This post will be different from the usual post (focused on a company fundamentals). I'll aim to dive deeper on what is exactly diabete, how GLP-1 drugs solve for it (and accidentally solve for obesity, which is a driving factor of diabete).
Next, I will shift to how Novo Nordisk products compare versus its competition (mainly Eli Lilly) by looking at its drug effectiveness, side effects and convenience.
Diabete 101
Let's start with some science primers. Glucose is an energy source for our cells, which transforms glucose into energy. When we eat, and let glucose enter our body, the pancreas is in charge of monitoring and regulating the glucose by releasing 2 hormones: insulin and glucagon.
- Insulin is released by the beta-cells of pancreas and acts like a key to glucose into our cells (thus reducing glucose presence in our blood)
- Glucagon has the opposite effect and is released by the alpha-cells of the pancreas. In period of low glucose, such as fasting, it raises glucose by signaling the liver (which acts as a store) to release glucose.
Now, diabete can take two forms: type 1 and type 2.
Diabete type 1 is a disease in which the immune system mistakenly attacks the pancreas' beta cells which make insulin. Without enough insulin, glucose builds up in the body. Patients need insulin injections since their body can't produce it.
Diabete type 2 is a disease in which the pancreas still produces insulin but the body becomes resistant to it (cells ignore the insulin's role as a key). This insulin resistance is due to inflammation, fat buildup or stress signals inside the cells. This leads to high blood sugar, which leads to the pancreas continuously producing insulin and ultimately to the pancreas metabolic dysfunction.
How does GLP-1 work
GLP-1 stands for glucagon-like peptide-1 and is a gut hormone that boosts insulin's effectiveness again resistance. GLP-1 agonists (like Novo's semaglutide which we will review later) helps by slowing digestion, which prevents blood sugar spikes and reduces the demand for insulin. GLP-1 also cuts inflammation and eases cell stress, making cells more responsive to insulin. It also suppresses glucagon secretion from alpha cells, which curbs excess glucose in the blood. As you might have understood, the result is much lower stress on the pancreas and much better glucose regulation inside the body, which is a perfect outcome for diabete type 2 patients.
You might see now why GLP-1 drugs are not just a band-aid solution: by lowering the stress on the pancreas and improving the cells' resistance to insulin, these address the deeper causes of diabete type 2.
Next, I will shift to how Novo Nordisk products compare versus its competition (mainly Eli Lilly) by looking at its drug effectiveness, side effects and convenience.
Diabete 101
Let's start with some science primers. Glucose is an energy source for our cells, which transforms glucose into energy. When we eat, and let glucose enter our body, the pancreas is in charge of monitoring and regulating the glucose by releasing 2 hormones: insulin and glucagon.
- Insulin is released by the beta-cells of pancreas and acts like a key to glucose into our cells (thus reducing glucose presence in our blood)
- Glucagon has the opposite effect and is released by the alpha-cells of the pancreas. In period of low glucose, such as fasting, it raises glucose by signaling the liver (which acts as a store) to release glucose.
Now, diabete can take two forms: type 1 and type 2.
Diabete type 1 is a disease in which the immune system mistakenly attacks the pancreas' beta cells which make insulin. Without enough insulin, glucose builds up in the body. Patients need insulin injections since their body can't produce it.
Diabete type 2 is a disease in which the pancreas still produces insulin but the body becomes resistant to it (cells ignore the insulin's role as a key). This insulin resistance is due to inflammation, fat buildup or stress signals inside the cells. This leads to high blood sugar, which leads to the pancreas continuously producing insulin and ultimately to the pancreas metabolic dysfunction.
How does GLP-1 work
GLP-1 stands for glucagon-like peptide-1 and is a gut hormone that boosts insulin's effectiveness again resistance. GLP-1 agonists (like Novo's semaglutide which we will review later) helps by slowing digestion, which prevents blood sugar spikes and reduces the demand for insulin. GLP-1 also cuts inflammation and eases cell stress, making cells more responsive to insulin. It also suppresses glucagon secretion from alpha cells, which curbs excess glucose in the blood. As you might have understood, the result is much lower stress on the pancreas and much better glucose regulation inside the body, which is a perfect outcome for diabete type 2 patients.
You might see now why GLP-1 drugs are not just a band-aid solution: by lowering the stress on the pancreas and improving the cells' resistance to insulin, these address the deeper causes of diabete type 2.
