Fat Dissolving Injections in Singapore:
What Deoxycholic Acid Does, and What It Does Not

What do fat dissolving injections actually do to a fat cell?

Deoxycholic acid is a detergent-like bile acid. The body makes it in the liver to emulsify dietary fat in the gut. The injectable form is a synthetic copy of the same molecule, prepared at a fixed concentration and injected in small amounts across a grid under the chin.

Once it is in the fat layer it inserts itself into the membrane of the fat cell (the adipocyte) and breaks that membrane open. The cell cannot survive this, and the body treats the debris as it would any injury: inflammatory cells move in, the fatty contents are taken up and carried away, and the pocket becomes thinner as that clearance proceeds. The swelling, warmth and tenderness that follow an injection are not a side effect in the usual sense; they are the clearing process itself, and they are expected.

Two properties follow and both matter for planning. First, deoxycholic acid is not selective for fat: where it meets skin, muscle, nerve or a salivary gland it does the same thing, which is why it is injected at a defined depth, kept away from the jawline and the marginal mandibular nerve, and never placed into the platysma or the submandibular gland. Second, it acts on fat cells rather than on the skin above them, so a pocket that shrinks under skin that has lost its recoil can look emptier rather than tighter.

Where the molecule came from

The injectable form was developed as ATX-101 and tested against placebo in two phase 3 trials, REFINE-1 and REFINE-2, before the US Food and Drug Administration approved it in 2015 as Kybella (Belkyra in some other markets). Those trials and the pooled safety data in the prescribing information remain the evidence base.

Where are fat dissolving injections used, and where are they not?

The approved indication is a single site: moderate to severe convexity or fullness associated with submental fat in adults, the area between the chin and the neck. That is where the registration trials were run and where the injection grid, the depth and the no-go zones have been worked out.

Use on the jowl, the bra-line, the inner knee, the upper arm or the abdomen is off-label. On the body the pockets are larger, so the volume of medicine needed rises quickly and the swelling with it, which is one reason energy-based methods are usually considered first for body pockets.

Where it is a reasonable question

• A soft, pinchable pad under the chin that persists at a stable weight, in a person whose skin still recoils when pinched.
• A small, discrete fat pad along the jawline, after examination has confirmed it is fat and not descended tissue (see jowl fat versus sagging).
• A small residual pocket after other treatment, where the shape rather than the volume is the problem.

Where it is the wrong question

• Fullness that is mostly loose skin or a lax platysma. Removing fat from under slack skin can make the neck look older, not younger.
• A short or recessed chin, which makes a modest amount of submental fat look larger. The answer there is projection, which is the territory of chin enhancement.
• A prominent submandibular gland, which sits below the jaw on each side and is not fat at all.
• Weight. Deoxycholic acid changes the shape of one small pocket and does nothing for body weight or visceral fat.

The double chin treatment page sets out how those four causes are separated at assessment, because the same profile can be any of them.

“I do not inject anything under a chin until I know whether the fullness is fat, skin, platysma or a short chin. Deoxycholic acid answers one of those four, and it is not the commonest one.”

Dr Sin YongOn Fat Dissolving Injections in Singapore

How do fat dissolving injections differ from fat freezing, Onda Pro and the 4K Body Lift?

All four act on subcutaneous fat, and none of them is weight loss. They differ in how the fat cell is damaged, in what happens to the skin above it, and in the size of pocket each is suited to.

Two practical differences follow. A medicine spreads where it is injected and is dosed by the number of injection points, so it suits a pocket small enough to map with a grid. Energy devices treat the volume under an applicator or a needle array, so they suit larger or flatter pockets and can address the skin at the same time. The fat dissolving versus fat freezing comparison goes through the first two in more detail.

Are fat dissolving injections available in Singapore?

Three regulatory layers apply, and they are often confused in advertising.

The product. Deoxycholic acid injection is a prescription medicine. In Singapore a therapeutic product must be registered with the Health Sciences Authority (HSA) before it can be supplied, and an injectable product cannot be sold as a cosmetic however it is described on the label. Whether a registered deoxycholic acid product is stocked at any given time varies, and it is confirmed at consultation rather than assumed from a web page.

