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Woman in blue shorts pinches fat in belly
Learn More About the Rare “Stick of Butter” Side Effect of CoolSculpting®

Technically known as cryolipolysis, Fort Worth CoolSculpting® is one of the fastest-growing non-surgical procedures to spot-reduce stubborn pockets of fat. It can be used on many parts of the body, though it is perhaps most commonly used on the abdominal wall. 

The skin and underlying fatty tissue are gently suctioned into a specialized applicator, which then lowers the temperature of the tissue between two cooling plates to -10ºC, freezing fat cells without harming surrounding skin, nerves, or blood vessels. The fat cells crystalize, disintegrate, and permanently leave the body as waste. 

Woman getting a CoolSculpting treatment at a medical spa

While this “fat-freezing” treatment delivers dependable results for the vast majority of patients, there is a rare potential complication called paradoxical adipose hyperplasia (PAH), which model Linda Evangelista has shed light on after developing the condition in 2015. You should be aware of PAH before undergoing the procedure, but thankfully, it is both rare and treatable.

What is paradoxical adipose hyperplasia (PAH)?

Paradoxical adipose hyperplasia is a rare complication of CoolSculpting that gets its name from the unexpected, paradoxical result: overgrowth (hyperplasia) of fatty (adipose) tissue. This complication, which can appear 8 to 24 weeks post-procedure, occurs when the treated area becomes hardened and visibly enlarged. The term “stick of butter side effects” refers to the shape the affected tissue takes, which reflects the shape of the CoolSculpting applicator.

According to a 2021 study, incidence rates of PAH were reduced by 75% with the newer CoolSculpting applicators, like those we use at our medical spa.

How does PAH look and feel?

A 2014 study published in JAMA Dermatology describes the appearance of PAH as “a sharply demarcated, rectangular enlargement around the umbilicus corresponding to the treatment zone.” The soft tissue protrusion is pliable, mobile, and slightly tender to the touch.

How common is the “stick of butter” side effect of CoolSculpting?

The “stick of butter” side effect is not common. Our practice has been offering CoolSculpting for many years, and we have not had any cases of PAH among many hundreds of patients. However, estimates range from 1 in 20,000 procedures to 1 in 256:

The odds of developing PAH are likely very low at a practice like ours with up-to-date technology and highly trained providers. The 2021 review also found that rates of PAH were reduced by over 75% with the use of newer CoolSculpting applicators and units. 

While the condition is unappealing and takes time to resolve, it is quite treatable with liposuction. There are also no known negative effects on the overall physical health of patients after PAH has resolved.

