Published 20 October 2026 · Reviewed by Dr Sin Yong
Deoxycholic acid is a naturally occurring bile acid that, in a synthetic injectable form, breaks open the membrane of fat cells so the body clears them. It is the active ingredient of the prescription medicine approved in the United States in 2015 as Kybella (ATX-101; Belkyra elsewhere) for fullness under the chin. It is the medicine behind the phrase fat dissolving injections, and it is not the same as mesotherapy.
Deoxycholic acid is worth knowing by name, because it separates a registered prescription medicine from the many products that borrow the phrase fat dissolving. It is a bile acid that acts like a detergent on fat-cell membranes, and its approved use is fullness under the chin. Phosphatidylcholine cocktails, Aqualyx and Lemon Bottle differ from it in composition, regulation and evidence.
What is deoxycholic acid?
Deoxycholic acid is one of the bile acids. The liver makes cholic acid, bacteria in the gut convert part of it into deoxycholic acid, and both circulate to emulsify dietary fat so it can be absorbed. The molecule is, in effect, a biological detergent.
The aesthetic use takes that property out of the gut and puts it into a fat pocket. A synthetic, purified deoxycholic acid is prepared as a sterile solution and injected in small volumes across a grid in the subcutaneous fat. There it inserts into the lipid membrane of the fat cell and breaks it. The cell dies, macrophages clear the released fat, and fibroblasts lay down a little collagen in the treated zone as it heals. The swelling that follows is this clearance in progress.
The mechanism explains both the appeal and the limits. It needs no device and can be dosed by injection points, but it is not selective: it damages whatever membrane it reaches, so depth, spacing and no-go zones decide its safety, and it does nothing to the skin above the pocket.
Names you will see
ATX-101: the development code used in the phase 3 trials (REFINE-1 and REFINE-2).
Kybella: the US brand name after FDA approval in 2015.
Belkyra: the brand name in Canada, Australia and parts of Europe.
Sodium deoxycholate: the salt form, which is the component used in older compounded lipolysis mixtures and in some CE-marked European products.
What is deoxycholic acid approved for?
The US prescribing information approves it for improvement in the appearance of moderate to severe convexity or fullness associated with submental fat in adults. The same document states that safety and effectiveness for fat outside the submental region have not been established. Every other site, including the jowl, the bra-line and the abdomen, is off-label.
The label also carries the two warnings that shape how it is used: injury to the marginal mandibular nerve, which can produce an asymmetric smile or lower-lip weakness, and difficulty swallowing, which can be made worse in people who already have it. The commonest reactions listed from the pooled trials are injection-site swelling, haematoma, pain, numbness, redness and firmness. Skin ulceration and injury have been reported where the medicine was placed too superficially.
The registration trials are summarised on the fat dissolving injections page, the owner page for the treatment on this site.
“Fat dissolving is a category, not a medicine. Before I discuss it with anyone I want to know which molecule, which registration, and which part of their chin is actually fat.”
Dr Sin YongOn Deoxycholic acid
Where deoxycholic acid matters on this site
The term appears wherever a small, pinchable fat pocket is being separated from the other things that produce the same profile.
Illustrative image — not a patient.
Double chin treatment: submental fullness can be fat, lax skin, platysma position or a short chin. Deoxycholic acid addresses the first and nothing else, which is why the page ranks the four causes before any method.
Jowl fat versus sagging: a fat-dominant jowl is a discrete pad; a laxity-dominant jowl is descended tissue. An injection that dissolves fat helps one and worsens the other.
Dr Sin Yong, an aesthetic physician on Orchard Road, Singapore, examines the pocket in person, with a pinch and tilt test and, where earlier filler is involved, ultrasound mapping, before any fat-directed option is named. Availability of a registered product is confirmed at consultation rather than assumed.
Lookalikes: phosphatidylcholine, Aqualyx and Lemon Bottle
Several products are sold under the same banner of fat dissolving, and they are not interchangeable.
Product or term
What it is
How it differs
Deoxycholic acid injection (the registered medicine)
Registered medicine with phase 3 trials and an approved indication under the chin
Phosphatidylcholine and deoxycholate (mesotherapy, lipodissolve)
Compounded mixtures of a soy-derived phospholipid with sodium deoxycholate as the solubiliser, often with other additives
No standard formulation; the deoxycholate is the active agent. Mesotherapy is no longer permitted in Singapore outside an approved clinical trial
Aqualyx
A deoxycholate-based buffered gel solution, CE-marked in Europe as a class III medical device rather than registered as a medicine
Device route rather than drug route; evidence is mostly small series and case reports
Lemon Bottle
Marketed as a blend of riboflavin, bromelain and lecithin
Contains no deoxycholic acid; classified in Switzerland as an unauthorised medicinal product in 2024, and sold in the UK as a cosmetic; no peer-reviewed efficacy data
The practical test is to ask what is in the syringe, whether it is registered with HSA, and what the evidence is for that product rather than the category. The Lemon Bottle and Aqualyx article goes through the last two in detail.
Your next step
1. MessageWhatsApp +65 8023 7170 with what is bothering you. A reply comes from the clinic, not a bot.
2. AssessmentDr Sin Yong examines you himself on Orchard Road, with ultrasound where earlier filler is involved.
3. A plan in writingWhat he would do, what he would not, the fee factors, and the option of no treatment.
Every treatment is performed by Dr Sin Yong personally. Singapore Medical Council registered · invited to share his clinical expertise internationally for CLASSYS, DEKA, Fotona, Hironic and Ilooda.
Deoxycholic acid injection is a prescription medicine, so in Singapore it can be supplied and injected by a registered doctor when a product registered with HSA is available. Availability has varied over the years and is confirmed at consultation, not assumed from a web page. Products bought online or injected outside a clinic fall outside both the product and the practitioner rules.
No. Mesotherapy means multiple shallow injections of compounded cocktails, usually phosphatidylcholine with sodium deoxycholate and other agents, with no standard formulation. Deoxycholic acid injection is a single registered medicine with a defined concentration, indication and technique. In Singapore mesotherapy is no longer permitted outside an approved clinical trial; a registered single-agent medicine is a different question.
The approved site is under the chin, where the injection grid, depth and no-go zones were worked out in the registration trials. Use on the jowl, bra-line, inner knee, arm or abdomen is off-label, with little published evidence, and body pockets need volumes of medicine that bring more swelling than most people accept. For a body pocket, energy-based methods are usually considered first.
No. It acts on fat cells, not on the dermis. A small amount of collagen is laid down in the treated zone as it heals, but that is not a tightening effect. A pocket that shrinks under skin that has lost its recoil can look looser afterwards, which is why skin quality is examined before it is discussed and why laxity-dominant necks are steered towards radiofrequency or focused ultrasound instead.
References
KYBELLA (deoxycholic acid) injection: prescribing information. US Food and Drug Administration, 2015. source
Deoxycholic acid: a review in submental fat contouring. American Journal of Clinical Dermatology, 2016. source
Chronic infection and nodule formation following deoxycholate injection. Archives of Plastic Surgery, 2022. source
About this page: written and medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last reviewed 20 October 2026 · Illustrative images only, not patients · Editorial policy
