Treating a double chin with Botox typically requires 20 to 40 units, depending on whether the goal is tightening the jawline, smoothing vertical neck bands, or both. But there’s an important distinction worth understanding first: Botox doesn’t dissolve fat. If your double chin is caused by excess fat under the skin, Botox alone won’t fix it. What Botox does is relax the muscles that pull the lower face and neck downward, creating a tighter, more defined look along the jawline and neck.
What Botox Actually Does for a Double Chin
The appearance of a double chin can come from two different sources: submental fat (the pocket of fat beneath your chin) or muscle laxity in the neck and jaw area. Botox only addresses the muscle side of that equation. The platysma, a thin sheet of muscle that runs from your chest up through your neck and jaw, can pull the lower face downward as it loosens with age. When this muscle is overactive or lax, it creates visible vertical bands in the neck and contributes to sagging along the jawline, both of which make a double chin look more pronounced.
By relaxing the platysma, Botox reduces that downward pull. The result is a sharper jawline, smoother neck, and less fullness in the area beneath the chin. This works best for people with mild sagging, early jowling, or visible neck banding rather than significant fat deposits.
Units for Platysmal Bands
Vertical neck bands, the rope-like lines that become visible when you clench your neck, are one of the most common targets for Botox in this area. The standard protocol uses about 40 units total, spread across 20 injection points on both sides of the neck. Each point receives 2 units, with five points spaced roughly 2 centimeters apart along each band. Injections go directly into the muscle after the provider locates the bands by touch.
Smoothing these bands removes one of the visual cues that makes the chin-to-neck transition look heavy or undefined. For many people, this alone creates a noticeable improvement in how the neck and chin area looks in profile.
Units for Jawline Contouring (Nefertiti Lift)
The Nefertiti Lift is a specific Botox technique that targets the platysma along the jawline itself. The goal is to weaken the muscle’s downward pull so the muscles that lift the face can work unopposed, producing a subtle lifting effect along the jaw.
This technique uses about 20 units per side, for a total of 40 units. Injections are placed in two rows: one just above the jawbone and one slightly below it. Each row has five injection points, spaced 2 centimeters apart, with 2 units at each point. These injections are placed at a very shallow depth, just beneath the skin rather than deep into muscle, to avoid affecting nearby muscles that control the lower lip.
When combined with platysmal band treatment, the total can reach 60 to 80 units across the full neck and jawline area. Your provider will decide which zones need treatment based on your anatomy and goals.
When Botox Isn’t the Right Choice
If the main issue is a visible pocket of fat beneath your chin, Botox won’t produce the results you’re looking for. That fullness comes from stored fat cells, not muscle activity, and Botox has no effect on fat. Kybella, a different injectable, is designed specifically for this problem. It contains a substance that permanently destroys fat cells in the submental area, physically reducing the volume under the chin over a series of treatments.
The simplest way to tell the difference: if your double chin looks the same whether your neck muscles are relaxed or tensed, the issue is likely fat. If the area looks worse when you look down or clench your jaw, and you can see vertical bands or sagging skin, muscle activity is playing a role and Botox can help. Many people have some combination of both, which is why providers sometimes recommend Botox alongside Kybella or other treatments.
Botox can also be injected into the masseter muscles at the back of the jaw to slim a square jawline, but that’s a separate treatment from chin and neck contouring. Masseter Botox typically uses 20 to 30 units per side and addresses facial width rather than submental fullness.
Results Timeline and Duration
Most people notice changes within a few days of treatment, with full results visible at around two weeks. The jawline looks more defined, neck bands soften, and the overall chin-to-neck profile appears tighter. Results typically last 3 to 4 months before gradually fading as the muscle regains its normal activity. Repeat treatments are needed to maintain the effect, though some people find that with consistent treatment over time, they can go longer between sessions as the muscle weakens from repeated relaxation.
Risks Specific to Neck Injections
The most notable risk of Botox in the neck area is temporary difficulty swallowing, known as dysphagia. This happens when the toxin spreads beyond the target muscle into nearby throat muscles. In clinical studies, the reported rate varies widely, from about 1% to 27% depending on the dose and injection site. Higher doses injected into larger neck muscles carry a greater risk. The cosmetic doses used for platysmal bands and jawline contouring (40 to 80 units total) are considerably lower than the therapeutic doses used for conditions like cervical dystonia, which can exceed 100 to 150 units in a single muscle. Still, mild swallowing difficulty or a sensation of throat tightness is possible and typically resolves within a few weeks.
Other common side effects include temporary bruising, mild pain at injection sites, and neck weakness or stiffness. Choosing a provider experienced in neck anatomy reduces these risks significantly, since precise placement and depth control are critical in this area.
Cost Expectations
Botox is priced per unit, typically ranging from $10 to $20 per unit depending on your location and provider. For a platysmal band treatment at 40 units, you’d expect to pay roughly $400 to $800. A full Nefertiti Lift at 40 units falls in the same range. If both areas are treated in the same session at 60 to 80 total units, the cost runs approximately $600 to $1,600. These treatments are cosmetic and not covered by insurance.