Abdominal Fat Injections Explained: Fat Dissolving Jabs vs Weight Loss Injections

• Separates two treatments that share a name and nothing else
• States the UK licensing position on fat dissolving injections plainly
• Licensed injection sites and missed dose handling, taken from MHRA approved product information
• Online consultation with UK registered prescribers through a GPhC registered pharmacy

Ever wondered why someone can inject a weight loss medicine into their stomach without actually losing fat from that exact spot?

That is because there are two very different types of injections that can be described as “abdominal fat injections”. One is a cosmetic treatment injected into a specific area of fat with the aim of reducing fat cells locally. The other is a prescription weight management medicine injected under the skin of the abdomen, which works throughout the body after it is absorbed.

The difference matters. A cosmetic fat dissolving treatment is not the same as a licensed weight management medicine, and a weight loss injection does not target the fat underneath the needle.

Fat dissolving treatments, sometimes called injection lipolysis, are intended to work on a small area of fat. Some products contain deoxycholic acid. In the UK, deoxycholic acid has had a marketing authorisation for Belkyra, but that medicine is authorised for treating submental fat, meaning unwanted fat under the chin. That does not mean it is licensed for injecting abdominal fat.

Weight management medicines such as semaglutide and tirzepatide work differently. They are prescription only medicines used as part of a wider weight management plan. They affect appetite and other signals involved in food intake after they are absorbed into the body. They are not designed to break down fat only where the injection is given.

Key things to know

• Fat dissolving injections and weight loss injections are different treatments with different purposes, evidence and regulatory positions.
• Deoxycholic acid is not licensed in the UK as a treatment for reducing abdominal fat. A deoxycholic acid medicine called Belkyra has had a UK marketing authorisation for submental fat under the chin, which is a different use.
• Prescription weight management medicines such as semaglutide and tirzepatide are authorised medicines and should only be supplied following an appropriate clinical assessment.
• The abdomen is one of the approved injection sites for semaglutide and tirzepatide. The injection site does not determine where weight or body fat is lost.
• Injecting a medicine into the abdomen does not make it specifically target abdominal fat. The medicine is absorbed and acts throughout the body.
• Tirzepatide product information advises rotating injection sites with each dose. Semaglutide product information also allows the injection site to be changed.
• Injection site reactions can happen. In pooled type 2 diabetes trials, they occurred in 3.2% of people taking tirzepatide compared with 0.4% taking placebo.
• Whether a treatment is suitable depends on your health, medicines, medical history and the particular treatment being considered. Results also vary from person to person.

Two completely different injections

The easiest way to understand abdominal fat injections is to separate the two ideas completely.

The important point is that these are not two versions of the same treatment. They work differently and are intended for different purposes.

Fat dissolving injections for the stomach

What are they, and how are they meant to work?

Fat dissolving injections, sometimes called injection lipolysis, involve placing a substance directly into a localised area of fat. The aim is to damage or break down fat cells in that treated area.

One substance used in this type of treatment is deoxycholic acid. It is a bile acid that occurs naturally in the body and is involved in the digestion of fat. In Belkyra, deoxycholic acid is used to treat submental fat under the chin. Its UK authorisation does not cover abdominal fat.

You may also come across other substances or products marketed as fat dissolving injections. Their ingredients, evidence, regulatory status and intended uses can differ, so it is important not to assume that one product has the same evidence or authorisation as another.

Are fat dissolving injections licensed in the UK?

This needs a little more explanation than a simple yes or no.

Deoxycholic acid itself is not an unlicensed substance in every situation in the UK. Belkyra, which contains deoxycholic acid, has had a UK marketing authorisation as a prescription medicine for treating submental fat in adults. Its authorised use is specifically for fat under the chin, not for reducing abdominal fat.

So if a clinic offers a deoxycholic acid injection for abdominal fat, the important question is not simply whether deoxycholic acid is a licensed substance. You should ask whether the specific product is authorised for the procedure being offered.

A medicine's marketing authorisation covers its approved use and comes with product information explaining how it should be used, along with its known risks and side effects.

Do fat dissolving injections work on the stomach?

This is where it is worth being cautious about marketing claims.

A local fat dissolving injection is designed to treat a specific area. The abdomen, however, can contain both subcutaneous fat, which sits underneath the skin, and deeper visceral fat around the internal organs.

