Deoxycholic acid (Kybella)

Also known as: Kybella, ATX-101, Belkyra

Deoxycholic acid is a synthetic copy of a bile acid that dissolves fat cell membranes. Injected in a grid pattern under the chin, it permanently destroys submental fat over a series of sessions. It is FDA approved for that one use and the approval rests on four phase 3 randomized placebo-controlled trials, so the double-chin evidence is genuinely strong. The trade-offs are real: substantial swelling for days to weeks after each session, multiple sessions needed, and a small risk of temporary nerve injury causing an uneven smile. Every other body area is off-label with little published data.

How it works

Deoxycholic acid is a detergent-like molecule. Injected directly into subcutaneous fat, it disrupts fat cell membranes and destroys the cells, which the body then clears through inflammation over several weeks. Destroyed fat cells do not come back, so results are considered permanent at a stable body weight.

What the evidence says, claim by claim

These are the results measured in studies, not the results shown in ads. Where the research is weak, the grade says so.

For double chin

Strong evidence

Four phase 3 randomized placebo-controlled trials support the FDA approval. In REFINE-1, significantly more ATX-101 patients than placebo patients improved at least 1 grade on both clinician and patient submental fat scales 12 weeks after the last treatment, with MRI-confirmed fat reduction. A European phase 3 trial published in 2014 showed the same pattern. In the long-term CONTOUR follow-up, most responders maintained improvement, consistent with permanent fat cell destruction.

Multiple randomized controlled trials or a meta-analysis support this use. The effect is real and repeatable.

ATX-101 for reduction of submental fat: A phase III randomized controlled trial (Journal of the American Academy of Dermatology, 2016; RCT)
Reduction of unwanted submental fat with ATX-101 (deoxycholic acid), an adipocytolytic injectable treatment: results from a phase III, randomized, placebo-controlled study (British Journal of Dermatology, 2014; RCT)
ATX-101 (Deoxycholic Acid Injection) Leads to Clinically Meaningful Improvement in Submental Fat: Final Data From CONTOUR (Dermatologic Surgery, 2020; cohort)

For skin laxity

Not enough evidence

Some clinics market deoxycholic acid as tightening skin while it dissolves fat, and it is also used off-label on jowls and small body fat pockets. Trials assessed skin laxity mainly as a safety endpoint (checking it did not worsen after fat removal), not as an improvement outcome, and a 2024 systematic review of off-label submental and jowl use focused on managing complications rather than proving benefit. There is no controlled evidence that it tightens skin.

The marketing has moved faster than the research. There is no good human data behind this use yet.

ATX-101 for reduction of submental fat: A phase III randomized controlled trial (Journal of the American Academy of Dermatology, 2016; RCT)
Management of Serious Adverse Events Following Deoxycholic Acid Injection for Submental and Jowl Fat Reduction: A Systematic Review and Management Recommendations (Aesthetic Surgery Journal Open Forum, 2024; systematic-review)

Risks and what can go wrong

Expect real downtime: swelling, numbness, bruising, and firmness under the chin lasting days to a few weeks after each session, often most dramatic after the first. Temporary marginal mandibular nerve injury, which causes an asymmetric smile, occurred in up to about 4 percent of trial patients and resolved over weeks to months; dysphagia (trouble swallowing) occurred in about 2 percent. Rare reports include skin ulceration from too-shallow injection and patchy hair loss at the injection site. Precise injection depth and staying within the marked safe zone are skill-dependent, so injector experience matters. Not for people with infection at the site; those with prior neck surgery or swallowing problems need careful evaluation.

The practical details

Typical US pricing is 1,200 to 1,800 dollars per session, and most people need 2 to 4 sessions spaced at least a month apart, so full treatment commonly totals 2,400 to 6,000 dollars. Fat reduction is permanent at stable weight, so no maintenance is needed once the goal is reached. FDA approved (2015) only for moderate to severe submental fat in adults; jowls and body areas are off-label. Many practices now steer heavier submental fat cases to liposuction, which handles large volumes in one session.