The US Food and Drug Administration has approved revised labeling for deoxycholic acid (Kybella, Allergan Aesthetics) that names injection-site nodules, masses exceeding 3 cm, and neuromuscular adverse events as serious risks when the drug is delivered outside the submental fat region — its only approved anatomic site.

The labeling change follows the agency's review of the FDA Adverse Event Reporting System (FAERS, now the FDA Adverse Event Monitoring System) and the published medical literature. The FDA recommends against using deoxycholic acid for any indication beyond submental fat.

What does the new labeling specify?

The FDA cleared additional language in the Warnings and Precautions section describing two categories of injection-site lesions:

• Nodules measuring 3 cm or smaller
• Masses larger than 3 cm

Both can develop after on-label submental injections and after off-label injections placed outside the submental fat region. The agency states these lesions may not resolve over time and may require medical intervention.

What triggered the review?

Deoxycholic acid disrupts the membrane of fat cells and reduces submental fullness through that cytolytic mechanism. When the agent is delivered outside the fat compartment intended, the same action can injure adjacent tissue. The FAERS review surfaced reports of:

• Neuromuscular adverse events following off-label injection
• Persistent subcutaneous nodules at the treatment site
• Larger inflammatory masses that, in some cases, required drainage or surgical management

The FDA tied the revision to an "association" between deoxycholic acid and the two lesion categories, without releasing a count of the underlying FAERS reports. It also noted that nodules and masses may occur whether patients receive the drug as indicated in the submental fat region or outside that region.

How should practices adjust?

For clinicians, the practical changes are concrete:

• Consent forms must reflect the updated Warnings and Precautions text
• Treatment notes should record the anatomic target of every injection
• Practices that have marketed deoxycholic acid for off-label body-contouring must update protocols and patient-facing materials
• New nodules, masses, or neuromuscular symptoms should be reported through MedWatch, the FDA's safety reporting system

Allergan Aesthetics markets Kybella for submental fat. The new warning applies to that indicated use and to any off-label administration; it does not narrow the FDA-approved indication.

What stays the same — and what may change?

The labeling update does not alter the drug's approved use or require new coding. Coverage decisions for submental deoxycholic acid injections from commercial payers and Medicare remain tied to the existing indication. Patients already scheduled for indicated treatment can proceed under the revised consent language.

The agency did not add a boxed warning, restrict distribution, or mandate a Risk Evaluation and Mitigation Strategy in this action. That leaves the door open for further regulatory measures if post-marketing reports continue to identify serious events at off-label sites, particularly as non-surgical fat-reduction procedures compete with submental deoxycholic acid in clinical practice.