Kybella and lipodissolve are the same idea about ten years apart. What separates them is the history in between. Lipodissolve came first. It spread through medical spas, drew regulatory action, and never went through an approval process. Kybella is one molecule taken out of that mixture and put through the full drug pathway.
Lipodissolve began with a product that was never meant to be injected into fat. Lipostabil was a phosphatidylcholine preparation given into a vein. Phosphatidylcholine is called PC for short. Sodium deoxycholate, or DC, was added to keep the PC dissolved in water. The DC was a solubiliser, not an active drug. Practitioners began injecting the product under the skin instead. The practice picked up several names. Mesotherapy is the broad one. Injection lipolysis is the fat-specific one. Lipodissolve is the name for the PC-plus-DC version. The terms are used interchangeably.
Then a 2004 lab study turned the recipe inside out. It tested the PC product against sodium deoxycholate on its own. It also tested two lab detergents. All of them killed cells and broke open cell membranes. All of them damaged fat and muscle to a similar degree. The study concluded that sodium deoxycholate was the major active component. The inactive ingredient was the drug.
On 7 April 2010 the FDA issued seven warning letters over lipodissolve marketing. Six went to US medical spas and one to a Brazilian company running two websites. The claims named as unsupported included that the products were safe and worked for removing fat, and that they beat liposuction. The harms the agency said it had documented were permanent scarring, skin deformation and deep painful knots under the skin at injection sites.
One molecule was then taken through the pathway lipodissolve never entered. Man-made deoxycholic acid, with no PC in it, was developed as ATX-101. It was tested in four large phase 3 trials inside an 18-study programme. The FDA approved it on 29 April 2015 under application NDA 206333. That is the whole distinction. Lipodissolve is a practice. Kybella is a drug with an application number, an approval date and a label.
Developed as ATX-101 by Kythera, bought by Allergan, now distributed by AbbVie. Current label revision October 2024.
Also called injection lipolysis, and used more or less interchangeably with mesotherapy. There is no single lipodissolve recipe and no manufacturer standing behind one.
Once DC was named as the active detergent, the obvious move was clear. Develop that molecule alone, at a fixed strength, and take it through trials.
The DC in it was a solubiliser, listed as an inactive ingredient. That is the detail that eventually undid the original rationale.
The label's mechanism section reads, in full, that the drug "physically destroys the cell membrane causing lysis." A phase 1 study in 14 people took tissue samples, and the drug developer's own employees wrote it up. It showed fat-cell breakdown and inflammation on day 1. Macrophages were clearing debris by about day 7. By day 28 the inflammation had largely settled, with thickened septa and shrunken fat lobules.
Tissue samples taken after PC-DC injection have shown scarring, small abscesses and panniculitis. They have also shown fat death, with tiny calcium deposits and cysts.
The label adds that use outside the submental region "has not been established and is not recommended."
FDA's consumer page, content current as of December 2023, names lipodissolve among unapproved fat-dissolving injections. It says phosphatidylcholine and deoxycholate "pose a significant safety risk because they are unapproved." That is the agency's own wording.
Pooled across the two North American trials in 1,022 people: 68.2% versus 20.5% on placebo improved a grade on both the clinician and patient scales. Two grades: 16.0% versus 1.5%. On MRI, 43.3% versus 5.3% reached a 10% cut in submental fat volume. The longest peer-reviewed follow-up is 3 years. That study was limited to people who had already responded, and the sponsor funded and analysed it.
The largest submental trial enrolled 42 people. It called the improvement from either arm minimal. A split-body trial in 37 women found no real difference between the mixture and DC alone. The abdominal trial cited most often had 13 enrolled and 7 finishing.
Approval carried one specific post-marketing requirement: a safety study in people aged 65 to 75. The agency judged that voluntary reporting alone would not describe nerve injury and swallowing trouble well enough in that age group.
Seven letters went out on 7 April 2010, to six US medical spas and one Brazilian company. Reports the agency says it has received include permanent scars, serious infections, skin deformities, cysts and deep painful knots.
Beyond 30 days, 42% still had numbness and 20% still had swelling. In a real-world series of 165 people, 13.3% missed work in the week after the first session. That fell to 2.4-6.0% after later ones.
The professional body's list across mesotherapy and injection lipolysis is broader. It runs: bruising, hives, itching, swelling, firmness, pigment change, numbness, abscesses, skin ulcers, granulomas, nerve injury, atypical mycobacterial infection, panniculitis and hair loss.
The median number needed for a response in the trials was 3, and 59% of people went through all six.
Lipostabil was a PC preparation designed to go into a vein. The move that created lipodissolve was injecting it into the fat under the skin instead. That was off-label use of a product built for a different route and a different job. From there the practice spread. First in Europe and South America, then through US medical spas in the 2000s. It travelled under a rotating set of names. Mesotherapy covers the broad idea of injecting mixtures into the layer under the skin. Injection lipolysis is the fat-specific version. Lipodissolve is the consumer-facing name for the PC-DC recipe.
One part of the origin story needs care. The regulatory history of Lipostabil in Brazil and Europe is often summarised confidently online. That history could not be confirmed against a primary regulator document, so it is not asserted here. What is on the record is what the FDA did in the United States, and that is documented in full.
