A New Era in Weight Management: A Guide to Medications and Safety
The Essentials in 10 Minutes
The new generation of weight-loss medications is neither a “magic solution” nor a purely cosmetic treatment. These are medical treatments for obesity and overweight associated with health complications, used as part of a broader healthcare strategy.
The most relevant medications currently available are semaglutide and tirzepatide. In Europe, tirzepatide for weight management is marketed under the brand name Mounjaro, while Zepbound is the brand used in the United States.
Treatment often requires continuity and regular medical follow-up. When medication is discontinued, some of the weight lost may be regained, particularly if sustainable lifestyle habits have not been established.
Introduction: What Are These New Weight-Loss Medications?
Obesity is no longer understood as simply a matter of willpower. It is recognised as a chronic, complex and relapsing disease.
Within this context, new weight-loss medications have significantly changed the medical management of obesity.
The best-known treatments belong to the group of incretin-based therapies.
Semaglutide acts on the GLP-1 receptor, while tirzepatide acts on two pathways: GIP and GLP-1.
Both medications can help:
Reduce appetite.
Increase feelings of fullness.
Reduce food intake.
Improve metabolic parameters.
What Options Are Currently Available?
The most relevant medical treatments for weight loss currently include:
Wegovy — semaglutide.
Mounjaro — tirzepatide in Europe.
Saxenda — liraglutide.
Wegovy and Mounjaro are administered once a week, while Saxenda is administered daily.
In the clinical trials included in their product information:
Semaglutide 2.4 mg produced an average weight reduction of approximately 14.9% in one major study.
In another study involving intensive lifestyle intervention, the average reduction was approximately 16.0%.
Tirzepatide produced average reductions of approximately 15.4%, 19.9% and 22.9%, depending on the dose, in the SURMOUNT-1 trial.
In a direct comparative study, tirzepatide produced an average weight reduction of 21.6%, compared with 15.4% for semaglutide.
It is important not to confuse the different brand names.
Wegovy is authorised for weight management in Europe.
In Europe, tirzepatide for weight management is included in the product information for Mounjaro.
Other medications remain available, including orlistat and naltrexone/bupropion, although they now tend to play a more secondary role.
The therapeutic framework of the European Association for the Study of Obesity places tirzepatide and semaglutide among the preferred treatment options in many clinical situations.
Liraglutide and naltrexone/bupropion may be considered alternative or second-line treatments for selected patients.
Semaglutide and Tirzepatide: What Is the Difference?
The main difference is their mechanism of action.
Semaglutide acts on one hormonal pathway: GLP-1.
Tirzepatide acts on two pathways: GIP and GLP-1.
In practical terms, both medications reduce hunger and food intake. However, tirzepatide has shown greater average weight loss in clinical trials.
This does not mean that tirzepatide is automatically the best option for everyone.
The choice of treatment depends on:
The clinical indication.
Existing medical conditions.
Treatment tolerance.
Medication availability.
The individual medical assessment.
How Do These Medications Work in the Body?
These medications do not directly “burn fat”.
Instead, they modify biological signals related to hunger, satiety and metabolism.
In the Brain
They help patients feel full sooner and reduce appetite.
In the Stomach
They delay gastric emptying, helping the feeling of fullness last longer.
In Glucose Metabolism
They improve insulin secretion and reduce glucagon levels in a glucose-dependent manner.
The Wegovy product information also explains that weight loss occurs primarily through a reduction in fat mass, although some loss of lean body mass may also occur.
Who Can Use Them?
These medications are not intended for anyone who simply wants to lose a few kilograms for cosmetic reasons.
In general, they are used in adults with:
A body mass index of 30 kg/m² or higher, or
A body mass index of 27 kg/m² or higher when at least one weight-related health condition is present.
These associated conditions may include:
High blood pressure.
Dyslipidaemia.
Type 2 diabetes.
Cardiovascular disease.
Obstructive sleep apnoea.
These criteria are reflected in the European product information for Mounjaro for weight management and in the approved indications for other anti-obesity medications in this class.
