Weight Loss Injections: What Really Works in 2025 (Best Shots, Science & Safety)

In recent years, weight loss injections have become one of the most talked-about solutions for people looking to shed extra pounds. You may have heard about names like Ozempic, Wegovy, or Zepbound through friends, social media, or even your doctor. But are these weight loss shots really effective? Are they safe? And which ones are considered the best for 2025?

In this article, we’ll explore everything you need to know about weight loss injectables, including how they work, what options are available, who they’re for, and what the science says. We’ll also touch on safety, side effects, and whether you need to take them forever. Let’s break it all down in simple terms so that anyone, even a high school student, can understand what these weight reduction injections are all about.

Why Are Weight Loss Injections So Popular Right Now?

The buzz around weight loss injections isn't just hype—it's backed by real science and results. As obesity rates continue to climb globally, doctors and researchers have been working to find more effective tools to help people lose weight safely.

According to the CDC, nearly 42% of adults in the U.S. are considered obese. This has serious implications for public health, increasing the risk of heart disease, diabetes, stroke, and even certain cancers. Traditional methods like diet and exercise are essential, but for many people, they aren’t enough. That’s where weight loss injections come in.

These shots work by mimicking natural hormones in the body that help control appetite and blood sugar. Some people taking them report losing 15% or more of their body weight—a level of success that was previously hard to achieve without surgery.

What Are Weight Loss Injections?

Weight loss injections are prescription medications delivered through a shot, usually once a week. Most of these injections are based on a class of drugs known as GLP-1 receptor agonists. GLP-1 stands for "glucagon-like peptide-1," a natural hormone your body produces after you eat.

Dr. Ania Jastreboff, an obesity researcher at Yale University, explains, “GLP-1 medications help regulate appetite and improve blood sugar control. They send signals to your brain that make you feel full sooner and reduce cravings.”

Some newer medications also combine GLP-1 with GIP (glucose-dependent insulinotropic polypeptide), another hormone that enhances insulin release and reduces food intake. Together, these make injections even more effective.

These medications were originally developed to treat type 2 diabetes, but researchers noticed that people on them were also losing a lot of weight. That discovery led to FDA approval for weight management in people with or without diabetes.

The Best Weight Loss Injections in 2025

So, which injections are the most effective right now? Here are the top contenders based on current scientific evidence and clinical use:

1. Wegovy (semaglutide)

What It Is: Wegovy is a once-weekly injectable prescription medication developed by Novo Nordisk. It contains semaglutide, a GLP-1 receptor agonist originally used to treat type 2 diabetes under the brand name Ozempic.

How It Works: Wegovy mimics a natural hormone called GLP-1 (glucagon-like peptide-1), which helps control blood sugar and appetite. It slows digestion and sends signals to the brain that you’re full, reducing how much food you eat.

Typical Dosage: Wegovy starts at 0.25 mg per week and is gradually increased to 2.4 mg weekly over several weeks.

Effectiveness:

• In the STEP 1 clinical trial, adults taking Wegovy lost an average of 15% of their body weight over 68 weeks.
• Many participants lost 35 lbs or more depending on their starting weight.
• Results were significantly better than placebo.

Side Effects:

• Common: nausea, diarrhea, constipation, vomiting, headache
• Rare: pancreatitis, gallbladder issues, thyroid tumors (in animal studies)

Who It’s For:

• Adults with a BMI ≥30 (obese) or ≥27 (overweight) with at least one weight-related condition like high blood pressure or sleep apnea.

Latest News & Availability:

• As of 2025, Wegovy remains the most prescribed FDA-approved weight loss injection.
• Supply issues seen in 2023–2024 are easing as Novo Nordisk scales up production.

2. Ozempic (Semaglutide – off-label for weight loss)

What It Is: Ozempic is technically a diabetes drug, but it contains the same active ingredient (semaglutide) as Wegovy. It's often prescribed “off-label” for weight loss when Wegovy is unavailable.

