What Peptides Are and Why Everyone Is Suddenly Talking About Them
Peptides are short chains of amino acids, the same building blocks that make up proteins. A protein can contain hundreds or thousands of amino acids, while a peptide usually has just a few to a few dozen. The body uses them as messengers: many hormones are actually peptides. These include insulin and GLP-1, a hormone released in the gut after a meal that helps regulate blood sugar and the feeling of fullness.
It's precisely because peptides can mimic the body's natural signals that they make interesting medicines. For a long time, though, they had one big drawback: the digestive tract breaks them down just like the protein in food, so most of them have to be injected. That was one reason they stayed somewhat on the sidelines. Over the past five years, that has changed fundamentally.
The Starting Point: The Market in 2021
A good snapshot of the situation at the time comes from a review by Markus Muttenthaler's team at the University of Vienna, published in February 2021 in the prestigious journal Nature Reviews Drug Discovery. The authors counted:
- more than 80 approved peptide drugs on the global market,
- more than 150 in clinical development and another 400 to 600 in early-stage research,
- peptides accounting for roughly 5% of the global pharmaceutical market, with sales of more than $50 billion a year,
- about 90% of peptide drugs needing to be given by injection.
So peptides were nothing new. But they were a stable, fairly niche field. Nobody expected how quickly that would change.
2021: Wegovy and the Start of a New Era in Obesity Treatment
The turning point came on June 4, 2021. That day, the US Food and Drug Administration (FDA) approved Wegovy, containing the active ingredient semaglutide, for chronic weight management. The agency itself pointed out that it was the first new weight-management drug approved since 2014.
Semaglutide is a peptide that mimics the hormone GLP-1. It was already being used for type 2 diabetes under the name Ozempic. In clinical trials in people with obesity, however, it produced weight loss that no drug had delivered before.
Europe followed six months later. The European Medicines Agency (EMA) recommended Wegovy for approval, and on January 6, 2022, it received a marketing authorization valid throughout the European Union.
Tirzepatide and the Battle of Two Giants
The second milestone was tirzepatide from the US company Eli Lilly. Unlike semaglutide, it mimics two gut hormones at once, GIP and GLP-1. The FDA approved it on May 13, 2022, as Mounjaro for type 2 diabetes, and on November 8, 2023, as Zepbound for chronic weight management. In the European Union, Mounjaro has been authorized since September 15, 2022, and today it can be used both for diabetes and for weight management.
The best way to show how much demand there is for these drugs is with figures from both manufacturers' annual reports:
| Metric | 2021 | 2025 |
|---|---|---|
| Novo Nordisk total sales | DKK 140.8 billion | DKK 309.1 billion |
| Of which obesity care (Wegovy, Saxenda) | DKK 8.4 billion | DKK 82.3 billion |
| Ozempic | DKK 33.7 billion | DKK 127.1 billion |
| Eli Lilly total revenue | $28.3 billion | $65.2 billion |
| Mounjaro + Zepbound | not yet approved | $36.5 billion |
The Danish company Novo Nordisk's obesity care sales grew roughly tenfold in four years. Eli Lilly more than doubled its total revenue, and tirzepatide became its best-selling medicine. Novo Nordisk also reports that more than 45 million people used its diabetes and obesity medicines last year.
We covered tirzepatide in detail in our article Tirzepatide: How It Works and What the Trials Showed.
Demand Outpaced Supply
Nobody expected this level of demand, not even the manufacturers themselves. Making peptides is technically demanding, and a new factory can't be built in a few months. The result was several years in which the drugs weren't available in the quantities people wanted.
In the US, the FDA added Wegovy to its drug shortage list in March 2022, Ozempic in August 2022 and tirzepatide in December 2022, citing surging demand. It officially removed tirzepatide from the list in fall 2024 (with final confirmation on December 19, 2024) and semaglutide on February 21, 2025, when it concluded that supply now meets demand.
In Europe, the EMA coordinated the response. According to its documents, Ozempic shortages had been ongoing since 2022 and also affected other GLP-1 medicines. The agency attributes them to a combination of rising demand and limited manufacturing capacity. European authorities worked with manufacturers to redistribute stock between countries and to limit new treatment starts so that people already on the medicine wouldn't go without.
