Weight loss medications have become one of the most discussed topics in health and wellness in recent years — especially since names like Ozempic, Wegovy, and Mounjaro entered everyday conversations.
But the reality is more complex than sensationalist headlines suggest. These medications exist, work for some people in specific contexts, have documented risks — and are not the only option available.
In this guide, you will find factual information about the most commonly used weight loss medications in 2026: what they are, how they work, for whom they are suitable, their risks, and — finally — natural alternatives for those who are not candidates or prefer a non-pharmacological approach.
The Current Landscape: Why These Medications Are Everywhere
According to the World Health Organization, more than 1 billion people worldwide live with obesity — a chronic disease associated with type 2 diabetes, cardiovascular diseases, certain types of cancer, and a significant reduction in quality of life and life expectancy.
Traditional approaches — diet and exercise — produce modest results in the medium to long term for most people. The weight regain rate after loss through caloric restriction is over 80% in 5 years.
It is in this context that pharmacological weight loss medications have gained relevance — not as substitutes for a healthy lifestyle, but as adjuncts in cases where obesity represents a significant medical risk.
GLP-1 Receptor Agonists: The New Generation
GLP-1 (glucagon-like peptide-1) is a hormone naturally produced in the gut that regulates appetite, satiety, and blood glucose levels. GLP-1 agonist medications mimic this hormone, amplifying its effects.
Semaglutide: Ozempic and Wegovy
What they are: Ozempic and Wegovy contain the same active ingredient — semaglutide. The difference lies in the dose and the approved indication. Ozempic was developed for type 2 diabetes (doses up to 1mg). Wegovy is specifically approved for obesity and overweight (doses up to 2.4mg).
How they work: Semaglutide is a GLP-1 receptor agonist that:
- Reduces appetite and increases feelings of satiety
- Slows gastric emptying (food stays in the stomach longer)
- Improves blood glucose regulation
- Reduces glucose production by the liver
Results: Clinical studies show an average weight loss of 12-15% of body weight over 16-18 months when combined with lifestyle modifications.
Administration: Subcutaneous injection once a week.
Common side effects: Nausea, vomiting, diarrhea, constipation. Generally more intense in the first few weeks and decrease with adaptation. The dose is gradually increased to minimize these effects.
Serious side effects (rare but serious): Acute pancreatitis, gallbladder problems, hypoglycemia (when combined with other diabetes medications), severe allergic reactions. Temporary hair loss.
Contraindications: Personal or family history of medullary thyroid carcinoma, multiple endocrine neoplasia type 2, pregnancy, breastfeeding, children under 12 years of age.
Tirzepatide: Mounjaro and Zepbound
What it is: Tirzepatide is a dual agonist — it activates both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors. This dual action makes it more potent than semaglutide.
Results: Clinical studies show an average weight loss of 15-21% of body weight — the most expressive results among currently approved medications.
Administration: Subcutaneous injection once a week. Doses range from 2.5mg to 15mg.
Side effects: Similar to semaglutide, but with a slightly higher incidence of gastrointestinal effects at higher doses.
Liraglutide: Saxenda
What it is: Another GLP-1 agonist, but with a shorter duration of action than semaglutide.
Results: Average weight loss of 5-10% of body weight.
Administration: Daily injection (not weekly like semaglutide and tirzepatide).
Practical difference: The need for daily injection reduces long-term adherence compared to weekly options.
Other Approved Weight Loss Medications
Orlistat (Xenical, Alli)
How it works: Inhibits gastrointestinal lipase — the enzyme that digests fat. Result: about 30% of ingested fat is not absorbed and is eliminated in the feces.
Results: Modest weight loss — 3-5% of body weight. It is the medication with the most modest results among those approved.
Administration: Oral capsule three times a day with meals.
Side effects: Almost exclusively gastrointestinal — oily stools, fecal urgency, flatulence with discharge, fecal incontinence in extreme cases. These effects are more pronounced when the person consumes high-fat meals — which ends up acting as an additional incentive to avoid fatty foods.
Advantage: Available without prescription (Alli version, with half the dose). Does not act on the central nervous system.
Naltrexone/Bupropion (Contrave)
How it works: Combination of two medications — naltrexone (used in addiction treatment) and bupropion (antidepressant). Together, they act on brain areas that regulate appetite and the food reward system.
Results: Average weight loss of 5-6% of body weight.
Administration: Oral tablets twice a day.
Side effects: Nausea, constipation, headache, dizziness. May increase blood pressure — requires monitoring. Increased risk of suicidal thoughts (known effect of bupropion) — contraindicated in people with a history of severe depression.
Phentermine/Topiramate (Qsymia)
How it works: Phentermine is an appetite suppressant (central nervous system stimulant). Topiramate is an anticonvulsant that also reduces appetite.
Results: Weight loss of 7-9% of body weight — among the most effective of non-GLP-1 medications.
Administration: Oral capsule once a day.
Side effects: Dry mouth, constipation, paresthesia (tingling), taste changes, insomnia. May increase heart rate. Highly contraindicated in pregnancy (risk of fetal malformations).
Limitation: Phentermine is classified as a controlled substance due to its abuse potential. It is generally not recommended for use longer than 12 weeks.