How It Works: Same mechanism as Wegovy — it suppresses appetite, improves insulin sensitivity, and slows digestion.

Typical Dosage: 0.25 mg up to 2 mg weekly — slightly lower than Wegovy’s full dose.

Effectiveness:

• Users typically experience 10–14% weight loss, slightly less than Wegovy due to lower dosing.
• Still a very effective alternative, especially for those with type 2 diabetes.

Side Effects: Nearly identical to Wegovy, with GI symptoms being most common.

Who It’s For:

• Diabetics or people struggling to access Wegovy.
• May be used under medical supervision for weight loss in non-diabetics.

Latest News & Availability:

• Remains widely used off-label as a more accessible or affordable alternative to Wegovy.
• FDA does not officially endorse it for weight loss, but doctors frequently prescribe it for that purpose.

3. Zepbound (tirzepatide)

What It Is:

Zepbound is one of the newest weight loss injections on the market, from Eli Lilly. It combines GLP-1 and GIP hormones, which may make it even more effective. Some people have lost more than 20% of their body weight with Zepbound.

Dr. Robert Kushner, a professor at Northwestern University, led a study on tirzepatide and found, “This is the most effective medication we’ve seen for weight management without surgery.”

How It Works: Tirzepatide stimulates both GLP-1 and GIP, two hormones involved in appetite control and insulin regulation. This dual action is thought to be why it's even more effective than semaglutide alone.

Typical Dosage: Weekly injections starting at 2.5 mg, increasing gradually to a maintenance dose up to 15 mg.

Effectiveness:

• Clinical studies showed up to 22.5% average weight loss, or about 52 lbs, in some patients.
• In a head-to-head trial (SURMOUNT-5), Zepbound outperformed Wegovy in weight loss.

Side Effects: Similar to Wegovy, including nausea, fatigue, and GI issues. Zepbound may also cause low blood sugar in people with diabetes if used with other diabetic medications.

Who It’s For:

• Adults with obesity or those who are overweight with at least one other weight-related condition.
• Especially promising for people who didn’t respond well to GLP-1-only medications.

Latest News & Availability:

• Approved by the FDA in late 2023.
• Eli Lilly is rolling out an affordability program and expanding access in 2025.

4. Mounjaro (tirzepatide)

What It Is: Like Ozempic, Mounjaro is officially for diabetes but is used off-label for weight loss. It’s the same drug as Zepbound but may be prescribed at different doses.

How It Works: Same dual-hormone action as Zepbound (GLP-1 + GIP).

Typical Dosage: Up to 15 mg weekly.

Effectiveness:

• Users often see 20%+ weight loss, even when prescribed off-label.
• Some users say results kick in faster than semaglutide.

Side Effects: Very similar to Zepbound and Wegovy — mostly GI-related.

Who It’s For:

• People with type 2 diabetes.
• Those using it off-label while waiting for Zepbound approval or coverage.

Latest News & Availability:

• Still popular as an off-label option.
• Insurance coverage may be easier if you're diabetic.

5. Saxenda (liraglutide)

What It Is: Saxenda was one of the first weight loss injectables approved by the FDA. It’s taken daily rather than weekly and is less effective than newer options, but it still helps some people lose weight.

How It Works: Saxenda also mimics GLP-1 to reduce hunger and calorie intake, but it's less potent than semaglutide or tirzepatide.

Typical Dosage: Starts at 0.6 mg daily and increases to 3.0 mg daily.

Effectiveness:

• Clinical trials showed 5–10% weight loss, less than newer medications.
• Still effective for many who prefer daily injections or cannot tolerate semaglutide.

Side Effects: GI issues (nausea, vomiting), low appetite, fatigue.

Who It’s For:

• People who want a daily dosing option.
• Those unable to tolerate stronger GLP-1 agonists.

Latest News & Availability:

• Saxenda is still prescribed but is being slowly replaced by more effective once-weekly injections.
• A solid second-line option.