Another benefit is that doctors noticed that patients on these drugs lost weight. By slowing digestion, GLP-1 signals a feeling of fullness to the brain, which makes people want to eat less. Ironically, by helping patients loose weight, GLP-1 drugs solve for obesity: one major aggravating factor for diabete type 2!
The market opportunity for GLP-1 drugs
Over 1 billion people worldwide grapple with obesity, a number climbing due to poor diets and too little exercise. Obesity is also placing a heavy burden on already-stretched healthcare systems as it is the root cause of many chronic conditions (diabete, cardiovascular issues, sleep apnea, renal dysfunction), a strong incentive for them to tackle this issue. Currently, 2% of the 1bn people living with obesity are receive treatment. As a results, analysts estimate the obesity drug market by 2035 at 150 bnUSD (versus 10 bnUSD in 2023). A huge growth moving forward!
Regarding diabete, about 589 million adults are currently living with diabete, projected to grow at 850m by 2050. However, the diabete market is already more established, accounting for two-thirds of Novo sales in 2025. Growth will therefore remain significant but slower than for obesity (because it is starting from a higher base, and ultimately reaching less people worldwide).
Effectiveness and side effects of Novo Nordisk products versus Eli Lilly
Currently, the diabete and obesity market is a duopoly between Novo Nordisk and Eli Lilly. Let's deep dive on the effectiveness of their drugs with a focus on weight loss metrics, given obesity is the largest growth market.
For injectables, Novo sells Semaglutide under the brand name Wegovy while Eli sells Tirzepatide under the Zepbound brand.
The Surmount-5 study showed Semaglutide 2.4mg (injectable) results in a mean weight loss of 13.7%, versus 20.2% for Tirzepatide 15 mg after 72 weeks. The side effects are similar across both drugs. In short, for injectables, Tirzepatide has a much better effectiveness with similar side effects.
For the oral daily format, the Novo 25mg semaglutide tablet have the same effectiveness as the injection (13.6% weight loss under the Oasis 4 study). In addition, Novo is offering the 50mg semaglutide tablet which shows a 17.4% weight loss reduction after 68 weeks (Oasis 1 trial). In comparison, the Phase 3 Attain-1 trial reached 12.4% weight loss for Orforglipron (Eli Lilly's version for oral) after 72 weeks. Both Eli Lilly and Novo products have similar side effects. However, Orforglipron offers slightly better convenience (Novo's pill should be taken on an empty stomach and wait 30 minutes before eating, while Eli's product can be taken at any moment of the day).
In short, for oral, Semaglutide has a better effectiveness while being slightly less convenient.
Pipeline of Novo Nordisk and Eli Lilly
The pipeline of Novo Nordisk through 2026 and 2027 is mainly focused on higher doses versions of existing drugs and new next-generation molecules, centered around semaglutide:![]()
- Cagrisema 2.4mg shows 23% weight loss after 84 weeks (versus 25.5% for Eli Lilly Zepbound) as part of Redefine 4 trial. Novo plans to start a Phase 3 trial in the second half of 2026 with a higher dose of semaglutide (7.2mg)
- Wegovy high dose (7.2mg) : this is already approved in Europe, and management expects an FDA decision by end of Q1 2026, which has shown 21% weight loss
- Zenagamtide (formerly amycretin) is another next-generation GLP-1/amylin co-agonist that showed 24% weight loss in 36 weeks during Phase 2 trial. Novo is starting the Amaze phase 3 program in early 2026, with an expected launch before 2030
- Finally Novo has said that two triple agonist molecules are advanced through clinical trials with potential for higher weight loss, but didn't give details about dates / timelines
In comparison, Eli Lilly triple agonist (Retatrutide) is showing 24% weight loss in Phase 2 trial after 48 weeks, with a launch expected in 2027/2028
Based on this, Eli Lilly will most likely keep the lead on the effectiveness of injectables, especially given that Retatrutide is arriving in 2027/2028 and that Zenagamtide is not coming before 2030
Personal conviction
My personal conviction is that for slightly overweight people, they will prefer the convenience of the oral pill in daily format and Novo Nordisk has a clear lead there (especially with the 50mg format). These slightly overweight people (BMI between 25 and 30) account for 30-35% of adults in the US. For obese people (BMI above 30) for which loosing weight is a deep trauma, they will prefer maximizing weight loss using a weekly injectable and avoid the bariatric surgery. Here, Eli Lilly has an undisputed lead with Tirzepatide. These obese people account for 40-43% of adults in the US.
