Health · Pharma & Biotech · 9 hrs ago
Experts warn some cold medicines may pose risks for weight-loss jab users
Experts in the UK warn that some cold medicines may be risky for people using weight-loss injections such as Mounjaro and Wegovy.
About 1.6 million UK adults use these medicines, which can affect how swallowed medicines are absorbed and may reduce thirst.
Illness can add to dehydration, especially when fever, sweating, vomiting or diarrhoea cause fluid loss.
Anti-inflammatory painkillers such as ibuprofen may increase the risk of kidney injury when someone is dehydrated.
Some sedating antihistamines may worsen constipation, a side effect of these injections.
Decongestants such as pseudoephedrine may raise blood sugar, so people with type 2 diabetes are advised to monitor their levels closely or avoid them.
The warnings matter because common remedies can add to existing side effects, but the material provided does not specify which alternatives to take.
Experts warn that some common cold and flu medicines may pose risks for people using weight-loss injections such as Mounjaro and Wegovy.
Dr Dean Eggitt says the medicines can affect how swallowed drugs are absorbed and may increase unexpected side effects.
Ibuprofen and naproxen may raise the risk of acute kidney injury when a person is dehydrated.
Sedating antihistamines such as diphenhydramine may worsen constipation, a possible side effect of GLP-1 drugs.
People with type 2 diabetes are advised to monitor blood sugar closely when taking decongestants, or avoid them.
- Who
- People using weight-loss injections, including Mounjaro and Wegovy. Experts quoted include GP Dr Dean Eggitt and pharmacist Rachel Jones.
- What
- Experts warn that some cold and flu medicines could worsen side effects or create other risks for weight-loss jab users.
- When
- During cold and flu season. The article was published on 8 November 2026.
- Where
- The UK.
- Why
- The injections can affect absorption of swallowed medicines and may contribute to dehydration and constipation. Some decongestants can also raise blood sugar.
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- UK adults using weight-loss injections
- 1.6 million
- Weight-loss injections named
- Mounjaro and Wegovy
- Painkillers discussed
- Ibuprofen and naproxen
- Sedating antihistamine ingredient
- Diphenhydramine
- Decongestants discussed
- Phenylephrine and pseudoephedrine
What people are saying
These medications affect absorption of medicines that are swallowed
GLP-1 drugs effectively mute thirst, increasing dehydration risk
Dehydration is one of the biggest risks to be aware of when taking weight loss treatments, particularly during cold and flu season.