How often dizziness was reported
All three US injection safety tables include a dizziness row; for the 7.2 mg trials, a footnote says it also covers postural dizziness, the light-headed feeling on standing up. [1] The EU product information and the Canadian monograph add their own pools. [2][3]
| Source and population | Placebo | Wegovy® 2.4 mg | Wegovy® 7.2 mg |
|---|---|---|---|
| US Table 3: adults, 2.4 mg weight-reduction pool [1] | 4% | 8% | — |
| US Table 4: adults, 7.2 mg trials (incl. postural) [1] | 1% | 5% | 6% |
| US Table 5: adolescents 12 and older [1] | 3% | 8% | — |
| Canadian Table 4: adults, STEP 1–3 [3] | 3.8% | 7.7% | — |
| EU SmPC 4.8: STEP 1–4 [2] | not given | “common”, mainly during dose escalation | — |
Reading the pools
In every pool, dizziness was more frequent on Wegovy® than on placebo. The adult 2.4 mg pool and the adolescent trial both landed at 8% on the medicine. In the 7.2 mg trials the placebo rate was low (1%), so even small figures on the medicine show a clear difference, while the step from 2.4 mg to 7.2 mg was a single percentage point. [1] Novo Nordisk’s patient page lists dizziness among the most common side effects. [4]
The US label does not tie dizziness to a particular week, but the EU product information places it mainly in the dose-escalation period, [2] the same weeks in which digestive reactions cluster. [1] The injection is built up from 0.25 mg in four-week steps, and a prescriber may hold a step for four weeks if a dose is not tolerated. [1]
Low blood pressure, fainting and fluids
Section 6.1 reports reactions related to low blood pressure, namely hypotension, orthostatic hypotension (a drop on standing) and decreased blood pressure, in 1.3% of adults on Wegovy® and 0.4% on placebo, and fainting (syncope) in 0.8% versus 0.2%. Some were related to digestive reactions and the fluid loss that can come with them, and low blood pressure was seen more often in people also taking medicines for high blood pressure. In the adolescent trial, hypotension was reported in 2.3% of teenagers on Wegovy® and none on placebo. [1]
The EU table places hypotension and orthostatic hypotension in its “uncommon” band, [2] and the Canadian monograph lists fainting among reactions under 1%. [3] Section 5.5 of the US label connects the same fluid loss to a kidney warning. [1] MedlinePlus lists dizziness or light-headedness among signs of severe dehydration. [6]
Light-headedness, blood sugar and allergy
The Medication Guide puts dizziness or light-headedness first in its list of possible low blood sugar signs. The warning applies to people with type 2 diabetes, especially those also taking insulin or a sulfonylurea. In a Wegovy® trial of adults with type 2 diabetes, readings under 54 mg/dL occurred in 6.2% on the injection and 2.5% on placebo, and section 7.1 lets the prescriber lower the insulin or sulfonylurea dose when Wegovy® is started. [1] The Canadian leaflet notes that low blood sugar may reduce concentration or cause dizziness, and advises against driving or using machines if that happens. [3]
Feeling dizzy or fainting also appears in the Medication Guide’s list of serious allergic reaction signs, together with swelling of the face, lips, tongue or throat and trouble breathing or swallowing. [1]
What a health-records study found
A 2025 US study of electronic health records compared adults prescribed semaglutide (419,497 people) or tirzepatide with matched controls and looked for new diagnoses of vestibular (inner-ear balance) disorders. Semaglutide users had a higher cumulative incidence, rising from 0.12% at 6 months to 0.41% at 3 years, against 0.03% to 0.16% in controls. [7] The absolute numbers were small, the study was observational and could not separate the medicine from other differences between groups, and it did not report the Wegovy® dose. It raises a question rather than settling one.
Other causes, and what helps on standing
MedlinePlus says most dizziness is not serious and settles on its own or is easy to treat. Light-headedness happens when the brain briefly gets too little blood: a sudden drop in blood pressure, dehydration from vomiting, diarrhoea or fever, getting up too quickly, flu, colds, allergies, low blood sugar or medicines that lower blood pressure. A spinning feeling (vertigo) more often comes from the inner ear, such as benign positional vertigo, labyrinthitis or Ménière disease. Less often, heart rhythm problems, stroke or internal bleeding are responsible. [5]
For light-headedness on standing, MedlinePlus suggests avoiding sudden changes in posture, getting up slowly and sitting for a few moments first, and holding on to something when you stand. For vertigo, it suggests keeping still during an attack and avoiding driving or climbing until symptoms have cleared. [5] The Wegovy® Medication Guide stresses drinking enough fluids to reduce the chance of dehydration. [1]
Wegovy® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.
When to get help
The signs and contact information below come from this article’s sourced guidance.
Emergency
- Fainting, or dizziness with swelling of the face or throat or difficulty breathing
Contact: Stop Wegovy® and get emergency help
Medication Guide [1]
- Dizziness with chest pain, an irregular or racing heartbeat, weakness, an arm or leg you cannot move, or a change in speech or vision
Contact: Emergency number or emergency room
MedlinePlus [5]
- Dizziness with sweating, shakiness, confusion or hunger, if you have diabetes
Contact: Treat as low blood sugar per your diabetes plan; emergency help if severe