| Injectable deoxycholic acid | Randomized, double-blind, placebo-controlled Phase III trial | 256 adults with moderate-to-severe submental fullness | 66.5% achieved at least a one-grade improvement on both clinician and patient-rated scales, compared with 22.2% with placebo | Swelling, bruising, pain, numbness, redness and firmness were common; several treatment sessions may be required | Strong randomized evidence for gradual reduction of submental fat in appropriately selected adults |
| Injectable deoxycholic acid | Second randomized, double-blind, placebo-controlled Phase III trial | 258 adults with unwanted submental fullness | 68.9% achieved the same combined clinician-and-patient improvement threshold, compared with 20.8% with placebo | Results depend on injection technique, treatment area, baseline fat volume and individual healing response | The Phase III findings were consistent across two controlled trials, but “improvement” does not mean complete removal |
| Combined Phase III evidence | Pooled analysis of two pivotal randomized trials | More than 1,000 randomized participants across the pivotal program | Consistent superiority over placebo for clinician-assessed and patient-reported reduction in submental fullness | Trial participants were selected adults; results may not apply to loose skin, prominent muscle bands or causes unrelated to fat | Best-supported nonsurgical option in this evidence set for fat-related fullness, subject to professional assessment |
| Weight management | General obesity and weight-loss evidence; no reliable localized double-chin endpoint | Varies by diet, exercise and clinical program | Overall weight reduction may decrease facial and neck fullness, but the amount is unpredictable | Cannot selectively target submental fat; loose skin may remain after weight loss | Appropriate as a general health strategy, but not a guaranteed standalone treatment for a double chin |
| Energy-based, noninvasive procedures | Smaller prospective studies and device-specific clinical trials | Usually smaller and more heterogeneous samples than pivotal injection trials | Some studies report reductions in fat thickness or circumference, but outcome definitions vary | Results are less directly comparable because devices, protocols and measurement methods differ | May be considered when a patient prefers a noninjectable approach, but evidence strength varies by technology |
| Submental liposuction | Surgical case series and observational evidence; not directly comparable with the Phase III trials | Varies by surgeon, technique and patient selection | Can provide a more immediate reduction when excess fat and skin elasticity are suitable | Surgery-related risks include bleeding, infection, contour irregularity, anesthesia complications and temporary numbness | Requires consultation with a qualified surgeon; outcomes depend strongly on skin quality and anatomy |