If you’re researching Kybella for a double chin, questions about side effects are a reasonable place to start. Kybella (deoxycholic acid) destroys fat cells, and that process comes with a predictable inflammatory response. Most side effects are temporary and manageable. The rare serious risks are real, and you deserve a clear account of both.
I’ve been performing Kybella injections at Synergy Face + Body by Travis Shaw in Richmond and Midlothian for several years. Over that time I’ve refined my injection technique specifically to reduce the most common side effects. What follows is what I actually observe in my patients, alongside what the FDA studies show.
Common Kybella Side Effects
The majority of side effects after Kybella are local reactions at the injection site. They’re expected as part of the fat-destruction process and resolve on their own.
Swelling
Swelling is the most predictable side effect and the one patients talk about most. It typically peaks within the first one to two days and resolves within three to seven days for most patients, though some residual swelling can linger for up to two weeks after each session.
One technique change I made early in my experience has made a meaningful difference. When I was originally trained on Kybella, the protocol called for pre-injecting the area with lidocaine to reduce discomfort. What I found in practice was that this essentially doubled the volume of fluid going into the submental space — and more fluid in meant more swelling out. I now use ice before, during, and after injections instead. Patients who have experienced both approaches consistently prefer icing, and they describe it as more comfortable than lidocaine (which stings when injected). Post-treatment swelling has been noticeably less with this approach. I also have patients wear a light compression dressing for the first few evenings to reduce fluid accumulation.
The practical question patients usually ask: will you be able to go to work or an event? Plan for three to five days of visible swelling. The treated area will look and feel fuller before it looks better.
Bruising
Bruising is possible but less common than swelling, and it’s largely preventable. Aspirin, NSAIDs like ibuprofen or naproxen, and many supplements thin the blood enough to increase bruising risk. I ask patients to stop these at least 10 days before treatment.
For patients who bruise easily, eating fresh pineapple in the days around treatment can help. Pineapple contains bromelain, an enzyme with natural anti-inflammatory properties. It’s a low-risk addition worth trying if bruising runs in your history.
Numbness
Temporary numbness or tingling in the chin and submental area is common after Kybella. It’s caused by the effect of deoxycholic acid on local tissue and typically resolves within a few weeks, though in some patients it can persist a few months. For most patients it’s more of a curiosity than a real complaint — they notice it when touching the area but it doesn’t interfere with daily life.
Nodules and Firmness
Small hardened areas under the chin are common in the weeks following treatment and sometimes catch patients off guard when they feel them. These are part of the normal healing response as the body processes and clears destroyed fat cells. They’re temporary and resolve as healing progresses, usually within a few weeks to a couple of months.
Rare but Serious Kybella Risks
Most patients won’t experience these, but you should know they exist and what to watch for.
Marginal Mandibular Nerve Injury
The most clinically significant risk is injury to the marginal mandibular branch of the facial nerve. This nerve runs near the lower jawline and controls muscles involved in pulling the corner of the mouth downward. If it’s affected, the result is an asymmetrical smile or temporary weakness in the lower face. This complication is directly tied to injection depth and placement accuracy. Published case studies confirm the risk is real but uncommon, and the majority of reported cases have resolved over time. It’s one of the clearest reasons why injector experience and anatomical precision matter.
Difficulty Swallowing
Swelling in the treatment area can occasionally cause temporary dysphagia, meaning difficulty or discomfort when swallowing. It’s typically mild and resolves as swelling subsides. Contact your provider if swallowing difficulties are significant or worsening.
Tissue Damage
In rare cases, particularly with incorrect injection depth, Kybella can cause necrosis (tissue cell death) or skin ulceration. This is a serious complication and reinforces why the technical skill of the person injecting you is not a minor consideration.
Hair Loss
A small number of patients report temporary hair loss in the treatment area. This is uncommon and typically resolves on its own.
Does Kybella Affect the Thyroid?
This question comes up often enough to address directly. Patients sometimes wonder whether injections near the upper neck could affect thyroid function. Kybella is injected into the subcutaneous fat of the submental area — the layer of fat just beneath the skin under the chin. The thyroid gland sits much deeper in the anterior neck, separated by muscle and other anatomical structures. There is no established mechanism by which correctly administered deoxycholic acid would reach or affect thyroid tissue, and no credible clinical evidence linking properly performed Kybella to thyroid problems.
If you have a thyroid condition, disclose it in your health history. It’s relevant to your overall health picture and may be part of why submental fat accumulated in the first place — hypothyroidism can contribute to fat deposition in the neck area. But it doesn’t make a thyroid reaction to Kybella more likely.
Long-Term Side Effects of Kybella
Most of Kybella’s side effects are short-lived. Swelling resolves within weeks. Numbness typically resolves within months. Nodules resolve as healing progresses. Nerve injuries, when they occur, have resolved in the majority of reported cases.
One thing worth naming that isn’t a side effect but matters for long-term expectations: Kybella permanently destroys fat cells in the treated area. Results are long-lasting for this reason. However, significant weight gain after treatment can cause fat to accumulate in adjacent, untreated areas. Understanding this is part of making an informed decision about the procedure.
How Much Does Kybella Hurt?
Pain is manageable for most patients. With ice used for comfort rather than lidocaine injections, patients feel brief individual needle sticks followed by a mild burning sensation as the deoxycholic acid is deposited. The sensation subsides quickly. Most patients describe the overall experience as very tolerable, and the treatment itself takes 15 to 20 minutes.
When to Contact Your Provider
Call your provider if you experience any of the following after treatment:
- An asymmetrical smile or weakness in the muscles around your mouth or jaw
- Difficulty swallowing that is significant or getting worse
- Signs of infection at the injection site: increasing redness, warmth, pain, or discharge
- Skin changes that look like blistering or open sores
If you have questions about whether Kybella is the right approach for your goals, we’re happy to talk through your options at a consultation. Reach us online or call Synergy Face + Body by Travis Shaw at 804-406-3364. We see patients at our Richmond and Midlothian, Virginia locations.
