Weight loss injections – what they are and how to get them

Weight loss injections, like Wegovy and Ozempic, continue to make waves as an effective weight loss management solution. They suppress your appetite and reduce hunger. 

To get weight loss injections, you need to make an appointment with your physician in-office or online telehealth to get an assessment and prescription.

What are weight loss injections?

Weight loss injections are a way to take medications that help with weight loss. They come as pre-filled injection pens that you administer yourself. Your physician instructs you on how to properly use them at home. You start with a small dosage, which gradually increases until you reach a maintenance dose.

These weight loss injections help you lose weight by reducing your appetite. The most popular, Wegovy and Ozempic are branded versions of semaglutide that mimics a natural hormone called glucagon-like peptide-1 (GLP-1) and are known as GLP-1 agonists. 

GLP-1 lowers blood sugar, controls your hunger, slows down your digestion, and delays the stomach-emptying process. When you feel full longer, you eat less. Over time, your reduced appetite and calorie intake result in fat loss.

Weight loss injections are not stand-alone solutions to weight loss and are prescribed as part of a medical weight loss program alongside a healthy lifestyle consisting of a balanced diet and regular exercise. 

What are the available weight loss injections?

There are a handful of weight loss injections approved or used off-label (used for a purpose other than what the FDA has approved them for) for weight loss in the U.S. today. There are also several injectable weight loss medications currently undergoing clinical studies, some in the U.S., some overseas. If the studies work, the FDA may or may not approve the medications. 

FDA-approved injectable medications for weight loss include Wegovy, Saxenda, and Zepbound. 

Wegovy (semaglutide)

Wegovy is approved for people with a body mass index (BMI) of 30 or are overweight (have a BMI of 27 or higher) and have a weight-related health problem, such as high blood pressure or type 2 diabetes.

How it works: Wegovy works by mimicking GLP-1 to regulate your appetite and letting you eat less. Along with diet and exercise, you lose weight. 

When approved: The FDA approved Wegovy in June 2021.

How long it takes: Weight loss may begin within the first 4 weeks of treatment with full effects seen after several months or longer.

How it’s administered: Wegovy comes in a pen prefilled with 4 doses, which is a month’s supply. You inject it under the skin once a week. The initial dose is 0.25 mg, which is increased every 4 weeks to a maintenance dose of 1.7 mg or 2.4 mg a week.

Zepbound (tirzepatide) 

Zepbound is the newest entrant to the weight loss injection market. Like Wegovy, it’s approved for people with a BMI of 30 or a BMI of 27 or higher with a weight-related health problem.

How it works: Zepbound works by targeting gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) hormones to reduce feelings of hunger and decrease food intake. You feel fuller faster and longer.

When approved: The FDA approved Zepbound in November 2023.

How long it takes to see results: Many people begin to lose weight within a few weeks, but weight loss can continue for up to a year.

How it’s administered: You inject it under the skin once a week. The initial dose is 2.5 mg for four weeks and may increase to 5 mg once per week.

Saxenda (liraglutide)

Saxenda is approved for use in people with a BMI of 27 or higher with weight-related medical problems or a BMI of 30 or higher without a weight-related medical problem. It’s also approved for use in children aged 12 to 17 years with a body weight above 132 pounds and obesity. It’s intended to be used with diet and exercise. 

How it works: Saxenda works by mimicking GLP-1 to regulate feelings of hunger. It lowers appetite and slows gastric emptying, making you feel full for longer and helping you decrease your caloric intake. 

When approved: The FDA approved Saxenda in December 2014.

How long it takes: Some people start losing weight in the first 2 to 4 weeks after starting treatment and continue losing weight for 9 to 12 months.

How it’s administered: Saxenda is injected under the skin once a day, independent of meals. The starting dose is 0.6 mg per day for 1 week, which can then be increased by 0.6 mg each week until reaching a full maintenance dose of 3 mg.

Ozempic (semaglutide)

Ozempic is similar, but not identical to or interchangeable with Wegovy. It’s approved for people with type 2 diabetes and used off-label for weight loss. Learn more about Ozempic vs Wegovy.

How it works: Ozempic is a GLP-1 agonist and helps improve blood sugar and may reduce the risk of major cardiovascular events, such as stroke, heart attack, or death, in type 2 diabetics with cardiovascular disease. It may also help with weight loss.

When approved: The FDA approved Ozempic as a type 2 diabetes medication for adults in 2012.

How long it takes: It takes a few weeks to start losing weight.

How it’s administered: Ozempic is injected once a week on the same day, at any time of the day. It comes in a pen prefilled with 4 doses, which is a month’s supply. It’s injected under the skin once a week. The initial dose is 0.25 mg, which is increased every 4 weeks to a maintenance dose of 1 mg or 2 mg a week.