Manufacturers responded with investments on a scale the pharmaceutical industry hadn't seen in a long time. In November 2023, Novo Nordisk announced that it would invest more than DKK 42 billion in expanding production in Kalundborg, Denmark, alone, mainly in making active ingredients. The new facilities are due to come online gradually from the end of 2025 through 2029. Europe thus remains one of the world's main hubs for producing peptide drugs.
From Injections to Pills
Remember how, in 2021, 90% of peptide drugs had to be injected? Here, too, things have moved quickly.
On December 22, 2025, the FDA approved Wegovy in pill form, the first oral GLP-1 medicine approved specifically for weight management. In the key OASIS 4 trial, participants lost an average of about 17% of their body weight over 64 weeks, and one in three lost 20% or more. The manufacturer announced a US launch for January 2026.
Europe once again followed shortly after. The EMA's Committee for Medicinal Products for Human Use (CHMP) recommended the pill for approval on May 22, 2026, and the European Commission approved it in summer 2026.
For peptides, this is a big deal. Getting a fragile chain of amino acids through the stomach so that it's absorbed into the bloodstream was long considered extremely difficult. Pills may also be more convenient for many people, and they don't require injection pens.
More Than Weight Loss: The Heart, Sleep and Rare Diseases
The second big change is that peptide drugs are no longer seen only as "weight-loss drugs". There's growing evidence that they also help with health problems linked to excess weight.
- Heart and blood vessels: The SELECT trial, published in 2023 in the New England Journal of Medicine, followed 17,604 people with overweight or obesity and heart disease who did not have diabetes. Semaglutide lowered their risk of heart attack, stroke or cardiovascular death by about 20%. Based on these data, the FDA expanded Wegovy's approval in March 2024 to include cardiovascular risk reduction.
- Sleep apnea: In December 2024, tirzepatide became the first drug approved in the US to treat obstructive sleep apnea in adults with obesity.
- Rare diseases: Peptides aren't just GLP-1 drugs. According to the annual "FDA TIDES Harvest" review in the journal Pharmaceuticals, the FDA approved a total of 34 peptide drugs between 2016 and 2024. In 2025, they were joined by elamipretide for a rare inherited disorder called Barth syndrome.
What started as a narrow group of diabetes drugs has become a broad field of medicine that reaches into cardiology, sleep medicine and the treatment of rare diseases.
The US vs. Europe: Two Different Approaches
The peptide market is growing on both sides of the Atlantic, but it looks quite different.
The United States is the largest market and the one changing fastest. Telehealth plays a big role there, letting people arrange treatment online. According to a November 2025 survey by the independent health policy organization KFF, 12% of American adults are currently taking a GLP-1 drug, roughly one in eight, and nearly one in five have taken one at some point. Another US feature is compounded drugs, prepared directly by pharmacies based on a prescription. During the shortages, the law temporarily allowed pharmacies to compound semaglutide and tirzepatide this way. Once the shortages ended, the FDA set transition periods, which expired in spring 2025.
Europe takes a more cautious approach that runs more through public healthcare. Medicines for the whole European Union are assessed centrally by the EMA and authorized by the European Commission, but each country decides for itself who gets them reimbursed. The UK is a good example. In December 2024, the UK's National Institute for Health and Care Excellence (NICE) recommended tirzepatide for obesity treatment within the National Health Service (NHS). In theory, around 3.4 million people in England would be eligible, so treatment is being rolled out gradually: about 220,000 patients with the greatest clinical need are expected to receive it in the first three years. The full rollout could take up to 12 years.
The European approach is slower, but it puts strong emphasis on getting the medicines first to those who will benefit most, and on keeping costs manageable for the system.
Peptides Beyond Approved Drugs: From a Ban to a Regulated Pathway
Alongside drugs like semaglutide, interest has also grown in other peptides that are not approved as medicines and are studied mainly in research. These include BPC-157, TB-500 and MOTS-c, a molecule the body makes in its own muscles. Here, too, a lot has changed over the past five years, mainly in the US.
- 2023: The FDA placed a group of peptides, including BPC-157, in what's known as Category 2. This meant pharmacies were not allowed to compound them. The agency cited a lack of human safety data and difficulties in verifying quality.
- April 2026: The FDA announced it would remove seven peptides from Category 2 and have an advisory committee review them. These were BPC-157, KPV, TB-500, MOTS-c, DSIP (emideltide), Semax and Epitalon.
- July 2026: The FDA advisory committee recommended allowing six of them.
