What each document reports
The US label lists headache in its adult table of reactions reported by at least 2% of people and more often than on placebo; Canada gives the same counts from the same five trials. [1][3] After approval, headache was also reported spontaneously with liraglutide, under neurological effects. [1]
| Document and group | Saxenda® | Placebo | Note |
|---|---|---|---|
| US label, Table 2, adults [1] | 13.6% | 12.6% | Gap of one percentage point |
| Canadian monograph, Table 3, adults [3] | 461 of 3,384 (13.6%) | 244 of 1,941 (12.6%) | Same adult pool |
| US label, Table 3, ages 12–17 [1] | Not listed | — | Table threshold 3% and above placebo |
| EU SmPC, Table 4 [2] | Very common (≥1 in 10) | — | Leaflet: usually goes away in days or weeks |
| US label, section 6.2 [1] | Reported after approval | — | No rate; cause not established |
Why “very common” and “one point above placebo” are both true
The EU frequency classes describe how often something happened in people taking the medicine. Headache affected more than one in ten adults on Saxenda®, so it is very common by that rule. [2] The US and Canadian tables instead put the two groups side by side, and there headache stands out mainly because so many people on placebo had it too. [1][3]
Put simply, about one extra adult in every hundred reported headache on Saxenda®. [1] Most headaches during the trials would probably have happened anyway, from the same everyday causes as in the placebo group. That is useful when you are deciding whether a headache is worth tying to the medicine, though the comparison cannot tell you about any single headache.
Unlike dizziness and fatigue, headache is not named in the label’s note about effects concentrated in the first 12 weeks. [1] The EU and Canadian leaflets nonetheless expect it to pass within days or weeks. [2][3]
Label effects that can set off a headache
- Dehydration. Nausea, vomiting and diarrhoea can leave you short of fluid, and MedlinePlus lists headache among signs of mild to moderate dehydration. The Saxenda® label links fluid loss to kidney injury. [1][5]
- Low blood sugar. Headache appears in the Medication Guide’s list of warning signs, together with shakiness, sweating, hunger and confusion. The risk is highest for adults with type 2 diabetes on insulin or a sulfonylurea and for teenagers on Saxenda®. [1][6]
- Poor sleep. Insomnia was listed in 2.4% of adults against 1.7% on placebo, mainly in the first three months, and lack of sleep is a known migraine trigger. [1][2][4]
Causes unrelated to Saxenda®
Tension headache is the most common type, linked to tight neck, shoulder and jaw muscles and to stress or anxiety. Migraine causes throbbing, often one-sided pain and can be triggered by caffeine withdrawal, lack of sleep, alcohol and certain foods. Colds, flu, fever, sinus swelling and premenstrual changes can all cause headaches too. [4]
MedlinePlus also describes rebound or medicine-overuse headaches, which can develop in people taking pain medicines more than three days a week. [4] That is worth knowing if headaches have led you to take pain relievers most days during the first weeks of Saxenda®.
Cutting back on coffee or tea while eating less, or drinking less because of nausea, can each play a part. [4][5] Rare serious causes include very high blood pressure, infection of the brain, bleeding in the brain and sleep apnoea. [4]
Easing a headache, and pain relievers
MedlinePlus suggests treating headaches early: drink water to avoid dehydration, especially if you have vomited, rest in a quiet, dark room, put a cool cloth on your head and use relaxation techniques. A headache diary recording timing, food, drink, sleep and activity can reveal triggers to discuss with your provider. [4]
For tension headaches, MedlinePlus mentions acetaminophen, aspirin or ibuprofen, and asks you to talk to your provider if you need pain medicines three or more days a week. [4] On liraglutide specifically, an interaction study found that it lowered the peak blood level of a single acetaminophen dose by 31% and delayed it by up to 15 minutes, without changing total exposure; the EU summary says no dose adjustment of paracetamol is needed. [1][2]
If you are dehydrated from vomiting or diarrhoea, check with a pharmacist before using ibuprofen or similar medicines: MedlinePlus lists these anti-inflammatory drugs among medicines that can injure the kidneys, and the Saxenda® label already links dehydration to kidney injury. [1][7]
Saxenda® is a registered trademark of Novo Nordisk A/S. PepLabo is not affiliated with or endorsed by Novo Nordisk.
When to get help
| Sign | Who to contact | How fast | Source |
|---|---|---|---|
| A sudden, explosive or “worst ever” headache | Emergency number or nearest emergency room | Emergency | MedlinePlus [4] |
| Headache with slurred speech, vision change, weakness in an arm or leg, loss of balance or confusion | Emergency number now | Emergency | MedlinePlus [4] |
| Headache with fever, stiff neck, nausea and vomiting | Medical help right away | Emergency | MedlinePlus [4] |
| Headache with sweating, shakiness or confusion if you use insulin or a sulfonylurea, or are a teen on Saxenda® | Check blood sugar as instructed; contact your care team | Today | Medication Guide [1]; MedlinePlus [6] |
| Headache with very little urine, dark urine or dizziness after vomiting or diarrhoea | Your prescriber the same day | Today | Medication Guide [1]; MedlinePlus [5] |
| A headache that gets worse over 24 hours, or new headaches after age 50 | Medical help the same day | Today | MedlinePlus [4] |
| Needing pain medicine for headaches three or more days a week | Your doctor | At your next appointment | MedlinePlus [4] |
