This month, we review “Sodium Deoxycholate for Submental Folding.” This study may be of interest to the public in the context of treatments for double chins. Kybella is a relatively new FDA approved drug for the cosmetic treatment of minor double chins, called submental folding. The original article1 can be found at Skin Therapy Letter.
Context: Why You Might Care
Excess fat around the jaw (called submental folds) is a common concern among middle-aged or older people and is often regarded as one of the markers of aging. Naturally, this will vary from individual to individual, but the chin is a common area where fat accumulates. Most people do not like the appearance of double-chins or folds under their chin.
- Fat around the chin area is often unpleasant and is frequently difficult to remove through diet and exercise alone.
- There is little sound evidence that face exercises and the like have any measurable effect on double chins.
- Weight loss will help reduce fat in the chin area (along with everywhere else), but double-chins can’t be removed with “targeted fat loss.”2
- Surgical interventions like chin liposuction or a facelift are very effective and considered the main therapy for double-chin. These procedures are surgeries, and as is true of any invasive procedure, they come with risks and high costs.
- Sodium deoxycholate (trade name Belkyra in Canada or Kybella in the US) offers an alternative treatment option that does not require surgery for patients that do not wish to undergo surgery.
Deoxycholic Acid
Sodium deoxycholate is a bile salt that occurs in the body, and researchers have found that it can selectively dissolve fat tissue while not having the same effect on other tissue like skin or muscle. The idea is that using the properties of deoxycholic acid may provide an alternative solution to submental folds (double chin) without surgery if it can safely remove fat in a targeted manner. Researchers synthesized the acid for the purpose of contouring the chin and neck area. The clinical trial in question studies the synthetic compound ATX-101, a consistent sodium deoxycholate formulation.
Results and Mechanism of Action
Mechanism of action is the technical name in pharmacology for how a drug interacts and produces its intended effect. Adipocytolysis is the proposed mechanism of action. The adipose (fat) tissues go through cell death over time following treatment. The strategy is similar to that of certain laser treatments, where the goal is to stress specific fat cells to induce programmed cell death (apoptosis).3 The end goal is for the deoxycholic acid to trigger a state where the fat cells get absorbed by the body’s immune system, and the clinical trial results show evidence of efficacy.
- The clinical trials that are looked at are double-blinded and placebo-controlled and in phase III.
- MRI imaging was used in the studies to measure the decrease in submental volume.
- The psychological effect of a change in appearance was also measured.
- Both European and North American trials show clear evidence of efficacy beyond placebo.
- After two treatments over 50% of those treated, and more than 70% of the patient showed an increase in one baseline in all categories.
- Data suggests the long-lasting effects (at least four years after treatment).
- Readers can review the original article to view before and after images from the trials.
Safety Profile and Adverse Effects
Testing for safety and adverse effects is an integral part of any trial for drugs prior to approval for public use. Sodium deoxycholate returns to baseline levels 24 hours after injection.4 Pain, swelling, bruising, numbness, erythema (redness), and induration (thickening of the skin) were the most common side-effects. These side-effects were specific to the treated area and were an expected mechanism of action of the compound. With repeated treatment, the severity of pain and swelling declined. Skin laxity, due to a quick loss of fat volume, was not an issue in the clinical trials.5
Conclusion and Status
Deoxycholic acid has been approved by Health Canada and the FDA to treat double chin (submental folds) specifically. It is not yet approved for use in other areas of the face or the body.
- Unlike the vast majority of injectable fillers and neuromodulators (like Botox), the results are long-lasting.
- “Maintenance treatments” or follow-ups are unnecessary.
- Results will be visible in two to four treatments.
- Recovery time is minimal.
- Physicians should only treat patients with sufficient submental fat (fat on the chin area).
- Physicians must exercise caution to avoid injury to other areas during the injection.
Takeaway and Caveats
As always, this is not intended as a promotion or endorsement of a particular drug or treatment, but a summary of technology and treatments that may interest the reader. We encourage everyone to look at the source. Kybella® (US) and Belkyra™ (Canada) have been in the market, and cosmetic dermatologists have used these treatments successfully.
- Submental fullness (double chin, excessive fat in the area) is a very common concern that can be the result of aging, weight gain, or genetics, or a combination of these factors.
- Sodium deoxycholate (Kybella/Belkyra) offers patients a non-surgical option for treating excess fat under the chin.
- Clinical trial results show promise of effectiveness.
Dr. Shannon Humphrey, a dermatologist in Vancouver, British Columbia, was one of the investigators in the studies and currently uses this treatment to treat her patients. We’ve featured her in the past at DermLetter discussing how she treats double chin at her practice.
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1Humphrey S, Beleznay K, Carruthers J Sodium Deoxycholate for Submental Contouring. Skin Therapy Letter 2016 Dec 21-5 Sodium Deoxycholate for Submental Contouring There is a relevant conflict of interest disclosure reported in this study: Dr. Humphrey and Dr. Carruthers are investigators, speakers, and consultants for Kythera Biopharmaceuticals and Allergen Inc.
2Losing weight will certainly help. Unfortunately, you can’t choose specific spots to lose weight from; this myth persists inexplicably. Your genetics determine where fat is lost first and last.
3https://www.researchgate.net/publication/289868584_Help_of_dosimetry_in_interventional_adipocytolysis
4100mg of deoxycholic acid, 0.2ml injections, spaced at 1cm intervals.
4Sodium Deoxycholate for Submental Contouring
