New study links GLP-1 drugs to smell and taste loss: what Canadian weight-loss patients should know

This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

A study of nearly 900,000 people with Type 2 diabetes, published June 26, 2026 in JAMA Otolaryngology Head and Neck Surgery, found that patients who used GLP-1 receptor agonist drugs long-term had an 81% higher relative risk of developing smell disturbances and a 52% higher relative risk of taste disturbances compared to patients on other diabetes medications. The study drew on electronic health records collected between 2017 and 2026, with roughly half of participants using GLP-1 drugs. For Canadians currently taking semaglutide (sold in Canada as Ozempic for diabetes and Wegovy for weight management) or other Health Canada-approved GLP-1 therapies, this finding adds a new side-effect consideration to discuss with a prescribing physician or pharmacist.

The research was conducted by Jonathan Zontag and Nir Zontag at Hebrew University in Jerusalem and reported by Reuters. The study cohort was large enough to detect a statistically meaningful signal, but the actual event rates were quite small: 0.37% of GLP-1 users developed a smell or taste disturbance, compared to 0.22% of the control group. That gap is real, but it means the large majority of patients on these drugs did not experience either problem during the two-year follow-up period.

What this means in Canada

Health Canada has approved several GLP-1 receptor agonists. Semaglutide is available as Ozempic (approved for Type 2 diabetes) and Wegovy (approved for chronic weight management in adults with obesity or overweight plus a weight-related condition). Liraglutide is available as Victoza (diabetes) and Saxenda (weight management). Dulaglutide is sold as Trulicity. None of these products currently list smell or taste disturbance as a labelled adverse effect in their Health Canada product monographs, though nausea, vomiting, and other gastrointestinal effects are well-documented.

Health Canada has not issued updated guidance in response to this study as of June 27, 2026. The SOGC (Society of Obstetricians and Gynaecologists of Canada) has not issued a position statement on GLP-1 sensory side effects, and the SOGC's primary GLP-1 guidance to date has focused on reproductive health considerations.

On the coverage side, provincial pharmacare programs vary considerably. In Ontario, Ozempic is listed on the Ontario Drug Benefit (ODB) formulary for Type 2 diabetes with specific eligibility criteria; Wegovy is not currently listed on ODB. In Quebec, the RAMQ covers some GLP-1 agents for diabetes indications but coverage for obesity indications remains limited. British Columbia's PharmaCare and Alberta's AHCIP similarly cover GLP-1 drugs primarily for diabetes, with weight-management indications subject to exception drug status processes. Patients paying out of pocket for Wegovy in Canada face costs that can exceed CAD $400 per month.

Canadian telehealth platforms including Felix (a Canadian online pharmacy and prescribing platform), Cleo (a Canadian women's health platform), and Science & Humans (scienceandhumans.com), a Canadian hormone and metabolic health service, have all expanded GLP-1 prescribing in recent years. US-only platforms such as Hone Health and Midi do not serve Canadian patients.

What changed

Prior to this study, the known side-effect profile of GLP-1 drugs was dominated by gastrointestinal symptoms: nausea, vomiting, diarrhea, and constipation. Pancreatitis and thyroid concerns have also been studied. Sensory effects on smell and taste had not been systematically examined in a cohort of this size.

The JAMA Otolaryngology editorial published alongside the study put the finding in a broader context. Smell dysfunction is one of the more reliable early markers of neurodegenerative conditions, including Parkinson's disease and Alzheimer's disease. The editorial noted that GLP-1 receptors are present in the brain and olfactory system, which gives the association a plausible biological basis, though the mechanism has not been confirmed. The editorial also raised a values question: for patients managing serious conditions like uncontrolled diabetes or cardiovascular disease, a small increase in sensory disturbance risk may be acceptable. For patients using GLP-1 drugs primarily for modest weight loss without a significant metabolic indication, the calculus may differ.

This is an observational study based on health records, not a randomized controlled trial. That distinction matters: patients who use GLP-1 drugs may differ from those who do not in ways the researchers could not fully account for, which means the association does not confirm that the drugs directly cause smell or taste changes.

What Canadian patients should know

If you are currently taking a GLP-1 drug and notice changes in your sense of smell or taste, report it to your prescriber. In Canada, patients and healthcare providers can also report suspected adverse drug reactions directly to Health Canada through the Canada Vigilance Program. This kind of real-world reporting is how post-market safety signals get tracked.

The absolute numbers from this study are worth keeping in mind. Roughly 1 in 270 GLP-1 users in the study developed a smell or taste disturbance over two years, compared to roughly 1 in 455 in the control group. That is a meaningful relative difference, but it is not a common outcome.

Patients who are prescribed GLP-1 drugs for well-established indications (Type 2 diabetes with cardiovascular risk, or obesity with comorbidities) should not stop medication based on this study alone. Any decision to change or discontinue a GLP-1 therapy should involve a conversation with a physician or nurse practitioner who knows the full clinical picture.

For patients who are considering starting a GLP-1 drug through a telehealth service, this study is a reasonable item to raise during the intake or prescribing consultation. Platforms operating in Canada are required to follow Health Canada-approved prescribing information, but the informed consent conversation can and should include emerging safety data.

Provincial differences in coverage mean that some patients are paying significant out-of-pocket costs for these medications. If a sensory side effect does emerge, that cost-benefit calculation becomes more personal.

Limitations and open questions

The study does not establish causation. It cannot rule out that patients on GLP-1 drugs differed from controls in unmeasured ways, including diet changes, concurrent medications, or the severity of their underlying diabetes.

The study population had Type 2 diabetes. Whether the same risk pattern applies to people using GLP-1 drugs solely for weight management, who may be younger and metabolically different, is not known.

The biological mechanism is unconfirmed. GLP-1 receptors exist in olfactory and gustatory pathways, but whether the drugs act on those receptors in a clinically meaningful way has not been demonstrated in human trials.

Health Canada has not yet issued guidance on this finding, and no Canadian clinical society has published a formal response. The SOGC (Society of Obstetricians and Gynaecologists of Canada) and the Canadian Diabetes Association (Diabetes Canada) have not updated their GLP-1 guidance to address sensory side effects as of the publication date of this article.

Longer follow-up data are needed. The study covered two years. Whether sensory disturbances resolve after stopping the drug, progress over time, or remain stable is not addressed.

This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

Editorial note

Hormone Journal articles are written by our editorial team and reviewed against published clinical guidelines, with a focus on Canadian patient access. We do not promote specific clinics or providers.