Comparative Table: Weight Loss Medications
| Medication | Mechanism | Average Weight Loss | Administration | Main Limitation |
|---|---|---|---|---|
| Tirzepatide (Mounjaro) | GLP-1 + GIP Agonist | 15-21% | Weekly injection | High cost, gastrointestinal effects |
| Semaglutide (Wegovy) | GLP-1 Agonist | 12-15% | Weekly injection | High cost, gastrointestinal effects |
| Liraglutide (Saxenda) | GLP-1 Agonist | 5-10% | Daily injection | Daily injection reduces adherence |
| Phentermine/Topiramate (Qsymia) | Appetite suppressant + anticonvulsant | 7-9% | Oral daily | Controlled substance, central nervous system effects (dizziness, insomnia, mood changes, etc.) |
| Naltrexone/Bupropion (Contrave) | Reward system + antidepressant | 5-6% | Oral 2x/day | Risk of depression, blood pressure |
| Orlistat (Xenical) | Fat absorption inhibitor | 3-5% | Oral 3x/day | Severe gastrointestinal effects, modest efficacy |
Who Are They Suitable For
Weight loss medications are not recommended for everyone who wants to lose a few pounds. Medical indications are specific:
- BMI ≥ 30 kg/m² (obesity) — regardless of other conditions
- BMI ≥ 27 kg/m² (overweight) with at least one weight-related comorbidity — type 2 diabetes, hypertension, dyslipidemia, sleep apnea
- Documented failure of weight loss through lifestyle modifications (diet and exercise) over at least 6 months
These are prescription medications that require regular follow-up — not only for monitoring results, but for early detection of side effects.
What Happens After Stopping
This is one of the least discussed but most important aspects: most people regain significant weight after discontinuing the medication.
A follow-up study of people who used semaglutide showed an average regain of two-thirds of the lost weight in the first year after stopping the medication. GLP-1 medications do not "cure" obesity — they suppress the mechanisms that perpetuate it while they are active.
For long-term maintenance of results, it is essential to:
- Establish sustainable eating habits during treatment
- Create consistent physical activity routines
- Address the behavioral and psychological aspects of eating
- Consider continuous support — whether through continued medication, transition to natural alternatives, or intensive nutritional monitoring
Natural Alternatives: For Those Who Prefer Non-Pharmacological Approaches
Not everyone is a candidate for medication. Many prefer natural approaches. And there are ingredients with scientific research that can support weight management goals — without the risks and costs of pharmacological medications.
Natural Ingredients with Research in Appetite and Metabolism Regulation
EGCG (from green tea): Studies suggest that EGCG can support natural thermogenesis and fat oxidation. Research also indicates a potential role in regulating hunger hormones — leptin and ghrelin.
Guarana (natural caffeine): Caffeine has a documented effect of moderate appetite suppression and increased thermogenesis. Guarana offers gradual release of caffeine due to its binding with tannins.
L-Carnitine: Facilitates the transport of fatty acids to the mitochondria where they are converted into energy — especially relevant in the context of physical exercise.
Dietary fiber: Soluble fiber naturally increases GLP-1 production in the gut — the same mechanism that medications mimic, but in a gentler and more natural way.
Adequate protein: Stimulates the release of satiety hormones (GLP-1, PYY) and has the highest thermic effect among macronutrients.
Kyoslim combines EGCG, Guarana, L-Carnitine, Raspberry Extract, and Niacin in a natural formula manufactured in the European Union with DGAV authorization — an option for those seeking metabolic support through natural ingredients, without medication.
Frequently Asked Questions
Are GLP-1 medications safe long-term?
Long-term safety studies are still limited — semaglutide and tirzepatide are relatively recent. Data up to 2-3 years show an acceptable safety profile in most people, but effects at 10+ years are still being studied. Use should always be accompanied by a doctor.
Can I take these medications just to lose a few pounds?
They are not recommended for cosmetic weight loss. They are medications for the treatment of obesity or overweight with comorbidities — medical conditions that pose a health risk. Use outside these indications is not only inappropriate, it is potentially dangerous.
How much do they cost?
GLP-1 medications (Ozempic, Wegovy, Mounjaro) are expensive — between €200-400/month without reimbursement. In Portugal, reimbursement depends on the indication (diabetes vs. obesity) and specific conditions. Many health insurances do not cover weight loss medication.
Can I use natural alternatives in combination with medication?
Always consult your doctor before combining any supplement with prescription medication. Some natural ingredients (especially those containing caffeine or affecting blood glucose) can interact with medications.
If I stop the medication, will I regain all the weight?
Most people regain significant weight — but not necessarily all. The most important factor is what you did during treatment: if you established sustainable habits, the regain will be less. If you used the medication as an isolated solution without lifestyle changes, the regain will be almost total.
Important Health Information
Disclaimer: This article is for educational and informational purposes only. The mentioned medications are prescription drugs that must be used exclusively under medical supervision. Never start, stop, or change medication without consulting your doctor. Obesity is a complex disease that requires individualized medical evaluation. The natural supplements mentioned are not intended to diagnose, treat, cure, or prevent any disease and do not replace prescribed medication. Always consult your healthcare professional before starting any supplementation regimen.
The statements in this article have not been evaluated by regulatory authorities.