An injection placed under the skin cannot simply be expected to reach visceral fat around the organs. Visceral fat is linked with health risks such as high blood pressure, type 2 diabetes and cardiovascular problems, which is one reason abdominal fat is considered in overall health assessments.

A cosmetic injection may therefore address a local appearance concern without addressing deeper abdominal fat or the wider health factors linked with excess weight.

It also will not automatically address loose skin, which can sometimes be part of what someone notices around their stomach.

Before and after photographs: what to watch for

Before and after photographs can look convincing, but they do not tell you everything about a treatment.

If you are looking at photographs, consider four things:

1. Lighting, posture and angle. The appearance of the stomach can change noticeably depending on how someone is standing and how the photograph is taken.
2. Time between photographs. If several weeks or months have passed, other changes in weight or lifestyle may also have affected the result.
3. What else changed. A photograph does not tell you whether the person also changed their diet, activity levels or other treatments.
4. Whether measurements are provided. Measurements taken in a consistent way can provide more useful information than photographs alone.

A photograph does not prove that a treatment works or does not work. It is simply one piece of information, so it is sensible to look at the evidence, the product being used and the practitioner's qualifications as well.

Are fat dissolving injections safe?

Any injection carries risks, and the risks depend on the product, where it is injected and how the procedure is performed.

For cosmetic fat dissolving procedures, possible problems can include swelling, bruising, pain, tenderness, lumps or nodules, uneven results and infection. Incorrect injection technique can also damage nearby tissues or structures.

The risks can be particularly important when treating a larger area such as the abdomen because more injection points may be needed. This does not mean that a complication will happen, but it is worth understanding what could happen before agreeing to treatment.

If you have a health condition such as high blood pressure, heart disease, diabetes or another condition that could affect your treatment, tell the healthcare professional or practitioner about it before having an injection.

What the regulation actually allows

The regulation of non surgical cosmetic procedures in England is changing, but the new system is not yet fully in force.

The government has acknowledged that the current system does not provide consistent national standards for qualifications, training and infection control across the non surgical cosmetics sector. In August 2025, the government confirmed plans to introduce local authority licensing for lower risk procedures and stronger restrictions for procedures considered to carry higher risks.

This means it is important to check who is carrying out a cosmetic injection, what product they are using, whether the product is authorised for the intended use and what arrangements are in place if something goes wrong.

Weight loss injections given in the stomach

Where do you inject weight loss injections in the abdomen?

The abdomen is one of the approved injection sites for semaglutide and tirzepatide.

Current UK product information states that Wegovy, which contains semaglutide, is injected under the skin of the abdomen, thigh or upper arm. The injection site can be changed.

Mounjaro, which contains tirzepatide, is also injected under the skin. Its product information allows the abdomen and thigh, with the back of the upper arm used when someone else gives the injection. Injection sites should be rotated with each dose.

Both medicines can be taken at any time of day, with or without food.

Do weight loss injections target belly fat?

No. Where you inject the medicine does not decide where you lose body fat.

The medicine is injected under the skin and then absorbed into the body. Semaglutide and tirzepatide affect systems involved in appetite and food intake rather than acting only on the fat underneath the injection site.

That is why the abdomen, thigh and upper arm can all be used as injection sites. The site is chosen for safe and practical administration, not because it tells the medicine where to reduce fat.

Why the injection site does not decide where the fat goes

Your body does not lose fat in a perfectly predictable order. Where changes are noticed first can vary between people and is influenced by factors such as genetics, hormones, overall energy balance and body composition.

So if you inject into your abdomen, you should not expect the fat around your stomach to disappear first.

There is also an important health distinction between the fat you can pinch under the skin and visceral fat stored deeper inside the abdomen. Carrying more fat around the waist is associated with a higher risk of several health conditions, including type 2 diabetes and cardiovascular disease.

Our guide to medical weight loss explains more about how medical weight management works and how treatment suitability is assessed.

Rotating sites, and what to do about a missed dose

If you use a weight management injection, follow the instructions for your specific medicine. The advice is not exactly the same for semaglutide and tirzepatide.

Tirzepatide product information says injection sites should be rotated with each dose. Semaglutide product information allows the injection site to be changed between doses.