The procedure. The Singapore Medical Council's Guidelines on Aesthetic Practices for Doctors (2016 edition) list the procedures a doctor may offer and the training expected for each. Mesotherapy, the older practice of injecting mixed or compounded lipolytic cocktails, is no longer permitted outside an approved clinical trial. A registered single-agent prescription medicine used for its labelled indication by a registered doctor is a different situation from a compounded cocktail, and a doctor is expected to be able to explain which of the two is being proposed.

The injector. Prescription medicines are prescribed and administered by a registered medical practitioner. Products sold online or injected in salons, including those marketed as fat dissolving, fall outside both the product and the practitioner rules, and HSA has repeatedly warned about unregistered injectables bought online.

The regulation of aesthetic medicine in Singapore page explains how the SMC, HSA and clinic licensing rules fit together.

Who should not have fat dissolving injections?

The commonest reason to decline is that the fullness is not fat. Beyond that, the prescribing information and ordinary clinical judgement set out several groups for whom deoxycholic acid is unsuitable or needs a different plan.

• Laxity-dominant necks. Where the skin folds rather than bulges, or gathers when the head tilts down with little fat on pinch, removing fat makes the laxity more visible. Focused ultrasound or radiofrequency is the relevant conversation; see HIFU for a double chin.
• Large volumes. A heavy submental pad, or body pockets, need more medicine and produce more swelling than most people will accept, and may be better served by energy devices or by referral to a plastic surgery specialist for liposuction.
• Anyone with difficulty swallowing, now or in the past, because the medicine can worsen it.
• Infection or active skin disease at the injection site, and a history of surgery or scarring under the chin that has changed the anatomy.
• Bleeding disorders or blood-thinning medicines, which raise the chance of bruising and haematoma.
• Pregnancy and breastfeeding, where there is no safety data.
• A short chin or prominent gland, because the fat is not what is producing the profile.

Age by itself is not a bar, but skin quality is. A pinch test, a tilt test and, where earlier filler is involved, ultrasound mapping to distinguish fat from filler are part of the examination before any option is chosen.

Side effects and aftercare

The expected reaction is swelling, warmth, tenderness, redness, bruising and firmness across the injected area, and some numbness. The pooled trial data in the prescribing information list injection-site swelling as the commonest reaction, followed by haematoma, pain, numbness, redness and induration. Swelling is more marked than after most injectables because it is the clearing process at work, and the area can look fuller before it looks smaller.

Less common effects are the ones that decide the no-go zones. Injury to the marginal mandibular nerve, which runs along the jawline, can cause a temporary asymmetric smile or weakness of the lower lip. Difficulty swallowing has been reported. Skin ulceration and tissue injury can follow an injection placed too superficially. Hair loss at the injection site has been reported after approval. None of these is common, and all of them are reduced by mapping the grid away from the jawline, injecting at the correct depth and keeping to the approved area.

Aftercare in broad terms

• Expect the area to swell and feel firm; cool compresses help, and the swelling settles gradually rather than overnight.
• Avoid pressing, massaging or lying face-down on the area while it is swollen.
• Keep the skin clean and avoid make-up on the injection points until they have closed.
• Report any weakness of the smile, trouble swallowing, skin colour change or spreading redness promptly.
• The response is reviewed before any further treatment is considered; the interval between reviews is set at consultation.

How a double chin or small fat pocket is approached here

Dr Sin Yong, an aesthetic physician on Orchard Road, Singapore, examines the area in person before any method is named. For a double chin that means separating fat, skin laxity, platysma position and chin projection, because they look alike from outside and respond to different things. For a body pocket it means a pinch test and posture test to confirm the pocket is subcutaneous fat rather than visceral fat, loose skin or muscle separation.

Where the problem is fat and the pocket is pinchable, the energy-based options on this site are fat freezing, Onda Pro and the 4K Body Lift. Where skin has lost recoil, the VF Lift – Vertical Figure Lift on Volnewmer treats the dermis along vertical vectors and is not a fat treatment. Where the chin is short, chin enhancement changes the angle itself. Where fat dissolving injections are discussed, they are discussed as a prescription medicine with an approved area, a known side-effect pattern and a dependence on product availability, not as a default answer.

Fees for any plan are set in writing after assessment; how fees are quoted explains what decides them.