- October 28, 2026: The US Department of Health and Human Services (HHS) announced it would not take action against pharmacies that compound six peptides (BPC-157, TB-500, MOTS-c, KPV, Semax and Epitalon) for an individual patient with a prescription. The conditions include strict quality rules: a bulk substance from an FDA-registered facility, a certificate of analysis, manufacturing under good manufacturing practice (GMP) and reporting of serious adverse events. According to TIME, this market could reach as much as $3.3 billion.
Importantly, this is not a drug approval. It's a regulated pathway that brings existing demand under oversight and puts the focus on quality and traceability. In Europe, the status of these substances hasn't changed: they are not authorized as medicines and are used for research purposes. But developments in the US often serve as a benchmark for the debate elsewhere, so they're worth following.
We wrote about MOTS-c in detail in our article MOTS-c: The Exercise Peptide Made by Your Mitochondria. We sum up the latest developments every week in our weekly peptide news.
Timeline: Five Years at a Glance
- February 2021: A review in Nature Reviews Drug Discovery counted more than 80 approved peptide drugs.
- June 4, 2021: The FDA approved Wegovy (semaglutide) for weight management.
- January 6, 2022: Wegovy received marketing authorization throughout the EU.
- May 13, 2022: The FDA approved tirzepatide (Mounjaro) for type 2 diabetes.
- March–December 2022: Due to huge demand, semaglutide and tirzepatide were added to the US drug shortage list.
- September 15, 2022: Mounjaro was authorized in the EU.
- 2023: The FDA placed BPC-157 and other peptides in Category 2.
- November 8, 2023: The FDA approved Zepbound (tirzepatide) for weight management.
- November 2023: The SELECT trial showed that semaglutide lowers the risk of cardiovascular events. Novo Nordisk announced an investment of more than DKK 42 billion in production in Denmark.
- March 2024: The FDA expanded Wegovy's approval to include cardiovascular risk reduction.
- December 2024: Tirzepatide was approved in the US for sleep apnea. The FDA approved the first generic version of liraglutide, an older GLP-1 peptide. NICE recommended tirzepatide for the UK's NHS.
- February 21, 2025: The FDA declared the semaglutide shortage over.
- December 22, 2025: The FDA approved Wegovy in pill form.
- April–July 2026: The FDA removed BPC-157 and other peptides from Category 2, and an advisory committee recommended allowing six of them.
- May–July 2026: The Wegovy pill was recommended and approved in the EU.
- October 28, 2026: HHS opened a regulated pathway for pharmacies to six peptides. On the same day, Eli Lilly announced that retatrutide had outperformed Ozempic in a head-to-head trial.
Where the Market Is Heading Next
If the past five years have shown anything, it's that peptides still have a lot of untapped potential. More changes are on the horizon:
- Stronger and combination drugs: Eli Lilly's retatrutide mimics three hormones at once (GIP, GLP-1 and glucagon). In a trial whose topline results the company released in October 2026, it led to more than twice as much weight loss as Ozempic in people with type 2 diabetes. Novo Nordisk is developing CagriSema, a combination of semaglutide and cagrilintide. Both are still awaiting approval.
- Generics: Older GLP-1 peptides such as liraglutide already have cheaper generic versions in the US. This is gradually widening access to treatment.
- More convenient forms: Pills and new ways of administering drugs could open up treatment to people who have avoided injections.
- Focus on quality: Whether it's approved medicines or peptides under a regulated pathway, authorities on both sides of the Atlantic are increasingly insisting on traceable sourcing and certified quality.
In five years, peptides have moved from the fringes of the pharmaceutical industry to its center. And it looks like this is only the beginning.
Frequently Asked Questions
What is a peptide, in simple terms?
A short chain of amino acids. It's essentially a "mini protein" that the body often uses as a signal. Insulin and the hormone GLP-1 are examples of peptides.
Why has the peptide market grown so fast?
Mainly because of drugs that mimic the hormone GLP-1, such as semaglutide and tirzepatide. They showed a strong effect in treating obesity and type 2 diabetes, and later benefits for the heart as well. Novo Nordisk's obesity care sales rose roughly tenfold between 2021 and 2025.
How do the US and European markets differ?
The US market is larger and changes faster, with telehealth and pharmacy-compounded drugs playing a big role. In Europe, medicines are authorized centrally for the whole EU, but each country decides on reimbursement. Rollout is therefore slower and focuses more on patients with the greatest need.