The missed dose instructions are also different:

These instructions come from the current product information for the medicines.

Never take two doses to make up for a missed dose. If you have missed more than one dose, speak to your prescriber before restarting. The product information for semaglutide specifically notes that a lower starting dose may need to be considered after several missed doses.

Injection site lumps on the stomach

Why lumps happen

A small lump, redness or itching where you injected can be an injection site reaction. These reactions are recognised with weight management injections and are often mild.

For tirzepatide, injection site reactions occurred in 3.2% of people taking tirzepatide compared with 0.4% taking placebo in pooled type 2 diabetes trials. In the reported trials, most reactions were mild.

A lump can also be related to repeatedly using the same small area, a bruise or a small amount of bleeding under the skin.

This is one reason it is important to rotate injection sites and follow the instructions that come with your pen.

When a lump needs urgent attention

Contact a healthcare professional promptly if you notice:

• Redness, heat or pain that is getting worse rather than settling
• Pus or discharge from the injection site
• Fever, chills or feeling generally unwell along with the injection site problem
• A lump that continues to grow or does not start settling
• Swelling of the face, lips or throat, or difficulty breathing. This can be a medical emergency.
• Severe or persistent abdominal pain, particularly if it spreads to your back. This needs urgent medical assessment.

If you are unsure whether a reaction is normal, it is better to ask your pharmacist, prescriber or GP rather than trying to diagnose the lump yourself.

Non surgical injections for abdominal fat: which route suits which problem

There is no single injection that is right for every person with abdominal fat.

If your concern is a small, localised cosmetic area, you may be considering a local cosmetic procedure. The suitability of that treatment depends on the product, the area being treated, your health and the practitioner's assessment.

If your concern is overall weight, health risks linked with excess weight or difficulty managing your weight, a weight management assessment may be more appropriate. Prescription medicines such as semaglutide and tirzepatide are used as part of medical weight management for people who meet the relevant criteria.

If you are not sure which category applies to you, that is exactly what an assessment is there to help with. You can read about the weight loss treatments available and how eligibility is assessed.

Buying safely, and the counterfeit problem

If you are considering a prescription weight management injection, where you buy it matters.

The MHRA has warned people about fake and illegally supplied weight loss pens. In 2023, it reported cases where people who had used potentially fake pens needed hospital treatment, including for hypoglycaemic shock and coma. The MHRA said some of the pens may have contained insulin rather than the medicine stated on the label.

The MHRA continued to warn in 2025 about buying weight loss medicines from unregulated websites and social media, noting that illegally supplied products may be fake, contaminated, incorrectly dosed or contain ingredients that are not listed on the packaging.

Before buying an injectable medicine, check that:

• The pharmacy is registered with the General Pharmaceutical Council if it is operating as a pharmacy in Great Britain
• You are asked relevant medical questions and your suitability is properly assessed
• You know which medicine you are being prescribed
• You receive information about how to use the medicine and what to do if you have problems
• The medicine comes through a legitimate supply route
• You are not being encouraged to buy a prescription medicine through social media or an informal messaging service

A proper clinical assessment should be about more than simply taking payment and sending out a pen.

Getting assessed properly

A good weight management consultation should look at you as a whole person, not just a number on the scales.

Depending on your circumstances, the prescriber may ask about your height and weight, weight history, existing medical conditions, medicines and supplements, family medical history, pregnancy plans and other factors that could affect treatment.

It is also important to mention any previous problems with your stomach, pancreas or gallbladder, as well as any other conditions or medicines you are taking.

If you would rather avoid injections, there are also oral medicines used for weight management in some circumstances. You can read more about oral GLP-1 weight loss tablets.

These medicines should only be used under the supervision of an appropriately qualified prescriber. Whether a particular treatment is suitable for you should be decided after an individual clinical assessment.

Medical Disclaimer

This article is for general information and does not replace personal medical advice. Prescription weight management medicines should only be used under the supervision of an appropriately qualified prescriber, and treatment suitability depends on an individual clinical assessment. Results vary between individuals.

Always read the patient information leaflet and the instructions supplied with your medicine. If you develop a spreading or increasingly painful injection site, fever, difficulty breathing or severe abdominal pain, seek prompt medical advice.