The whole case for lipodissolve was that PC was the active ingredient. The 2004 study found it was not.
The study compared the PC product with sodium deoxycholate on its own. It also compared both with the lab detergents Triton-X 100 and Empigen BB. It ran cell viability tests, membrane lysis tests, and injections into pig tissue. All of them caused large and similar damage. The conclusion was that the product "works primarily as a detergent causing nonspecific lysis of cell membranes." Sodium deoxycholate was the major active component. The same group followed up in 2005 with a small clinical series treating lipomas. It reported the same thing. DC, not PC, was the active ingredient.
Two randomised studies then tested that directly. A 2008 split-body trial in 37 women put the mixture on one side of the body and DC alone on the other. Each side had four treatments, eight weeks apart. Fat fell in 91.9% of them, with no real difference between the two sides. Side effects were stronger and slower to settle on the DC-only side. A 2009 trial split 42 people between one and the other under the chin. It reported no clear difference in results or side effects from adding PC.
That is why Kybella is pure man-made deoxycholic acid with no PC in it. The drug that got approved is, in effect, the part of lipodissolve that was doing the work, isolated and dosed.
On 7 April 2010 the FDA issued seven warning letters over the marketing of lipodissolve: Six went to US medical spas. They were Monarch Medspa in King of Prussia, Pennsylvania; Spa 35 in Boise, Idaho; Medical Cosmetic Enhancements in Chevy Chase, Maryland; Innovative Directions in Health in Edina, Minnesota; PURE Med Spa in Boca Raton, Florida; and All About You Med Spa in Madison, Indiana. The seventh went to a Brazilian company running the websites zipmed.net and mesoone.com.
The agency named several claims as unsupported. Those were that lipodissolve products were safe and worked for removing fat, that they beat liposuction, and that they could treat male breast enlargement, lipomas and surgical deformities. The harms the agency said it had documented were permanent scarring, skin deformation, and deep painful knots under the skin at injection sites. Janet Woodcock then led the FDA's drug centre. She said the agency was worried the companies were misleading consumers. She added that anyone thinking about the procedure should understand that "the products used are not approved by the FDA for fat removal."
Fifteen years later the agency's public position has not changed: Its consumer page on fat-dissolving injections, content current as of 20 December 2023, names lipodissolve among unapproved products. It names PC and DC as common ingredients that "pose a significant safety risk because they are unapproved." It lists reports of permanent scars, serious infections, skin deformities, cysts and deep, painful knots.
An earlier FDA statement on lipo-dissolve dated 2007 is cited in the plastic surgery literature. It can no longer be retrieved from FDA's own site. So it is best treated as something the literature reports, not as a document you can go and read.
The American Society of Plastic Surgeons published a policy statement on mesotherapy and injection lipolysis in 2019. It draws exactly the line this page is about.
On evidence: "There is increasing evidence for injection lipolysis, including level I evidence for DCA. There is lesser quality evidence available for PC therapy, which has been commonly used in Europe for decades. For other mesotherapy treatments, the data is even more limited."
On the state of the research: most uses have only low-level evidence. Most studies lack a proper control group. In the society's words, "information on the formulation of solutions, recommended dosages, and injection technique is not available. There are currently no recommendations for standardized treatment protocols."
On what to do about it: "Until more data is available, we cannot recommend routine clinical use of mesotherapy injections." The statement singles out deoxycholic acid for submental fat as the exception. It cautions members against using it for other purposes.
The statement also makes the legal point cleanly. Mixing PC and DC for injection makes a new drug that is not FDA-approved for any purpose. So, in its words, "its use would NOT be considered 'off-label' use." Injecting Kybella somewhere other than under the chin is off-label use of an approved drug. Injecting a compounded lipodissolve mixture is not the same category of act.
Ask what you are being injected with, by name and strength, and ask before the day: For an approved drug this is on the label and the vial. For a compounded mixture, only the prescriber and the pharmacy know it.
Say in advance if you take a blood thinner or an antiplatelet medicine, or have a bleeding disorder: Bruising affected 72% of people in the Kybella trials. The label says to use the drug with caution in those situations.
Say in advance if you have ever had trouble swallowing: People with current or past swallowing trouble were kept out of the Kybella trials, and the label says to avoid use in them.
Fullness under the chin is not always fat: The Kybella label tells the injector to check first for an enlarged thyroid and enlarged neck lymph nodes. It also says to think carefully before treating loose skin or prominent neck bands.
Neither should be injected into skin that is infected.
Trouble swallowing, or any trouble breathing
Fever or chills after an injection session
Redness spreading outward from an injection site hour by hour
Pus or discharge from an injection site
Trouble swallowing after deoxycholic acid injection usually comes from swelling rather than nerve damage. In the trials it settled by itself, with a median of 3 days. It still needs same-day assessment. Any trouble breathing is an emergency.
Your smile becomes uneven, or one side of your lower lip stops moving. This is the marginal mandibular nerve. It was reported in about 4% of people in the Kybella trials
Any facial muscle weakness appears, or numbness gets worse rather than better
An open sore, ulcer, or patch of dark, dead-looking skin appears at an injection site
A firm lump is still there more than a month after a session
A bald patch appears at an injection site. It is a labelled reaction, and the label says it may last
Swelling, redness or pain is increasing after day three instead of settling