Safety
How this is kept safe — and what to watch for.
Weight-management medication is effective and it has real risks. This page sets out how eligibility is screened, what side effects are common, and when to seek help urgently.
When to seek urgent care
Contact emergency services or go to an emergency department if you have severe or persistent abdominal pain, repeated vomiting with signs of dehydration, symptoms of a serious allergic reaction such as swelling of the face or difficulty breathing, or sudden changes in vision. Do not wait for a reply to a message.
Instructions from a doctor who has examined you always override anything written here or anywhere else in the app.
Screening comes before treatment
The single most important safety mechanism is that a licensed doctor decides whether treatment is appropriate, before anything is prescribed. That decision uses your medical history, your current medicines and your weight history — which is why the assessment asks for detail that can feel excessive.
A doctor may decline treatment, ask for more information, or ask you to resolve something with your own doctor first. Those outcomes are the screening working, not failing.
Things that commonly rule treatment out
This is not a complete list, and only a clinician can apply it to you. It is here so you know what will be asked about and why.
- Pregnancy, breastfeeding, or trying to conceive
- Certain personal or family medical histories that make specific treatments unsuitable
- A history of pancreatitis
- An active eating disorder, which needs different care rather than weight-loss medication
- Medicines that interact unsafely, or conditions that change how medication is absorbed
- A body mass index below the clinical threshold for treatment
- An unstable medical condition that should be treated first
Side effects
Commonly reported
Gastrointestinal effects are the most frequently reported, and they are usually most noticeable when a dose is first started or increased.
- Nausea
- Vomiting
- Diarrhoea
- Constipation
- Reflux or indigestion
- Fatigue
- Headache
- Injection-site reactions
Less common but serious
These are uncommon. They matter because they need prompt medical attention rather than waiting.
- Pancreatitis — severe, persistent abdominal pain, often spreading to the back, with vomiting
- Gallbladder problems, including gallstones, which become more likely with rapid weight loss
- Dehydration and kidney strain from prolonged vomiting or diarrhoea
- A serious allergic reaction
- Low blood sugar, particularly if you also take medication for diabetes
- Sudden changes in vision
Rapid weight loss has its own risks
Losing weight quickly is not automatically better. Faster loss increases the likelihood of gallstones, and some of the weight lost is lean tissue rather than fat. This is why adequate protein intake and resistance exercise are part of the clinical advice, and why a doctor may deliberately slow a dose increase.
If weight is falling faster than expected, that is a reason to tell the care team, not a result to celebrate quietly.
Stopping treatment
Weight regain after stopping is common and well documented in clinical trials, and it is graded rather than all-or-nothing — how much returns depends partly on what happens next. Stopping is a clinical decision worth planning with a doctor, including what support continues afterwards.
Do not stop, restart or change a dose on your own. Talk to a clinician first.
Reporting a side effect
Tell the care team through the app so it can be recorded and reviewed clinically. You can also report a suspected adverse reaction yourself to the Spanish medicines regulator through its pharmacovigilance system for patients, independently of us. Both routes matter: yours helps you, and the regulator's helps everyone.
Free assessment. Membership starts only after a clinician reviews your case.