Are peptides like BPC-157 or MOTS-c approved as drugs?
No. Since October 2026, US pharmacies may compound them under strict conditions for an individual patient, but this is not a drug approval. In Europe, they are not authorized as medicines and are used for research.
Will peptide drugs be available as pills?
They already are. The FDA approved Wegovy in pill form in December 2025, and the European Union followed in 2026. Most peptide drugs, however, are still given by injection.
Where can I find the latest peptide news?
We sum it up every week in our peptide news, where we pick the most interesting developments from Europe and the US.
Sources
- Muttenthaler M. et al. "Trends in peptide drug discovery". Nature Reviews Drug Discovery, 2021; 20: 309–325. DOI: 10.1038/s41573-020-00135-8: nature.com
- AlShaer D., Al Musaimi O., Albericio F., de la Torre B. G. "2025 FDA TIDES (Peptides and Oligonucleotides) Harvest". Pharmaceuticals, 2026; 19(2): 244: mdpi.com
- FDA – FDA Approves New Drug Treatment for Chronic Weight Management, First Since 2014 (June 4, 2021): biospace.com
- FDA – FDA Approves Novel, Dual-Targeted Treatment for Type 2 Diabetes (May 13, 2022): biospace.com
- Eli Lilly – FDA Approves Lilly's Zepbound (tirzepatide) for Chronic Weight Management (November 8, 2023): investor.lilly.com
- EMA – Wegovy, EPAR: ema.europa.eu
- EMA – Mounjaro, EPAR: ema.europa.eu
- Lincoff A. M. et al. "Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes". New England Journal of Medicine, 2023; 389: 2221–2232 (ACC summary): acc.org
- Novo Nordisk – Wegovy approved in the US for cardiovascular risk reduction (March 2024): novonordisk.com
- Novo Nordisk – Financial results for 2021 (Form 6-K, SEC): sec.gov
- Novo Nordisk – Financial results for 2025 (Form 6-K, SEC): sec.gov
- Eli Lilly – Financial results for 2021 (Form 8-K, SEC): sec.gov
- Eli Lilly – Lilly reports fourth-quarter 2025 financial results (February 4, 2026): lilly.gcs-web.com
- Drug Topics – FDA Declares Shortage of Ozempic, Wegovy Resolved (February 21, 2025): drugtopics.com
- Pharmacy Times – FDA Affirms Tirzepatide Shortage Resolved, Sets Transition Period for Compounding (December 20, 2024): pharmacytimes.com
- EMA – Overview of the supply situation of GLP-1 receptor agonists (presentation): ema.europa.eu
- Novo Nordisk – Novo Nordisk invests more than 42 billion Danish kroner in expansion of manufacturing facilities in Kalundborg (November 10, 2023): novonordisk.com
- Pharmaceutical Commerce – FDA Approves Novo Nordisk's Wegovy Pill (December 2025): pharmaceuticalcommerce.com
- Novo Nordisk – CHMP positive opinion for Wegovy pill (May 22, 2026): novonordisk.com
- Indian Pharma Post – Novo Nordisk wins EU approval for Wegovy pill in Europe (July 17, 2026): indianpharmapost.com
- HealthDay – FDA Approves First Generic Liraglutide Once-Daily Injection (December 26, 2024): healthday.com
- NICE – NICE describes how weight loss drug tirzepatide will be rolled out (December 23, 2024): nice.org.uk
- KFF – Poll: 1 in 8 Adults Say They Are Currently Taking a GLP-1 Drug (November 14, 2025): kff.org
- Polsinelli – Tiny Chains, Big Changes? What FDA's Latest Actions Mean for Peptide Compounding (April 22, 2026): polsinelli.com
- ABC News – Some wellness peptides will become widely available, HHS says (October 28, 2026): abcnews.com
- TIME – The Peptide Rush Has Begun (October 28, 2026): time.com
- Pharmacy Times – FDA Approves Tirzepatide as First Treatment for Moderate to Severe Obstructive Sleep Apnea in Adults With Obesity (December 2024): pharmacytimes.com
- Eli Lilly – Lilly's retatrutide delivered greater A1C reduction and more than double the weight loss of Ozempic's highest approved dose in head-to-head trial (October 28, 2026): investor.lilly.com