Mounjaro (tirzepatide) 

Mounjaro is the same medication as Zepbound sold under a different brand name and approved for use in adults with type 2 diabetes to lower average blood sugar levels.

How it works: Mounjaro mimics the actions of GIP and GLP-1 to lower average blood sugar levels. It may also decrease how much food you eat.

When approved:  The FDA approved Mounjaro in May 2022. 

How long it takes: Many people begin to lose weight within a few weeks, but full effects can take a year.

How it’s administered: Mounjaro is injected under the skin, once a week, at any time of the day. The initial dosage is 2.5 mg, which is increased to 5 mg after 4 weeks. 

Botulinum toxin (gastric botox)

Botox is a toxin that, when injected, paralyzes a muscle to prevent it from moving for a limited time. It’s commonly used to paralyze facial muscles to temporarily reduce wrinkles, but also aids weight loss. 

How it works: Gastric botox temporarily relaxes the stomach walls to slow down stomach emptying. It helps make you feel full longer and reduces your appetite.

When approved: Botox was approved by the FDA for certain muscle disorders and cosmetic use for wrinkle treatment in April 2022. It’s only used off-label for weight loss.

How long it takes:  Some people start losing weight in the first few weeks and continue losing for 4 to 6 months.

How it’s administered: Botox injections are done as an outpatient procedure where a doctor uses an endoscope (a tube with a syringe) inserted into the stomach through the mouth to inject the stomach muscle.

Retatrutide

Retatrutide is being studied as a treatment of type 2 diabetes obstructive sleep apnea, osteoarthritis, obesity, and non-alcoholic fatty liver disease. It’s not yet approved or available.

How it works: Retatrutide stimulates GIP, GLP-1, and glucagon receptors that are involved in controlling hunger and satiety. It may help regulate your blood sugar levels and make you feel fuller for longer after eating.

When approved: Retatrutide is under clinical development by Eli Lilly and Company and is currently in the National Institute of Health (NIH) phase III clinical trials for obesity.

How long it takes: Clinical trial participants have experienced an average of 24% body weight reduction over 48 weeks.

How it’s administered: Retatrutide is injected once weekly. The initial dosage is 0.5 mg and can be increased to 1 mg, 2 mg, or 4 mg after 4 weeks. The maximum dose is 12 mg weekly.

CagriSema

CagriSema is being studied as a treatment of type 2 diabetes to help with weight loss. It’s not yet approved or available.

How it works: CagriSema is a combination of semaglutide and a compound called cagrilintide. Cagrilintide works by stimulating a hormone called amylina, which is produced by the pancreas and makes people feel full after eating a meal.

When approved: Novo Nordisk is running phase III clinical trials of CagriSema. 

How long it takes: Clinical trial of CagriSema on participants experienced a 15% in body weight reduction at week 32. It appears to lower blood sugar and lead to more weight loss than semaglutide alone.

How it’s administered: CagriSema is given via a once-weekly injection. Dosage is escalated every 4 weeks from 0.25 to 0.5 to 1.0 to 1.7 mg to a maintenance dose of 2.4 mg at 16 weeks. 

Ecnoglutide

Ecnoglutide is in development as a treatment for type 2 diabetes and obesity. It’s not yet approved or available.

How it works: Ecnoglutide works as a glucagon-like peptide-1 (GLP-1) agonist.

When approved:  Ecnoglutide is under clinical development by Sciwind Biosciences. US Sciwind is headquartered in Hangzhou, China. Ecnoglutide is currently being evaluated in phase III clinical trials.

How long it takes: Ecnoglutide is still being studied, but research participants lost up to 15% of their initial body weight after about 6 months.

How it’s administered: It’s injected under the skin once weekly.

Mazdutide

Mazdutide is being studied as a treatment for obesity. It’s not yet approved or available.

How it works: Mazdutide is a GLP-1 agonist that mimics glucagon, a hormone involved in regulating appetite.

When approved: China-based phase III studies are ongoing until 2025.

How long it takes to see results: Trial participants lost an average of 15% of their body weight in 24 weeks.

How it’s administered: Mazdutide is injected under the skin once a week.

Survodutide

Survodutide is being studied as a treatment for obesity and weight loss. It’s not yet approved or available.

How it works: Survodutide stimulates GLP-1 receptors that inhibit appetite and improve energy expenditure.

When approved: Boehringer Ingelheim and Zealand Pharma A/S are running phase III clinical trials in Europe for Survodutide through January 2026.

How long it takes: Trial participants have had up to  19% percent weight loss after 46 weeks of treatment.

How it’s administered: Survodutide is injected under the skin once a week.

Bimagrumab

Bimagrumab is being studied as a treatment for obesity and weight loss. It’s not yet approved or available.

How it works: Bimagrumab is an antibody that blocks activin type 2 receptors to help stimulate weight loss and aid lean muscle growth. 

