A double chin, medically known as submental fullness, is one of the most common concerns patients raise about their profile — and one of the most frequently misunderstood, since it isn't always related to overall weight.
Why a Double Chin Isn't Always About Weight
Submental fullness can be caused by excess fat beneath the chin, loose or lax skin, a naturally recessed chin position, or some combination of the three. According to the American Academy of Dermatology (AAD), genetics and aging both play a significant role in submental fat, which is why even people at a healthy weight can have a persistent double chin, and why weight loss alone doesn't always resolve it.
The Role of Chin Position and Bone Structure
One often-overlooked factor is underlying bone structure. A recessed or naturally smaller chin can make even a modest amount of submental fat look more prominent, simply because there's less forward projection to balance it visually. This is why two people with a similar amount of fat under the chin can look quite different — and why an accurate assessment of the full profile, not just the fat itself, matters when deciding on a treatment plan. In some cases, addressing chin projection (through filler or other means) alongside fat reduction produces a more balanced result than treating the fat in isolation.
Treatment Depends on the Cause
Because submental fullness has more than one possible cause, the right treatment depends on which one is driving it:
Excess Fat
Kybella (deoxycholic acid) is an FDA-approved injectable specifically designed to destroy fat cells beneath the chin. It's injected directly into the treatment area over a series of sessions, and because it destroys the fat cells rather than just shrinking them, results are considered permanent once the treatment plan is complete.
Skin Laxity
When the primary issue is loose or lax skin rather than fat volume, a skin-tightening treatment like XERF may be more appropriate, since it works by stimulating collagen rather than reducing fat.
Both
Many patients have a combination of fat and laxity, in which case a provider may recommend Kybella first to reduce volume, followed by a tightening treatment to address any remaining skin laxity once the fat has resolved.
Kybella vs. Surgical Neck Lift: How to Decide
For patients with a larger volume of submental fat or significant skin laxity, a surgical neck lift performed by a plastic surgeon may achieve more dramatic results in a single procedure. However, it involves anesthesia, incisions, and a longer recovery period measured in weeks rather than days. Kybella, by contrast, involves no surgery and minimal downtime, but requires multiple sessions spaced roughly a month apart and produces more gradual results. For patients with mild to moderate submental fullness who want to avoid surgery, Kybella is typically the first option discussed; more significant cases may be better served by a surgical consultation.
What to Expect With Kybella
Kybella requires a series of treatment sessions, typically spaced about a month apart, with visible improvement building gradually as the body clears the treated fat cells. Most treatment plans involve two to four sessions total, though this varies by the amount of fat present and individual response. Temporary swelling, bruising, numbness, and firmness in the treated area are common in the days following each session and are considered a normal part of how the treatment works.
How Long Do Results Last?
Because Kybella permanently destroys the treated fat cells, results are considered long-lasting once the full treatment series is complete. As with any fat-reduction treatment, however, significant future weight gain can cause new fat accumulation in the area, so maintaining a stable weight helps preserve results over time.
Frequently Asked Questions
How many Kybella sessions will I need?
Most patients need between two and four sessions spaced about a month apart, though this depends on the amount of fat and desired outcome.
Is Kybella painful?
Discomfort is generally mild to moderate; the treatment area is typically numbed beforehand, and any soreness afterward is usually managed with over-the-counter pain relief.
Can Kybella help if my double chin is from loose skin, not fat?
Kybella targets fat specifically; if skin laxity is the primary cause, a skin-tightening treatment like XERF is typically more effective.
How long is recovery after Kybella?
Most patients experience swelling for several days to about two weeks and can typically resume normal activities immediately, working around visible swelling as needed.
At what age does a double chin typically develop?
It can occur at any age depending on genetics and fat distribution, though skin laxity contributing to it tends to become more common with age.
Getting the Right Diagnosis
Because fat and skin laxity require different treatments, the most useful first step is a consultation where a provider can determine which is driving your specific concern, and build a plan around it.
Learn more about Kybella at Journelle Skin, or schedule a consultation to find the right approach for your profile.