This article was inspired by Phil Finish and his original piece, “GLP-1s Follow Insulin Down the Cost Curve.” It expands on the idea with additional background on fermentation, manufacturing capacity and endotoxin control.
TL;DR
Semaglutide already uses fermentation. Novo Nordisk’s established process uses engineered yeast to produce a precursor, which is then purified and chemically modified.
Engineered E. coli can also make a semaglutide intermediate. Virtu did not invent that concept; its claim is that it can make the process more productive at industrial scale.
If Virtu’s platform works as claimed, it could expand supplies of the active ingredient. Its performance figures are company-reported, and any bacterial process must include stringent endotoxin control.
The enormous demand for Ozempic, Wegovy and other GLP-1 medicines has made manufacturing almost as important as drug discovery. Finding an effective medicine is only the beginning. Manufacturers must also produce enough active pharmaceutical ingredient, or API, purify it to pharmaceutical standards and turn it into finished pens or vials.
As more GLP-1 products enter different markets, dependable sources of qualified API could become an important constraint. Chinese biotechnology company Virtu Pharmako says its fermentation platform could help expand that supply.
Semaglutide already uses fermentation
Semaglutide is a peptide made from a chain of 31 amino acids. Many therapeutic peptides are produced through solid-phase peptide synthesis, or SPPS, in which amino acids are added one at a time. The method is precise and well established, but longer chains require repeated chemical reactions, washing and purification.
The established semaglutide process already uses a different approach. The European Medicines Agency describes the reference product as being produced using recombinant DNA technology in the yeast Saccharomyces cerevisiae, followed by purification and chemical modification.
In simple terms, engineered yeast cells make a semaglutide precursor. The material is then recovered and purified before chemistry adds the specialised side chain that helps the medicine remain active for about a week. Semaglutide is therefore already made through a combination of fermentation and chemistry.
Where E. coli enters the story
Yeast is not the only organism that can be programmed to make peptide material. Scientists can also insert genetic instructions into E. coli, allowing the bacteria to produce a semaglutide precursor as they grow in a fermentation vessel.
A peer-reviewed study published in 2026 demonstrated one version of this idea. The researchers engineered E. coli to make a larger fusion protein containing several copies of a semaglutide intermediate. They recovered that material, cut the individual peptide sections free and purified them. After cleavage and purification, the study reported the P29 intermediate at 98% purity, with a yield of 5.85 grams per litre of fermentation broth.
This wasn’t finished semaglutide because the long-acting fatty side chain had not yet been attached. It was also an independent research process, not Virtu’s method. What it established was that engineered E. coli can produce a useful semaglutide intermediate at gram-per-litre levels.
What Virtu says is different
Virtu is not claiming to have invented the basic idea of using engineered E. coli. Its proposition is that it can make the process work more efficiently at industrial scale. The company describes a proprietary platform combining high-cell-density fermentation with downstream recovery and purification. In a 2024 announcement, a Virtu co-founder said its fermentation process could reach an OD600 reading above 250, a measure used to estimate the concentration of cells in the broth. The company also claimed that, in an insulin-production example, a fermenter of the same size could produce three to four times the average output.
Those figures were reported by Virtu and haven’t been independently demonstrated for commercial semaglutide production and the insulin comparison shouldn’t be treated as a measured semaglutide result. Virtu has also not publicly disclosed enough detail about its semaglutide construct, cleavage process or final recovery yield to compare its method directly with the published 2026 process.
The safest description is that Virtu says it has developed a more productive industrial version of an existing concept. Its claimed advantage lies in growing more cells in each vessel and efficiently recovering useful product from them, not in discovering that E. coli can make a semaglutide intermediate.
What about endotoxin?
Using E. coli creates an additional manufacturing challenge because the bacterium’s outer membrane contains endotoxin. When the cells are broken open to recover the peptide, endotoxin can enter the process stream. That doesn’t automatically make an E. coli-derived medicine unsafe. Many established medicines are produced using bacterial fermentation. Manufacturers must show that their complete process controls and removes endotoxin to validated limits through prevention, purification and finished-product testing. It’s a familiar requirement, but it’s a demanding one.
Why this could matter
The potential bottleneck isn’t simply the amount of peptide powder available. Manufacturers need correctly made, highly purified and thoroughly tested API from qualified facilities, as well as enough capacity to fill it into pens or vials. If Virtu can reproduce its claimed performance at commercial scale, its platform could add another source of semaglutide API and make the supply chain more resilient. Higher output from each fermenter could also reduce direct manufacturing costs.
For now, the important development isn’t a completely new way of making semaglutide. It’s the possibility that an existing E. coli approach can be industrialised more efficiently. Whether Virtu can consistently deliver purified, endotoxin-controlled and regulatory-compliant material at scale is the question that will decide how important its technology becomes.
Sources
Virtu Pharmako/36Kr financing and manufacturing announcement, 30 October 2024
Virtu Pharmako: technology features and claimed advantages
2026 PLOS One study of recombinant semaglutide-intermediate production in E. coli
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