Double chin injections: what's different about the ingredients? Choosing between Kybella Plus and liposuction

Among injections to reduce double chins, the deoxycholic acid injection—the same as in Kybella Plus—was the first non-surgical method confirmed in a large clinical trial.[1]Injections using a different ingredient, phosphatidylcholine, were noted in expert statements to lack complete efficacy and safety data.[2]For people with a large amount of fat, or those whose fullness is caused by something other than fat, alternative methods such as liposuction may be more suitable.[3].

What's different about fat-dissolving injections with different ingredients?

The main difference is how thoroughly efficacy and safety have been established. Fat-dissolving injections using phosphatidylcholine originally spread as off-label use.[2].

In a 2009 expert panel statement, efficacy and safety data for this injection had not yet been established, and it was recommended that further research be conducted before cosmetic use.[2]Subsequent research has shown that in these earlier injections, deoxycholic acid is the primary agent responsible for fat destruction.[1].

Kybella Plus is a deoxycholic acid injection. However, there have not yet been large clinical trials examining the Kybella Plus product itself. Here, we explain based on trials of the approved drug with the same ingredient (ATX-101).

How much change does a deoxycholic acid injection produce?

More than half of patients showed visible improvement. In a combined analysis of two European trials, patients received up to 4 injections at approximately 28-day intervals, and 63.8% showed improvement on physician assessment, exceeding the 28.6% rate for placebo (injections without active ingredient).[1].

65.4% of patients were satisfied with their appearance, higher than the 29.0% for placebo.[1]Some people worry that reduced fat might cause skin sagging (skin laxity), but skin sagging generally did not worsen.[1].

The effect was maintained for up to 3 years in most patients.[4]However, it has been noted that all trials received corporate support.[4].

How does it differ compared to liposuction?

Liposuction remains the standard method for substantial fat reduction.[3]Surgical approaches produce larger changes, but may not suit those who want to avoid costs and lengthy recovery periods.[5].

Injection is a method with minimal downtime, less pain, and lower bodily stress.[3]In exchange, patient selection is important, injector skill matters, and multiple visits are required.[3]Treatments that cool tissue to reduce fat are also used as options for submental fat.[5].

How long do swelling and numbness last?

Expect swelling and numbness in nearly all patients. In a report of 167 patients, swelling occurred in 99.4% lasting an average of 6.9 days, and numbness occurred in 97.6% lasting an average of 29.2 days.[6].

Most reactions settled within the 28-day interval before the next injection, and duration shortened after the second treatment onward.[1]Strategies exist to reduce swelling and pain; in a small 14-patient trial mixing small amounts of steroid and anesthetic, pain and swelling were reduced while maintaining efficacy.[5].

Serious side effects are rare.[7]However, injecting large volumes at once has been reported to increase the risk of serious side effects.[7].

How often does nerve paralysis around the mouth occur?

Rarely, the nerve controlling the mouth corners becomes temporarily paralyzed, making the smile appear asymmetrical.[1][6]This frequency was reported as 4.3% in trials, comparable to the 1–5% rate for liposuction or neck lift surgery.[6].

Paralysis lasted an average of 27.0 days and resolved without sequelae in all trial cases.[1][6]To avoid the nerve, it is recommended not to inject below 1.0–1.5 cm from the edge of the jaw bone.[6].

What should the consultation verify to find the right method for you?

What needs to be confirmed is whether fullness is caused by fat or tissue descent. For jawline fullness, if caused by tissue descent, surgery is more suitable; if the skin below is thin, fat-reduction injection is not recommended.[8].

Special care is needed for those who have previously received fat-dissolving injections, those taking blood-thinning medications, and pregnant individuals.[8]During consultation, ask about the product ingredients, expected number of treatments, and areas not to be injected, then have the under-chin area examined in person to make a decision.