A nasal spray for semaglutide? Not yet

A team based at Macquarie University and the Woolcock Institute of Medical Research in Sydney has built a nasal-spray version of semaglutide and tested it in the lab and in animals, not in people. Published online on 30 August 2026 in the International Journal of Pharmaceutics, the study reports a nanoparticle carrier that packaged 89% of the drug and measured about 26 nanometres across^[1]. It is early-stage formulation research, not a new way to take the drug.

Why researchers are trying to avoid the needle

Every approved form of semaglutide today reaches the body one of two ways: a once-weekly subcutaneous injection (Ozempic, Wegovy) or a once-daily oral tablet (Rybelsus). The EMA's authorisation for Ozempic describes prefilled pens for self-injection into the belly, thigh or upper arm^[2]. The researchers behind the new study point to the trade-off in each route: injections work well but are invasive and some patients find them hard to keep up with, while the oral tablet loses much of its potency to the digestive system before it reaches the bloodstream, a problem known as the first-pass effect. A nasal route, delivered through the nose without a needle, is the alternative they set out to test.

Semaglutide is a peptide, a short chain of amino acids, and peptides are generally fragile in the gut and in the bloodstream. That fragility is part of why the injectable and oral semaglutide brands needed years of formulation engineering before they reached patients at all: the oral tablet Rybelsus relies on an absorption enhancer just to survive the stomach in useful amounts. A nasal route sidesteps the stomach entirely by crossing the nasal mucosa directly, which is the same basic idea behind existing nasal sprays for other peptide and protein drugs already on the market. Whether it works well enough, and safely enough, for semaglutide specifically is exactly what this study was designed to start answering.

What the nanocarrier is made of, and how it was tested

The carrier is built from a synthetic, biocompatible polymer the researchers call PNPHO, engineered to respond to temperature and to stick to the mucus lining of the nasal cavity for longer than the free drug would on its own. Semaglutide was loaded into nanoparticles made from this polymer, then tested for particle size, stability, how well they adhered to nasal tissue, where they settled inside a model of the human nasal cavity built for spray-deposition testing, how the drug released over time, and how well it crossed a layer of nasal epithelial cells grown in the lab. That in vitro battery of tests came before any animal work, which is the standard order for formulation research: prove the carrier behaves as intended on the bench before testing it in a living system.

What the researchers found

The nanoparticles measured 26.14 nanometres on average, carried a negative surface charge, and held onto 89% of the loaded semaglutide. Against enzymes that would normally break the peptide down, the nanoparticle version held up better than free semaglutide. In cell culture, more of the drug crossed the nasal epithelial cell layer when packaged in the nanoparticle than when given alone. In a separate cell model of the blood-brain barrier, the nanoparticle version crossed less, which the researchers frame as a possible safety feature rather than a drawback, since semaglutide's intended targets are appetite-control regions rather than the wider brain.

In live animals, the nanoparticle formulation stayed in the nasal sinus region longer than expected and produced improved glucose tolerance on a once-daily dosing schedule, which the researchers read as evidence of an extended period of drug activity. No fluorescent tracer from the formulation was detected in the brain during these tests. The researchers describe the combined results as evidence that a needle-free nasal route for semaglutide is worth pursuing further with additional animal safety work.

What this is not

This is not a clinical trial, not a product, and not something a patient can ask a pharmacy for. The work described here is in vitro cell testing and animal experiments, not a study in humans. No dosing, safety, or efficacy data in people exist for this formulation. The only semaglutide products authorised by the EMA, the MHRA and the FDA remain the injectable Ozempic and Wegovy pens (the weight-management brand carries its own separate EMA authorisation^[3]) and the oral Rybelsus tablet. Moving a laboratory formulation from a nanoparticle bench study to an approved medicine typically takes years of further animal safety work followed by phase 1, 2 and 3 human trials and full regulatory review, and most preclinical delivery formulations never complete that path.

The study also has limits worth naming plainly. It is a single formulation-development paper from one laboratory group, not yet replicated elsewhere. It reports glucose-tolerance and biodistribution data from animal experiments, not weight-loss or HbA1c outcomes, so it says nothing yet about whether a nasal version would match the effectiveness of the injectable or oral products people actually take today. And reduced blood-brain-barrier crossing in a cell model is a reassuring early signal, not proof of a comparable long-term safety profile in humans.

Where this fits for readers

If you take semaglutide today, or are considering it, this research changes nothing about how the drug is prescribed or administered right now. It is a signal of where the field is headed, not a new option to discuss at your next appointment. For the current, approved routes of administration and country-specific access details, see our semaglutide page. Questions about switching formulations, starting, or stopping treatment belong with a prescribing clinician who knows your history, not with a preclinical paper.