When approved: The FDA gave a breakthrough therapy designation for bimagrumab in August 2013 for use in sporadic inclusion body myositis. It’s currently in phase II clinical trials as a treatment for weight loss until June 2025. 

How long it takes: Studies demonstrated up to 14.6% weight loss after 24 weeks of treatment.

How it’s administered: Bimagrumab is given as an infusion into a vein once a month.

Do weight loss shots work? 

Clinical studies of all the leading weight loss injections show that these medications do work.

According to a weight loss medication study by the National Institute of Diabetes and Digestive and Kidney Diseases on prescription medications, those who took weight loss injections lost an average of 5 to 10% of their body weight over a 6- to 12-month period. 

A New England Journal of Medicine study of 2,000 overweight or obese adults, compared participants who used semaglutide to complement a diet and exercise program with people who made the same lifestyle changes without using medication. After 68 weeks, half of the participants using semaglutide lost 35 pounds or about 15% of their body weight, and almost a third lost 20%. Those who didn’t take the drug lost about only 6 pounds or 2.4% of their weight.

In clinical trial results for Wegovy, participants lost an average of 14.9% of their body weight over 68 weeks. 

In clinical studies for Ozempic as a type 2 diabetes treatment, participants lost up to 14 pounds over 40 weeks. 

In Saxenda clinical trials for weight loss, participants lost an average of 9.2% of their body weight over 56 weeks.

What are the best weight loss injections?

The only FDA-approved weight loss injections are Wegovy, Saxenda, and Zepbound. Based on current studies, Wegovy and Zepbound show optimal results.

A 2022 study found that Wegovy produced the best weight loss results for a weight loss drug compared to a placebo or other diabetes medications. In the same study, people lost more weight with Wegovy than with Saxenda.

In the study, Wegovy lowered the risk of death from heart attack in diabetic patients who are overweight or obese. Rates of nonfatal heart attack and nonfatal stroke also decreased.

Although the comparison of the two drugs was indirect, another 2022 study found that a 5 mg dose of tirzepatide (Zepbound) was as effective for weight loss as the 2 mg dose of semaglutide, and the higher doses of tirzepatide (10 and 15 mg) were even more effective. 

Although the effectiveness of medications is one consideration, cost, and availability are other factors when deciding between brands.

What do shots for weight loss cost?

Weight loss shots can be pricey. Here’s a rundown of basic list prices.

Wegovy: $1,349.02 per package or a month’s supply

Zepbound: $1,059.87 per package or a month’s supply

Saxenda:  $1,349.02 a month

Ozempic: $935.77 a month

Gastric botox:  pricing varies by provider.

Some insurers may cover weight loss medications used for approved individuals. Other insurers cover it only if you meet certain requirements, and others don’t cover it at all. Drugs used off-label are only rarely covered by insurance.

Consult with your insurer to determine if weight loss injections are covered. You can also find available savings programs offered by drug manufacturers. GoodRx and other similar platforms can also help you find discounted prescriptions. Learn how to save on Ozempic and how to save on Wegovy.

What are the side effects of weight loss medications?

Overall weight loss pills are safe but can have side effects. Common side effects of weight loss medications are mostly gastrointestinal discomfort. These side effects are only temporary and may diminish over time. 

You may have the following side effects on Wegovy:

• Nausea
• Diarrhea
• Vomiting
• Constipation
• Abdominal pain
• Headache
• Fatigue
• Upset stomach
• Dizziness
• Feeling bloated 
• Belching
• Gas
• Stomach flu
• Heartburn
• Runny nose
• Sore throat

 Side effects of Saxenda can include:

• Nausea
• Diarrhea
• Constipation
• Vomiting
• Injection site reaction
• Low blood sugar (hypoglycemia)
• Headache
• Upset stomach (dyspepsia)
• Fatigue
• Dizziness
•  Stomach pain
• Change in enzyme levels in your blood
• Fever
• Gastroenteritis 

Side effects of Zepbound may include: 

• Nausea
• Diarrhea
• Vomiting 
• Constipation
• Abdominal pain
• Indigestion
• Injection site reactions
• Fatigue
• Allergic reactions
• Belching
• Hair loss
• Heartburn

More serious side effects can occur with these and any medication. Before taking medication, talk with your doctor and pharmacist about what to expect and what to watch out for. 

Find out more about weight loss injections with Klarity

If you’re struggling to lose weight, consult with a healthcare professional to develop a weight loss plan and decide if a medication-managed approach to weight loss is right for you. Your provider can get you a prescription and work with you throughout your weight loss journey.

The Klarity platform can connect you with private healthcare professionals, including licensed, independent registered nurses, physician assistants, and therapists – both online and offline – to manage your health and medications. Get started and find a licensed weight loss professional today.