what it is approved for. The uses are shortened here, so the label itself is the place to read them in full.
| Medicine (active ingredient) | What the label says the molecule is | Approved for (shortened) |
|---|---|---|
| Ozempic®, Wegovy®, Rybelsus® (semaglutide) | A GLP-1 analogue whose peptide backbone is produced by yeast fermentation [4] | Type 2 diabetes (Ozempic®, Rybelsus®); weight reduction and cardiovascular risk reduction (Wegovy®), among other uses [4][6][7] |
| Mounjaro®, Zepbound® (tirzepatide) | A molecule built on the GIP sequence [5] | Type 2 diabetes (Mounjaro®); weight reduction and obstructive sleep apnoea with obesity (Zepbound®) [5][8] |
| Victoza®, Saxenda® (liraglutide) | An analogue with 97% amino acid sequence homology to human GLP-1 [9][10] | Type 2 diabetes from age 10 (Victoza®); weight reduction (Saxenda®) [9][10] |
| Forteo (teriparatide) | The first 34 amino acids of human parathyroid hormone, made in E. coli [11] | Osteoporosis at high risk of fracture [11] |
| Gattex® (teduglutide) | A 33-amino-acid GLP-2 analogue, made in E. coli [13] | Short bowel syndrome in people from age 1 who depend on parenteral support [13] |
| Egrifta SV® (tesamorelin) | The 44-amino-acid sequence of human growth hormone-releasing factor with an added hexenoyl group [14] | Excess abdominal fat in adults with HIV and lipodystrophy [14] |
| NovoLog® (insulin aspart) | A human insulin analogue differing at one amino acid, B28 [12] | Blood sugar control in adults and children with diabetes [12] |
GLP-1 medicines that are peptides
- Semaglutide: Ozempic® injection and tablets for type 2 diabetes, Rybelsus® tablets for type 2 diabetes, and Wegovy® injection and tablets for weight reduction and cardiovascular risk reduction, among other uses in each label [4][6][7]. The labels describe a GLP-1 analogue whose peptide backbone is produced by yeast fermentation [4].
- Tirzepatide: Mounjaro® for type 2 diabetes and, in its current label, for lowering the risk of serious heart and blood vessel events in high-risk adults with that condition; Zepbound® for weight reduction and, in adults with obesity, for moderate to severe obstructive sleep apnea [5][8]. The labels describe a molecule built on the GIP sequence [5].
- Liraglutide: Victoza® and Saxenda®, as described above [9][10].
- Not every GLP-1 medicine is a peptide: the Foundayo™ label describes orforglipron with a chemical formula and name rather than an amino acid sequence [16].
Peptides for bone and gut
Not every approved peptide is a weight or diabetes medicine. The Forteo label describes teriparatide as a recombinant analogue of human parathyroid hormone: its sequence is identical to the first 34 amino acids of the 84-amino-acid hormone, and it is made using a strain of E. coli modified by recombinant DNA technology [11]. Its label covers osteoporosis at high risk of fracture in postmenopausal women and in men, and osteoporosis linked to long-term glucocorticoid use [11].
The Gattex® label describes teduglutide as a 33-amino-acid analogue of glucagon-like peptide-2 (GLP-2), also made in E. coli [13]. It is a different hormone from GLP-1 and a different use: the label covers short bowel syndrome in adults and children aged 1 year and older who depend on parenteral support [13]. At 34 and 33 amino acids, both sit below the FDA’s 40-amino-acid line.
Just over the line: tesamorelin and insulin
Tesamorelin, the active ingredient of Egrifta SV®, is an analogue of growth hormone-releasing factor. Its label describes the 44-amino-acid sequence of the human hormone with a hexenoyl group attached, and its listing in the US National Library of Medicine’s DailyMed shows a biologics licence application number rather than a new drug application [14]. That fits the FDA’s line: at 44 amino acids, tesamorelin is a protein in regulatory terms, even though it is often called a peptide.
Insulin aspart, sold as NovoLog®, is the classic example. Its label describes a rapid-acting human insulin analogue that differs from regular human insulin by a single amino acid, with aspartic acid in place of proline at position B28, produced in baker’s yeast by recombinant DNA technology [12]. It is an approved medicine, but insulin is on the FDA’s list of protein products, so insulin products are regulated as biological products rather than as peptide drugs [1].
Approvals can end
An approval is not permanent. Exenatide, the first GLP-1 medicine, shows this: in August 2025 the FDA announced that it was withdrawing approval of the application for Byetta®, at the holder’s request because the product was no longer marketed, with effect from 3 September 2025 [15]. The exenatide article covers what that means.
This is another reason the label, not the molecule, is what counts: a product that was approved once may no longer be, and a pharmacist can confirm what is currently available.
Reading a label to see what you have
- Section 1, Indications and Usage, lists exactly what the product is approved for.
- Section 11, Description, says what the molecule is and often how it is made, such as yeast fermentation or recombinant DNA.
- Section 12, Clinical Pharmacology, explains how it acts and how long it stays in the body.
- Drugs@FDA lists most drug products approved since 1939, with labels for many of them, and is the FDA’s own place to check a specific product [2].
What does not count as approved
Being a peptide, or containing the same active ingredient as an approved medicine, does not make a product approved. According to the FDA, compounded drugs are not FDA approved, so nobody at the agency checks their safety, effectiveness or quality before they reach patients [3]. The FDA has also warned companies selling unapproved GLP-1 products falsely labelled “for research purposes” [3].
The same applies to peptides with no approved product at all, such as those sold online for recovery or body composition. The article on “research use only” peptides covers what the FDA says about them. A pharmacist can confirm what a product is and which label applies.
Ozempic®, Wegovy®, Rybelsus®, Saxenda®, Victoza® and NovoLog® are registered trademarks of Novo Nordisk A/S. Mounjaro® and Zepbound® are registered trademarks of Eli Lilly and Company, and Foundayo™ is a trademark of Eli Lilly and Company. Forteo is marketed by Lilly USA, LLC. Gattex® is a registered trademark of Takeda Pharmaceuticals U.S.A., Inc. Egrifta SV® is a registered trademark of Theratechnologies Inc. Byetta® is a trademark of the AstraZeneca group of companies. PepLabo is not affiliated with or endorsed by Novo Nordisk, Eli Lilly and Company, Takeda, Theratechnologies or AstraZeneca.