Who Should Not Take These Medications?
There are clear contraindications.
These treatments must not be used during pregnancy.
For semaglutide, the European product information also states that it should not be used during breastfeeding.
For tirzepatide, the European product information states that an individual decision should be made regarding whether to discontinue breastfeeding or discontinue or avoid treatment, taking into account the benefits for both the mother and the infant.
Semaglutide and tirzepatide are also contraindicated in people with:
A personal history of medullary thyroid carcinoma.
A family history of medullary thyroid carcinoma.
Multiple endocrine neoplasia syndrome type 2, or MEN2.
Why Should People with Medullary Thyroid Carcinoma or MEN2 Avoid Them?
This is one of the most important safety warnings.
In studies involving rodents, these medications caused thyroid C-cell tumours.
C cells are the cells involved in medullary thyroid carcinoma.
It has not been definitively demonstrated that the same effect occurs in humans. However, the clinical relevance of the animal findings has not been ruled out.
For this reason, the official product information maintains the contraindication.
In simple terms, when someone already has a genetic predisposition or relevant history associated with this type of tumour, it is not considered appropriate to accept a potential safety uncertainty with these medications.
Benefits and Limitations
The main benefit is clinically significant weight loss, but this is not the only potential benefit.
Some medications have demonstrated additional advantages.
In the United States, the FDA has approved Wegovy to reduce the risk of major cardiovascular events in certain adults with cardiovascular disease and obesity or overweight.
The European product information for Mounjaro also includes weight management, and the European Medicines Agency has assessed its use in obesity-related contexts.
However, one important limitation remains: obesity is a chronic disease.
When treatment is discontinued, a significant proportion of the weight lost may be regained if changes in diet, physical activity, sleep and the patient’s broader environment have not been consolidated.
What Role Do Orlistat and Naltrexone/Bupropion Play Today?
Orlistat and naltrexone/bupropion remain available options, but they generally play a more limited role than modern incretin-based treatments.
The main reason is efficacy.
On average, semaglutide and tirzepatide achieve greater weight loss.
Orlistat
Orlistat has a gastrointestinal side-effect profile that can significantly limit tolerance in everyday use.
Possible side effects include:
Fatty stools.
Oily spotting.
Urgency to use the toilet.
Oily bowel movements.
Faecal incontinence.
Naltrexone/Bupropion
Naltrexone/bupropion also has a more limited role because of its contraindications and the formal warning concerning suicidal thoughts and behaviour associated with the bupropion component.
This does not mean that these medications are useless.
They may still be appropriate for selected patients when incretin-based therapies:
Are not clinically suitable.
Are unavailable.
Are not tolerated.
Cannot be used for medical or financial reasons.
Safety and Common Side Effects
The most common side effects are gastrointestinal, particularly when starting treatment or increasing the dose.
They may include:
Nausea.
Vomiting.
Diarrhoea.
Constipation.
Acid reflux.
Abdominal discomfort.
Gallbladder problems may also occur.
Severe vomiting or diarrhoea can cause dehydration and may worsen kidney function.
One important warning sign is severe and persistent abdominal pain, particularly when it spreads to the back.
This may suggest pancreatitis and requires urgent medical assessment.
NAION: What Does It Mean in Simple Terms?
NAION stands for non-arteritic anterior ischaemic optic neuropathy.
In simple terms, it means that part of the optic nerve—the “cable” connecting the eye to the brain—suddenly stops receiving enough blood.
When this happens, the patient may experience:
Sudden loss of vision.
Significant blurred vision.
A shadow affecting part of the visual field.
Rapid deterioration of vision.
It most commonly affects one eye.
In 2025, the European Medicines Agency recommended that NAION be included as a very rare side effect of semaglutide-containing medications.
This does not mean that it is common. It is considered very uncommon.
However, patients should be aware of it.
Anyone taking semaglutide who develops sudden vision loss or a significant change in vision should seek medical attention immediately.
If NAION is confirmed, semaglutide should be discontinued.
