Three kinds of rash, three different rows
At the injection site: the US label reports injection site reactions, giving rash and redness as examples, in about 2% of adults in its 26-week trials, with fewer than 0.2% stopping treatment. [1] Europe calls them usually mild. [2] The EU leaflet lists bruising, pain, irritation, itching and rash at the site. [2]
Elsewhere on the body: Europe places rash in its common class and hives and itching in the uncommon class. [2] The US label lists itching only among postmarketing reports. [1]
As part of an allergic reaction: the US label describes postmarketing reports of anaphylaxis and angioedema (deep swelling of the face, lips, tongue or throat) and says Victoza® should be stopped if this happens. [1] Europe reports angioedema in 0.05% of trial patients. [2]
| Trial and term | Victoza® | Comparison |
|---|---|---|
| LEAD-2, 26 weeks, with metformin: rash [3] | 0.6 mg 0.0%; 1.2 mg 0.4%; 1.8 mg 0.4% | Placebo 0.8%; glimepiride 1.2% |
| LEAD-2: pruritus [3] | 0.6 mg 0.8%; 1.2 mg 1.3%; 1.8 mg 0.4% | Placebo 0.0%; glimepiride 1.2% |
| LEAD-5, 26 weeks, with metformin and glimepiride: rash [3] | 1.8 mg 1.3% | Placebo 0.0%; insulin glargine 0.9% |
| Trial 1860, 26 weeks, with metformin: rash [3] | 1.2 mg 1.8%; 1.8 mg 1.4% | Sitagliptin 0.9% |
| Trial 1842, 52 weeks, 1.8 mg with metformin: rash; pruritus [3] | 1.9%; 2.5% | No placebo arm |
| LEAD-3, 52 weeks: all skin disorders [3] | 1.2 mg 9.2%; 1.8 mg 9.8% | Glimepiride 6.9% |
| US immunogenicity pool: hives, angioedema and similar [1] | 0.8% | Comparators 0.4% |
Antibodies and allergy-type events
In five US adult trials, 9% of the people tested developed antibodies to liraglutide, and 1% had antibodies that neutralised it in a laboratory test. [1] Allergy-type events, such as hives and angioedema, occurred in 0.8% of people on Victoza® and 0.4% on comparators, with hives making up about half of the Victoza® cases. [1] People with antibodies were not more likely to have these events than people without them. [1]
This matters for the question many people ask: whether a rash means you are “allergic to Victoza®”. Most skin events in the trials were small and not clearly linked to the drug, but a true allergic reaction is listed and is a reason to stop. [1] The US label also asks for caution in anyone who has had anaphylaxis or angioedema with another GLP-1 medicine. [1]
Lumps where you inject: cutaneous amyloidosis
Because Victoza® is injected every day, the same patches of skin are used often. The US label asks you to rotate injection sites within the same body region to reduce the risk of cutaneous amyloidosis, a build-up of protein under the skin reported after approval. [1] Canada’s leaflet explains that Victoza® may not work as well if injected into a lumpy area and says to change the site with each injection. [3] Europe lists cutaneous amyloidosis with unknown frequency. [2]
These lumps are not a rash, but people often notice them at the same time as redness or bruising at the site. The page on Victoza® and injection site reactions covers bruising and redness in more detail.
Research beyond the label
A 2026 analysis of US FDA adverse event reports from 2018 to 2024 looked at rash, itching, hives, hair loss and angioedema across four GLP-1 medicines. [4] Skin reports were proportionally less common with GLP-1 medicines than with DPP-4 inhibitors, another diabetes drug class, and liraglutide had lower odds of a skin report than dulaglutide, while exenatide had higher odds. [4] Voluntary reports reflect what people choose to report, so they cannot give rates or prove cause.
Other common causes of a rash
MedlinePlus lists contact dermatitis from soaps, cosmetics, detergents, clothing dyes and rubber or latex as a frequent cause, along with eczema, psoriasis, seborrhoeic dermatitis, shingles, insect bites, infections and other medicines. [5] MedlinePlus describes hives as red, sometimes itchy bumps, usually from an allergic reaction to a drug or food, and notes infections and stress as other causes. [6]
Two practical points for Victoza® users: the alcohol swab, adhesive plasters and a new soap can all irritate the injection area, and people with diabetes often take several medicines, any of which could be behind a new rash. The Victoza® Medication Guide lists the inactive ingredients as disodium phosphate dihydrate, propylene glycol, phenol and water for injection. [1]
What the sources describe
- Wash with gentle cleansers in warm, not hot, water and pat dry; avoid scrubbing. [5]
- Stop any recently added cosmetics or lotions and leave the area exposed to air when possible. [5]
- Over-the-counter 1% hydrocortisone cream and oral antihistamines are options MedlinePlus mentions; ask your pharmacist which suits you. [5]
- Rotate injection sites within a region and avoid injecting into lumpy skin. [1][3]
- Do not stop or change a medicine without talking to your provider, unless you have signs of a serious allergic reaction. [1][5]
Victoza® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk A/S.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| Rash or itching with swelling of the face, lips, tongue or throat, breathing or swallowing problems, fainting or a very rapid heartbeat | Stop Victoza® and call emergency services | Emergency | Medication Guide [1]; MedlinePlus [7] |
| Shortness of breath, a tight throat or a swollen face with a rash | Emergency services (911 or local number) | Emergency | MedlinePlus [5] |
| Rash with joint pain, fever or sore throat, or red streaks, swelling and tenderness that suggest infection | Contact your provider | Today | MedlinePlus [5] |
| New rash, hives or itching after starting Victoza® | Call your doctor straight away; MedlinePlus lists this among reasons to stop liraglutide | Today | MedlinePlus liraglutide [8] |
| Injection site rash or redness that is severe or does not go away | Tell your doctor | At your next appointment | MedlinePlus liraglutide [8] |
| Lumps under the skin at injection sites | Show your prescriber or diabetes nurse | At your next appointment | Canadian Patient Medication Information [3] |
