Ozempic, Wegovy, and Mounjaro: What They Are, How They Work, and Natural Alternatives

If you've spent the last few months hearing about Ozempic, Wegovy, and Mounjaro — whether in the news, on social media, or in conversations — you're not alone. These medications have become the most discussed names when the topic is weight loss and obesity treatment.

But what exactly are they? How do they work? And what happens to your weight when you stop taking them?

In this guide, you'll find everything you need to know: what science says, the real results, documented risks, what happens after stopping — and natural alternatives for those who are not candidates or prefer another approach.

What Are Ozempic, Wegovy, and Mounjaro

Ozempic, Wegovy, and Mounjaro are injectable medications that belong to a pharmacological class called GLP-1 receptor agonists (or, in the case of Mounjaro, a dual GLP-1/GIP agonist).

They were initially developed for the treatment of type 2 diabetes, but their effects on weight loss became so significant that some versions have been repurposed specifically for the treatment of obesity.

The Differences Between Them

Ozempic (semaglutide) — approved for type 2 diabetes, with doses up to 1mg weekly. Used off-label for weight loss.

Wegovy (semaglutide) — the same molecule as Ozempic, but in higher doses (up to 2.4mg weekly) and specifically approved for obesity and overweight with comorbidities.

Mounjaro (tirzepatide) — approved for type 2 diabetes (doses up to 15mg weekly), but with weight loss results superior to semaglutide due to its dual mechanism of action. The version approved for obesity is called Zepbound (not yet available in Portugal in 2026).

How They Work: The GLP-1 Mechanism

GLP-1 (glucagon-like peptide-1) is a hormone naturally produced in the small intestine after meals. Its role is to regulate appetite, satiety, and blood glucose levels.

When you eat, GLP-1 is released and:

• Sends satiety signals to the brain — reduces appetite
• Slows gastric emptying — food stays longer in the stomach, prolonging the feeling of fullness
• Stimulates insulin release (only when glucose is high)
• Reduces glucagon production (a hormone that increases blood glucose)

The problem: natural GLP-1 is rapidly degraded in the body — within minutes. Its action is brief.

Semaglutide (Ozempic/Wegovy) is a synthetic version of GLP-1 that resists degradation. Its chemical structure has been modified to last for days instead of minutes. A weekly injection maintains constant GLP-1 levels in the body for 7 days — something the natural hormone could never achieve.

Mounjaro: The Dual Agonist

Tirzepatide (Mounjaro) goes a step further. It acts not only on the GLP-1 receptor but also on the GIP (glucose-dependent insulinotropic polypeptide) receptor — another intestinal hormone involved in glucose and fat metabolism.

This dual action amplifies the effects:

• Greater appetite reduction and longer-lasting feeling of satiety
• Maintenance of metabolic rate during weight loss (reduces the metabolic adaptation that usually sabotages diets)
• Greater fat loss relative to lean mass (better preserves muscle)

This is why tirzepatide shows superior weight loss results to semaglutide in clinical studies.

Real Results: What Clinical Studies Say

Semaglutide (Ozempic/Wegovy)

Large-scale clinical trials (STEP trials) showed:

• Average weight loss of 12-15% of body weight over 16-18 months
• About 1/3 of participants lost more than 20% of their weight
• Significant improvement in metabolic markers (blood glucose, triglycerides, blood pressure)

SELECT study (2023): demonstrated a 20% reduction in cardiovascular events (heart attack, stroke) in people with obesity and heart disease — even independently of weight loss.

Tirzepatide (Mounjaro)

Clinical trials (SURPASS and SURMOUNT trials) showed:

• Average weight loss of 15-21% of body weight — superior to semaglutide
• More than 1/3 of participants lost ≥25% of their weight (loss comparable to bariatric surgery)
• Glycemic control superior to semaglutide at equivalent doses

SURPASS-2 study (direct comparison): tirzepatide 15mg showed 96.4% higher weight loss than semaglutide 1mg in people with type 2 diabetes.

Comparative Table: Ozempic, Wegovy, and Mounjaro

Side Effects: What to Expect

Common Effects (Very Frequent)

All three medications share the same side effect profile, especially gastrointestinal ones:

• Nausea — the most common, especially in the first few weeks and after dose increase
• Vomiting
• Diarrhea
• Constipation (paradoxically, some people experience constipation instead of diarrhea)
• Abdominal pain

These effects tend to decrease over 4-8 weeks as the body adapts. The strategy of gradual dose titration (starting low and increasing slowly) minimizes this intensity.

Less Common But Relevant Effects

• Temporary hair loss — reported by some people, usually mild and reversible
• Fatigue — especially if caloric intake is very low
• Dizziness
• Reflux or heartburn — due to delayed gastric emptying

Serious Effects (Rare But Severe)

• Acute pancreatitis — inflammation of the pancreas (severe abdominal pain, persistent nausea, vomiting). Requires immediate medical attention.
• Gallbladder problems — gallstones, cholecystitis
• Hypoglycemia — when combined with insulin or sulfonylureas (diabetes medications)
• Severe allergic reactions — facial swelling, difficulty breathing
• Thyroid problems (very rare) — theoretical risk based on animal studies. Contraindicated in people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2.

