What Are Fat Dissolving Injections (Meso Fat)? A Guide

What fat dissolving injections are

Fat dissolving injections are placed in the fat layer under the skin to break down fat cells near the injection site, without surgery. [1] The US FDA calls the method injection lipolysis, and you may also see it written as lipolysis injections. [1] In Thailand it is sold as meso fat (เมโสแฟต), ฉีดแฟต or ฉีดสลายไขมัน, which all describe the same kind of injection. [1][3]

The goal is to reduce fat that has built up in one spot, not to add fat. [1] It is not a weight-loss method either. One review describes it as a non-surgical option for localized fat, not a treatment for obesity. [2]

Ingredients used in fat dissolving injections

The US FDA says the substances found most often are phosphatidylcholine (PC) and sodium deoxycholate (DC), used alone or together. It calls injections that use both PCDC. [1] In a 2018 review, PC is a phospholipid fat taken from soy lecithin, and DC is a bile salt that works like a detergent and helps PC dissolve. [2]

The review's authors explain that the two substances probably destroy fat cells, and the body then slowly clears away the debris. The exact mechanism is still being studied. [2]

Thai FDA (อย.) once warned about steroids being injected to dissolve fat, which counts as using them for the wrong purpose. [3] So ask to see the full ingredient label of the exact product before you decide.

Do fat dissolving injections work? What the evidence shows

The US FDA notes that sellers claim the injections reduce fat under the chin and in the back, thighs, upper arms and abdomen. [1] But the FDA has not evaluated either the safety or the effectiveness of the ingredients. [1]

The review cited here comes from a single institution in India and covers 1,269 patients over 14 years. Its authors conclude the injections worked for localized fat. [2] However, it is a retrospective assessment, and its results table shows that the number of satisfied patients varied widely by area, with very few satisfied in some areas. [2]

The authors also say liposuction is the gold standard for reducing fat under the skin, and fat dissolving injections are only a supplementary option, not a replacement for liposuction. [2]

In 2018, Thai FDA (อย.) said no standard had ever been certified and there was no clear medical research showing that the injections dissolve fat. [3] So do not treat "visible results" in an advertisement as a conclusion.

Who fat dissolving injections suit

The review's authors describe the suitable patient as someone with a small amount of excess fat in one spot, where the fat can be pinched and has an even texture, and who wants a non-surgical option. [2] Another group is people with fat left over after liposuction. [2]

If you want to lose weight across your whole body, the review does not treat fat dissolving injections as a treatment for obesity. [2] Thai FDA (อย.) advises exercise and diet control as the safe route to a firmer shape. [3]

Ask a doctor to assess what kind of fat you have, and whether this method suits you or should be compared with other options.

Who should avoid fat dissolving injections

The authors list the contraindications below. The list comes from a single review of a PC plus DC formula, so let a doctor assess it against the formula used and your own history.

Severe allergic reaction is a risk that Thai FDA (อย.) warned can be life-threatening. [3] Always tell the doctor about your allergies and any medicines you take.

• Allergy to eggs or soy [2]
• Infected skin or a skin problem in the area to be injected [2]
• Currently taking blood thinners [2]
• A weakened immune system [2]
• Hormone imbalance, such as an underactive thyroid or polycystic ovary syndrome (PCOS) [2]
• Pregnancy or breastfeeding [2]
• Unrealistic expectations, which the authors count as a relative contraindication [2]

Common side effects after the injection

In the 2018 review, almost every patient felt a burning sensation in the first few hours, local swelling lasted about 24-48 hours, and the skin stayed red for 1-2 days. [2]

Lumps under the skin occurred in more than half of the patients in that study. The authors explain that they come from inflammation and fibrosis (scar-like tissue) and cleared in about 3-4 weeks. [2]

Some patients had whole-body symptoms such as diarrhea, tiredness, headache or nausea, which usually began within 24 hours and cleared in 2-3 days. [2] These figures come from one institution and one formula, so your own experience may differ. [2]

More detail on how many days swelling lasts and what to avoid after the injection is in the other articles in this series.

Are fat dissolving injections safe? Risks to know

The US FDA says the ingredients are a significant safety risk because they are not approved, and it cites reports of permanent scarring, severe infection, skin deformities, cysts, and hard, deeply painful lumps. [1] The number of injection sites, needle placement and poor technique raise the chance of scarring, infection and serious complications. [1]

In the 2018 review, 15 patients had severe pain after the substance went into muscle. The authors say none occurred again after they switched to a technique of lifting the skin. [2]

In 2018, Thai FDA (อย.) said these injections risk a severe, even life-threatening allergic reaction, and may leave the skin wavy because fat is dissolved unevenly. [3]

The US FDA also notes reports of injections given at clinics or medical spas by people who may not hold the right license, and of some people buying the substances online and injecting themselves. [1]

Are fat dissolving injections registered or approved?

In a statement dated June 7, 2018, the Secretary-General of Thai FDA (อย.) said the agency had never registered any fat dissolving injection drug product, and that such products do not count as cosmetics. [3] A Deputy Secretary-General made a similar statement in 2015 about fat-dissolving injections for the abdomen. [5]

That information dates from 2018 and 2015. Before you decide, check the latest status of the exact product with Thai FDA (อย.) and ask the clinic for its Thai registration documents.

In the United States, the US FDA stated as of December 2023 that the PC and DC used in fat dissolving injections are not approved. The only approved fat dissolving injection is deoxycholic acid (brand name Kybella) for fat under the chin in adults. [1] Its April 2015 label says safety and effectiveness for injection into fat outside the area under the chin have not been established, and it is not recommended. [4]

That approval covers one drug for one area. It does not cover other formulas or other areas. [1][4]

Who should inject, and what to ask your doctor

Thai FDA (อย.) says the person injecting must be a doctor. [3] The US FDA advises against buying these substances online and against injecting yourself, because they may not work and may cause infection or permanent scarring. [1]

Amounts, number of sites and the treatment plan are for the assessing doctor to set, so this article does not give them. Consider bringing these questions to your doctor.

If you have side effects after an injection, the US FDA advises telling your health care provider. [1] Thai FDA (อย.) advises seeing a specialist doctor promptly. [3]

• What ingredients does the product contain? Can I see the label and the Thai registration documents? [3]
• Is the fat in my area suited to this method, or should I compare it with other options such as liposuction? [2]
• Do I have an egg or soy allergy, or take medicines that affect blood clotting? [2]
• If I get lumps, an infection or uneven skin after the injection, whom do I contact and how is it treated? [1]

How fat dissolving injections differ from liposuction

The review's authors explain that fat dissolving injections are less invasive and have a shorter recovery, but they are not a replacement for liposuction. [2] Both methods target fat under the skin (subcutaneous fat). [1][2] The table below covers only points the sources discuss.

If you are not sure whether a square or full lower face comes from fat or from muscle, see the article in this series on fat injections versus Botox for jawline slimming.

Which areas of the body the injections are used on

In the 2018 review, injections were given under the chin, on the jowls beside the jaw, flanks, abdomen, upper arms, thighs and knees. [2] Patient satisfaction varied by area, [2] so ask a doctor to assess each area separately.

Other articles in this series cover each topic separately.

• Slim or square face: fat injections versus Botox for jawline slimming
• Abdomen and upper arms: fat injections for the abdomen and upper arms
• Under the chin: fat injections for a double chin
• Afterward: how many days swelling lasts, and what to avoid after the injection