Notes:

• Wegovy and Zepbound are currently the top choices due to higher weight loss and FDA approval.
• Ozempic and Mounjaro are used off-label, meaning they’re FDA-approved for diabetes but commonly prescribed for weight loss.
• Saxenda is a daily injection and less potent but still a useful tool for certain individuals.

How Do These Injections Help You Lose Weight?

Let’s keep it simple: these shots work mainly by helping you feel full faster and stay full longer. They also slow down how quickly your stomach empties and may reduce cravings for certain foods. This makes it easier to eat less without feeling miserable.

On a chemical level, these drugs act like natural hormones that your body releases after meals. They go to your brain’s appetite centers and say, “Hey, we’re good here—no need for more food.”

They also help your body control blood sugar, which can prevent the spikes and crashes that often lead to overeating. That’s why they were first developed for diabetes but turned out to be excellent for weight loss, too.

Who Should Consider Weight Loss Shots?

Weight loss injections aren’t for everyone. They are usually prescribed for people who:

• Have a body mass index (BMI) of 30 or more (classified as obese)
• Have a BMI of 27 or more with a weight-related health condition like diabetes, high blood pressure, or sleep apnea

You should also be willing to make changes to your diet, physical activity, and lifestyle. These injections aren’t magic bullets. They’re powerful tools, but they work best when combined with other healthy habits.

Are These Injections Safe? What Are the Side Effects?

Most people tolerate weight loss injections well, but like any medication, they can cause side effects. The most common ones include:

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Headache
• Fatigue

These usually improve over time as your body gets used to the drug.

More serious side effects are rare but possible. For example, some studies have shown a small increased risk of pancreatitis or gallbladder issues. Because of this, doctors will monitor you closely.

There’s also a black box warning on some of these drugs about a possible risk of thyroid tumors, based on animal studies. However, this hasn’t been confirmed in humans.

That’s why it’s important to have an open conversation with your doctor and discuss your personal risks and health history.

Do You Have to Take Weight Loss Injections Forever?

Here’s a tough truth: many people regain weight after stopping the injections. This is because the medication is helping control your appetite and metabolism. When you stop taking it, your hunger may return, and your body might naturally try to return to its old weight.

Researchers like Dr. Andres Acosta of the Mayo Clinic say that long-term weight loss requires long-term treatment. "Obesity is a chronic condition, much like high blood pressure. If you stop treating it, it comes back."

That doesn’t mean you’ll be on these drugs forever, but it does suggest that ongoing treatment—either with medication, lifestyle, or both—is often necessary.

Some studies suggest that gradually tapering off these medications, combined with sustained lifestyle changes, may help maintain weight loss. A Danish study found that participants who slowly reduced their semaglutide dosage while adopting healthy habits maintained their weight loss 26 weeks after stopping the medication.

How Much Do Weight Loss Shots Cost?

Without insurance, these medications can be expensive. Wegovy and Zepbound, for example, can cost around $1,000 to $1,300 per month. However, some insurance plans cover them, especially if you meet certain health criteria.

Programs like GoodRx may help you find discounts. Some pharmaceutical companies also offer savings cards or patient assistance programs.

Telehealth services like Meto are making it easier to access these medications, and they often include coaching and support to improve your results.

Are There Alternatives to Weight Loss Injections?

If you’re not a good candidate for injections, or if you prefer not to use them, there are still options. Some people try oral medications like Contrave or Qsymia. Others focus on natural approaches like intermittent fasting, strength training, and tracking macros.

Supplements like berberine or inositol have gained popularity, but their effectiveness isn’t as strong or consistent as injectable medications.

In some cases, weight loss surgery (like gastric sleeve or bypass) may be recommended, especially if your BMI is very high and other methods haven’t worked.

RELATED READ: What Is Orforglipron? The New Weight Loss Pill Explained Simply

Real People, Real Results

You don’t have to look far to find people sharing their weight loss journeys on platforms like YouTube and Reddit. Many describe feeling in control of their eating for the first time in years. Others talk about increased energy, improved blood sugar, and even better sleep.