Who They Are Suitable For

These medications are not recommended for anyone who wants to lose "a few pounds". Medical indications are specific:

Indication Criteria

• BMI ≥ 30 kg/m² (obesity) — regardless of other conditions
• BMI ≥ 27 kg/m² (overweight) with at least one weight-related condition — type 2 diabetes, hypertension, dyslipidemia, sleep apnea, cardiovascular disease
• Documented attempts at weight loss through lifestyle modifications (diet and exercise) over at least 6 months without sustained success

Absolute Contraindications

• Personal or family history of medullary thyroid carcinoma
• Multiple endocrine neoplasia type 2
• Pregnancy or planning pregnancy (medications should be discontinued at least 2 months before attempting to conceive)
• Breastfeeding
• Acute pancreatitis or history of chronic pancreatitis
• Severe gastrointestinal problems (diabetic gastroparesis, uncontrolled inflammatory bowel disease)

What Happens When You Stop

This is one of the most important and least discussed aspects: most people regain significant weight after discontinuing the medication.

Follow-up studies show that, one year after discontinuing semaglutide, people regained an average of two-thirds of the lost weight. Some regained all of it.

Why does this happen? GLP-1 medications do not "cure" obesity. While active, they suppress the hormonal and neurological mechanisms that perpetuate excess weight. When you stop, these mechanisms reactivate — and the body tends to return to its previous metabolic "set point".

How to Minimize Weight Regain

• Establish sustainable eating habits during treatment, not just relying on the appetite suppressant
• Create consistent physical activity routines
• Address the behavioral and emotional aspects of eating (with a psychologist or nutritionist)
• Consider long-term maintenance — whether with reduced doses of the medication, transitioning to natural alternatives, or intensive nutritional support

Natural Alternatives: For Those Who Prefer Another Approach

Not everyone is a candidate for medication. Many prefer natural approaches. And there are ingredients with scientific research that can support weight management goals — working with some of the same mechanisms as GLP-1s, but in a milder and natural way.

How to Increase GLP-1 Naturally

Soluble fiber — has been shown to increase natural GLP-1 production in the gut. Sources: oats, legumes, apples, carrots, sweet potatoes.

Adequate protein — stimulates the release of GLP-1 and PYY (another satiety hormone). Studies show that 25-30% of daily calories from protein significantly reduces appetite.

Omega-3 fatty acids — research suggests they may increase sensitivity to GLP-1 signals.

Natural Ingredients with Research in Metabolism and Satiety

EGCG (from green tea): Studies indicate that EGCG can support natural thermogenesis and fat oxidation. Research also reveals a 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 due to its binding with tannins.

L-Carnitine: Facilitates the transport of fatty acids to mitochondria where they are converted into energy — especially relevant in the context of physical exercise.

Raspberry Extract: Preliminary research suggests it may support appetite regulation and blood sugar balance.

Niacin (Vitamin B3): Supports efficient energy metabolism — when the body adequately converts food into energy, hunger signals tend to be more stable.

The Kyoslim combines these five ingredients 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

Can I take Ozempic just to lose a few pounds?

No. Ozempic, Wegovy, and Mounjaro are prescription medications for the treatment of obesity or diabetes — not for cosmetic weight loss. Use outside approved indications is not only inappropriate, it is potentially dangerous and denies access to those who genuinely need it.

Which is more effective: Ozempic, Wegovy, or Mounjaro?

Wegovy (semaglutide 2.4mg) is more effective than Ozempic (semaglutide 1mg) simply because the dose is higher. Mounjaro (tirzepatide) demonstrates superior results to both due to its dual mechanism of action — but the "best" option depends on individual profile, tolerance, availability, and cost.

Are they safe long-term?

Long-term safety data is still limited — semaglutide and tirzepatide are relatively new medications. Studies up to 2-3 years show an acceptable safety profile in most people, but effects at 10+ years are still unknown and are being studied.

How much do they cost?

In Portugal, prices vary between €200-400/month depending on dose and availability. Reimbursement depends on the indication (diabetes vs. obesity). Many health insurance plans do not cover weight loss medication.

Can I use natural ingredients while taking the medication?

Always consult your doctor before combining any supplement with prescription medication. Some ingredients (especially those that affect blood pressure or blood glucose) can interact.

Will I regain all the weight if I stop?

Most people regain most of the weight — but not necessarily all. The decisive factor is what you did during treatment: if you established sustainable habits, recovery will be less. If you used the medication as an isolated solution, recovery will be almost complete.

Important Health Information

Warning: This article is for educational purposes only. Ozempic, Wegovy, and Mounjaro are prescription medications that should 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.