What Has the FDA Recently Said About Suicide Risk?
The FDA is the United States Food and Drug Administration.
In March 2026, following a comprehensive review of the available evidence, the FDA stated that it had not found an increased risk of suicidal thoughts or behaviour with GLP-1 receptor agonists.
It requested the removal of this warning from the product information for Saxenda, Wegovy and Zepbound where it was still included.
The review included:
91 placebo-controlled clinical trials.
More than 107,000 patients.
Observational data.
Information from the FDA Sentinel System.
In practical terms, the FDA currently does not consider there to be evidence that semaglutide, tirzepatide or liraglutide increase the risk of suicide.
Even so, anyone experiencing significant mood changes, hopelessness or thoughts of self-harm should seek medical attention promptly, as these symptoms should always be taken seriously.
It is also important not to place all weight-loss medications into the same category.
Contrave — naltrexone/bupropion continues to carry a specific warning regarding suicidal thoughts and behaviour associated with bupropion.
What Should I Do If I Have Surgery Scheduled?
Always inform your surgeon, anaesthetist and medical team that you are taking one of these medications.
These drugs delay gastric emptying.
This may increase the likelihood that food or liquid remains in the stomach despite following standard fasting instructions.
During general anaesthesia or deep sedation, stomach contents could enter the airways and lungs. This is known as pulmonary aspiration.
The UK Medicines and Healthcare products Regulatory Agency, based on a European review, has indicated that this risk applies to both GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists.
The situation should be assessed individually before surgery.
Do Not Buy These Medications Online or Through Unregulated Channels
The FDA has warned about unapproved products falsely labelled as semaglutide or tirzepatide.
This includes products sold as:
“For research use only.”
“Not for human consumption.”
Some of these products have nevertheless been sold directly to consumers.
Buying medication outside regulated healthcare and pharmacy channels may expose patients to products that are:
Counterfeit.
Contaminated.
Incorrectly dosed.
Of unknown quality.
Medical Follow-Up: Your Treatment Roadmap
A complete clinical assessment should be carried out before starting treatment.
For many patients, this includes reviewing:
Medical history.
Current medication.
Potential contraindications.
Realistic treatment goals.
Baseline blood test results.
The dose is then usually increased gradually, often every four weeks, to improve tolerability.
These medications must not be combined with other products from the same drug class without medical supervision.
Healthy Lifestyle Habits as the Foundation of Treatment
This is probably the most important message in the article.
Medication can help, but it does not replace the foundation of treatment.
Current clinical guidelines and therapeutic frameworks emphasise that these medications should be used alongside:
A reduced-calorie diet.
Increased physical activity.
They should not be used instead of these measures.
Healthy habits can:
Help maintain weight loss.
Reduce the likelihood of weight regain after stopping treatment.
Improve physical fitness.
Support muscle preservation.
Improve sleep.
Enhance overall cardiometabolic health.
The Importance of Strength Training
Strength training plays a particularly important role.
When someone loses weight, part of that reduction may come from muscle mass.
Resistance exercise can help:
Preserve muscle.
Maintain physical function.
Promote healthier weight loss.
The goal should not simply be to “lose kilograms”.
It should be to reduce body fat, preserve muscle and improve overall health.
Frequently Asked Questions
Are These Medications a Quick or Permanent Solution?
No.
They are neither a shortcut nor a permanent solution on their own.
They are considered an adjunct to a reduced-calorie diet and increased physical activity.
Clinical experience and research also show that some of the weight lost may be regained when treatment is discontinued, particularly when sustainable lifestyle changes have not been established.
Which Medication Is Most Effective for Weight Loss?
Based on comparative evidence available in early 2026, tirzepatide has shown greater average weight loss than semaglutide.
In the comparative study included in the European Mounjaro product information, tirzepatide produced an average weight reduction of 21.6%, compared with 15.4% for semaglutide after 72 weeks.
What Is “Ozempic Face”?
“Ozempic face” is not a medical diagnosis.
It is a popular expression used to describe the facial appearance of some people after rapid or substantial weight loss.