Still, it’s important to remember that results vary. What works wonders for one person might not be right for someone else.

Expert Opinions

Here are some expert voices on the topic:

• Dr. Caroline Apovian, a Harvard obesity expert, said, “These drugs are game-changers, but they should be used thoughtfully, not casually.”
• Dr. Scott Kahan of Johns Hopkins notes, “They offer hope to people who have struggled for years, but they’re just one piece of the puzzle.”

Final Thoughts

Weight loss injections are changing the way we think about obesity treatment. For many people, they offer a path to better health that finally feels possible. But they aren’t for everyone, and they aren’t a quick fix.

If you’re curious about these injection shots for weight loss, talk to a healthcare provider. Consider your goals, your health history, and your lifestyle. With the right support, tools like weight loss injectables can be powerful allies in your journey to better health.

At Meto, we believe in science-backed wellness that works. Keep reading, keep learning, and keep growing—you deserve to feel your best.

FAQs on Weight Loss Injections

1. Do weight loss injections work without diet and exercise?

While weight loss injections like Wegovy and Zepbound can cause weight loss on their own, clinical studies consistently show better results when combined with healthy eating and regular physical activity. The medications help regulate appetite and blood sugar, but lifestyle changes maximize and sustain results.

2. How fast do you lose weight with injections like Wegovy or Zepbound?

Most people start losing weight within the first few weeks of treatment. Significant weight loss — around 15–22% of body weight — typically occurs over 6 to 12 months, according to clinical trial data. However, results vary based on factors like dosage, adherence, and lifestyle.

3. Are weight loss injections covered by insurance?

Some weight loss injections, such as Wegovy and Saxenda, are covered by certain health insurance plans if prescribed for obesity. However, coverage depends on the provider and plan. Ozempic and Mounjaro, though often used off-label, may be covered if prescribed for type 2 diabetes.

4. What happens if you miss a dose of your weight loss injection?

If you miss a weekly dose, most guidelines say you can take it within 5 days. If more than 5 days pass, skip the missed dose and resume your normal schedule. Always consult your healthcare provider for instructions based on your medication.

5. Can you switch from Ozempic to Zepbound for better weight loss?

Yes, switching from Ozempic (semaglutide) to Zepbound (tirzepatide) is common, especially if you're looking for stronger weight loss effects. Zepbound targets two hunger-regulating hormones instead of one, and has shown greater average weight loss in trials. Always transition under medical supervision.

6. Are weight loss injections safe for long-term use?

Long-term safety data is still emerging, but so far, GLP-1 receptor agonists like semaglutide and tirzepatide appear safe when monitored by a doctor. Side effects can include GI issues and rarely, pancreatitis or gallbladder problems. Ongoing research is assessing risks of prolonged use.

7. Can I stop taking weight loss injections once I reach my goal weight?

Stopping the medication often leads to weight regain, as seen in clinical studies. Because obesity is a chronic condition, many people may need to stay on a maintenance dose or continue long-term use to keep weight off. Some may taper off with careful medical supervision and lifestyle support.

8. What’s the difference between Wegovy and Ozempic?

Both contain semaglutide, but Wegovy is FDA-approved for weight loss, while Ozempic is approved for type 2 diabetes. Wegovy is prescribed at a higher dose (2.4 mg weekly) compared to Ozempic (up to 2.0 mg). If you're taking it for weight loss, Wegovy is the official option.

9. Are there any natural alternatives to weight loss injections?

While no natural treatment matches the effectiveness of GLP-1 injections, dietary changes, increased protein intake, fiber-rich meals, intermittent fasting, and exercise are essential foundations. Some natural supplements (e.g., berberine, inositol) are being studied, but results are modest.

10. What’s the best injection for weight loss in 2025?

As of 2025, Zepbound (tirzepatide) leads in clinical effectiveness, with average weight loss reaching over 20% of body weight. Wegovy (semaglutide) is also highly effective, especially for those who may not tolerate tirzepatide. The best option depends on your health profile, side effect tolerance, and insurance coverage.