Based on this, I would assume that Eli Lilly can capture about 60% of the obesity market in the next 3 years, versus 40% of the Novo Nordisk market (assuming similar pricing levels). I don't think a winner-take-all is realistic given the product considerations, especially if you include other considerations such as manufacturing capacity, commercial / distribution capabilities of these two giants.
Beyond the next 3 years, we need to start looking at the pipeline of the rest of pharma companies who aren't planning to sit tight and watch the duopoly race!
For the oral daily format, the Novo 25mg semaglutide tablet have the same effectiveness as the injection (13.6% weight loss under the Oasis 4 study). In addition, Novo is offering the 50mg semaglutide tablet which shows a 17.4% weight loss reduction after 68 weeks (Oasis 1 trial). In comparison, the Phase 3 Attain-1 trial reached 12.4% weight loss for Orforglipron (Eli Lilly's version for oral) after 72 weeks. Both Eli Lilly and Novo products have similar side effects. However, Orforglipron offers slightly better convenience (Novo's pill should be taken on an empty stomach and wait 30 minutes before eating, while Eli's product can be taken at any moment of the day).
In short, for oral, Semaglutide has a better effectiveness while being slightly less convenient.
Pipeline of Novo Nordisk and Eli Lilly
The pipeline of Novo Nordisk through 2026 and 2027 is mainly focused on higher doses versions of existing drugs and new next-generation molecules, centered around semaglutide:
- Cagrisema 2.4mg shows 23% weight loss after 84 weeks (versus 25.5% for Eli Lilly Zepbound) as part of Redefine 4 trial. Novo plans to start a Phase 3 trial in the second half of 2026 with a higher dose of semaglutide (7.2mg)
- Wegovy high dose (7.2mg) : this is already approved in Europe, and management expects an FDA decision by end of Q1 2026, which has shown 21% weight loss
- Zenagamtide (formerly amycretin) is another next-generation GLP-1/amylin co-agonist that showed 24% weight loss in 36 weeks during Phase 2 trial. Novo is starting the Amaze phase 3 program in early 2026, with an expected launch before 2030
- Finally Novo has said that two triple agonist molecules are advanced through clinical trials with potential for higher weight loss, but didn't give details about dates / timelines
In comparison, Eli Lilly triple agonist (Retatrutide) is showing 24% weight loss in Phase 2 trial after 48 weeks, with a launch expected in 2027/2028
Based on this, Eli Lilly will most likely keep the lead on the effectiveness of injectables, especially given that Retatrutide is arriving in 2027/2028 and that Zenagamtide is not coming before 2030
Personal conviction
My personal conviction is that for slightly overweight people, they will prefer the convenience of the oral pill in daily format and Novo Nordisk has a clear lead there (especially with the 50mg format). These slightly overweight people (BMI between 25 and 30) account for 30-35% of adults in the US. For obese people (BMI above 30) for which loosing weight is a deep trauma, they will prefer maximizing weight loss using a weekly injectable and avoid the bariatric surgery. Here, Eli Lilly has an undisputed lead with Tirzepatide. These obese people account for 40-43% of adults in the US.
Based on this, I would assume that Eli Lilly can capture about 60% of the obesity market in the next 3 years, versus 40% of the Novo Nordisk market (assuming similar pricing levels). I don't think a winner-take-all is realistic given the product considerations, especially if you include other considerations such as manufacturing capacity, commercial / distribution capabilities of these two giants.
Beyond the next 3 years, we need to start looking at the pipeline of the rest of pharma companies who aren't planning to sit tight and watch the duopoly race!
Where do other pharma companies stand in the race
Overall, Roche's drug CT-388 seems the most promising candidate with 22.5% weight loss after 48 weeks, which should hit the market around 2029/2030. This will coincide with the launch date of Zenagamtide from Novo and Retatrutide from Eli Lilly which are slightly better, both standing at 24%.
Based on product considerations alone, and setting alone other variables (pricing strategy, manufacturing capacity, commercial excellence), I think that Novo is a serious contender to retain a solid share of the obesity drug market, probably in the 30-40% range for the longer-term