The face may appear:
Thinner.
Less full.
More hollow.
More lined or wrinkled.
This is not unique to Ozempic or semaglutide.
It can occur with any significant weight loss.
Can These Medications Affect My Vision?
In very rare cases, semaglutide has been associated with NAION, a condition affecting the optic nerve that can cause sudden vision loss.
Anyone experiencing a significant visual change should seek urgent medical attention.
What Happens If I Have Surgery Scheduled?
Inform your surgeon and anaesthetist.
These medications delay stomach emptying and may increase the risk of stomach contents entering the lungs during general anaesthesia or deep sedation.
Can I Take Them If I Am Planning a Pregnancy?
This is not recommended.
The European product information for Wegovy states that semaglutide should be discontinued at least two months before a planned pregnancy.
The European product information for Mounjaro states that tirzepatide should be discontinued at least one month before a planned pregnancy.
Can I Use Them During Pregnancy or Breastfeeding?
They must not be used during pregnancy.
Semaglutide should not be used while breastfeeding.
For tirzepatide, the European product information states that the decision should be individualised, taking into account whether to discontinue breastfeeding or discontinue or avoid treatment, based on the benefits to the mother and infant.
Do These Medications Affect Oral Contraceptives?
The European tirzepatide product information noted a reduction in some pharmacokinetic parameters of oral contraceptives after a single dose.
However, the document concludes that this is not considered clinically relevant and that no dose adjustment is required.
The European semaglutide product information does not indicate that oral contraceptive effectiveness is expected to be reduced.
Is It Safe to Buy Compounded or Online Versions?
It is not recommended.
Products purchased through social media, unregulated websites or informal channels may be:
Counterfeit.
Contaminated.
Incorrectly dosed.
Of unknown composition.
Do I Need a Prescription?
Yes.
All these medications require a medical prescription.
A clinical assessment is necessary before treatment to confirm that the medication is appropriate and safe for the individual patient.
Conclusion: Realistic Expectations
These medications have significantly changed the treatment of obesity.
However, they do not replace healthy eating, physical activity or medical follow-up.
The goal should not be to reach an aesthetic “ideal weight”.
The aim should be to achieve a healthier weight, lower cardiometabolic risk and improve quality of life.
An assessment by a healthcare professional experienced in obesity medicine or endocrinology remains the best way to determine whether these treatments are appropriate for each patient.
Final Message
Maintaining a healthy weight is not simply about the number on the scales.
It is about protecting:
Heart health.
Metabolic health.
Mobility.
Long-term wellbeing.
Identifying obesity or overweight associated with increased risk, assessing each case correctly and introducing healthy habits or medical treatment when necessary can make a major difference in preventing:
Type 2 diabetes.
Cardiovascular disease.
Obstructive sleep apnoea.
Fatty liver disease.
Other complications associated with excess weight.
At DomoMed Salud, we are committed to providing accessible, rigorous medical care based on the best available scientific evidence.
Our goal is to provide clear information and high-quality medical support to help you protect your health and the health of your loved ones.
Thank you for trusting DomoMed Salud.
The DomoMed Salud Team
Bibliography and Reference Sources
This article was prepared using regulatory sources and technical reference documents current as of March 2026.
The main sources include:
The European Medicines Agency.
The United States Food and Drug Administration.
The UK Medicines and Healthcare products Regulatory Agency.
Current therapeutic frameworks from the European Association for the Study of Obesity.
Relevant references include:
The European product information for Wegovy.
The European product information for Mounjaro.
The European product information for Saxenda.
The FDA’s March 2026 safety update concerning GLP-1 receptor agonists and suicide risk.
The European Medicines Agency recommendation regarding NAION associated with semaglutide.
Medical Disclaimer
The information contained in this article is intended for informational and educational purposes only.
It does not replace an individual medical assessment, clinical diagnosis or advice from a qualified healthcare professional.
If you have concerns about your weight, treatment, side effects or whether these medications are appropriate for you, consult your doctor for a personalised assessment.