  • PAH is an overgrowth of fatty tissues
  • May occur in 1 in 4,000 to 20,000 cases
  • Treatable with liposuction
  • Kalos Medical Spa has never had a case of PAH
  • CoolSculpting: A cosmetic procedure that uses intense cold to reduce fat deposits in certain body areas. CoolSculpting® is FDA-cleared to treat visible fat bulges in 9 areas of the body. Some common side effects include temporary numbness, discomfort, and swelling.
  • Cryolipolysis: A non-invasive fat reduction technique that freezes and destroys fat cells.
  • Liposuction: A surgical procedure to remove fat from specific areas of the body.
  • Fat Cells: Cells in the body that store fat. During CoolSculpting, treated fat cells are targeted and destroyed by the intense cold temperatures that break down fat.
  • Side Effects: Unintended effects or reactions that may occur as a result of a medical procedure or treatment. Serious side effects are rare after CoolSculpting.
  • Subcutaneous Fat: Fat located under the skin, often resistant to diet and exercise. This is the “stubborn fat” or “unwanted fat” targeted with CoolSculpting.
  • Breast Implants: Medical devices inserted under the breast tissue and/or chest muscles to increase breast size.
  • Treatment Site: The specific area of the body where a medical or cosmetic procedure is performed.
  • Recovery Time: The period required for a patient to heal following a medical procedure.
  • Paradoxical Adipose Hyperplasia: A rare condition where treated areas increase in fat volume following cryolipolysis.
  • Fat Freezing: Another term for cryolipolysis, where cold temperatures are used to break down fat cells.
  • CoolSculpting Alternatives: Other procedures or treatments available for fat reduction besides CoolSculpting.
  • DualSculpting: Using two CoolSculpting machines simultaneously to treat multiple areas at once.
  • CoolTone: A procedure that uses magnetic muscle stimulation to strengthen and tone muscles.
  • Nonsurgical Fat Reduction: Techniques to reduce fat without surgery, such as cryolipolysis or laser treatments.
  • Consultation: A meeting with a healthcare provider to discuss treatment options and goals.
  • American Society of Plastic Surgeons: A leading organization representing board-certified plastic surgeons.
  • Board-Certified Plastic Surgeons: Surgeons certified by the American Board of Plastic Surgery, one of the 24 medical specialty boards recognized by the American Board of Medical Specialties.
  • Food and Drug Administration (FDA): The U.S. federal agency responsible for regulating food, drugs, and medical devices.
  • Paradoxical Adipose Hyperplasia (PAH): An increase in fat volume in the treated area after cryolipolysis.
  • Noninvasive: Procedures that do not require incisions into the body or removal of tissue.
  • Body Contouring or Body-Contouring: Cosmetic procedures that alter the shape of the body to achieve a desired appearance.
  • SculpSure: A non-invasive laser treatment for fat reduction.
  • Visceral Fat: Fat located within the abdominal cavity, surrounding internal organs. This fat is not treatable with CoolSculpting, which targets the “white fat” or subcutaneous fat below the skin.
  • Microdermabrasion: A cosmetic procedure that exfoliates the top layer of skin to rejuvenate its appearance.
  • Clinical Trials: Research studies conducted with human volunteers to evaluate medical interventions.
  • Tummy Tuck (Abdominoplasty): A surgical procedure to remove excess skin and fat from the abdomen and tighten muscles.
  • Obesity: A medical condition characterized by excessive body fat that may impair health.
  • Adipose Tissue: Body tissue that stores fat, providing insulation and energy reserves.
  • Interstitial Cells: Cells found in the spaces between organs and tissues that perform various functions.
  • Zeltiq Aesthetics: The original company that developed CoolSculpting technology.
  • Cryolipolysis Treatments: Procedures that use cold temperatures to reduce fat by destroying fat cells.
  • Bra Fat: Excess fat that accumulates around the bra area, often targeted for cosmetic procedures.
  • Hypertrophy: An increase in the size of an organ or tissue due to the enlargement of its cells.
  • Breast Augmentation: A surgical procedure to increase breast size, often involving implants.
  • Preadipocytes: Precursor cells that can differentiate into fat cells under certain conditions.

Does paradoxical adipose hyperplasia go away?

Paradoxical adipose hyperplasia is not physically dangerous, but it will not go away without treatment. Typically, patients have to wait up to six to nine months for the fat in the affected area to soften enough to be removed safely using liposuction—otherwise, there is a risk that PAH could recur. 

If you have had a CoolSculpting procedure and feel you may be experiencing the “stick of butter” side effect, it is important to inform your provider so that they can examine the area and recommend next steps.

Who is prone to paradoxical adipose hyperplasia?

Studies have not found any specific population to be more prone than another to developing this side effect.

References »

Jalian HR, Avram MM, Garibyan L, Mihm MC, Anderson RR. Paradoxical adipose hyperplasia after cryolipolysis. JAMA Dermatology. 2014 Mar;150(3):317-9. doi: 10.1001/jamadermatol.2013.8071. 

Singh SM, Geddes ER, Boutrous SG, Galiano RD, Friedman PM. Paradoxical adipose hyperplasia secondary to cryolipolysis: An underreported entity? Lasers Surg Med. 2015 Aug;47(6):476-8. doi: 10.1002/lsm.22380. 

Ponga-Manso M. Ultrasound assessment of abdominal adipose panniculus in patients treated with a single session of cryolipolysis in a clinical setting. Journal of Cosmetic Dermatology. 2022 Jan;21(1):307-315. doi: 10.1111/jocd.14597. 

Hetzel J, Awad N, Bhupalam V, Nestor M. Cryolipolysis in the United States-Review of the clinical data. Journal of Cosmetic Dermatology. 2023 Nov;22 Suppl 3:8-14. doi: 10.1111/jocd.16029. 

Kelly, Michael E. M.D.; Rodríguez-Feliz, Jose M.D.; Torres, Carolina M.D.; Kelly, Emma B.A. Treatment of Paradoxical Adipose Hyperplasia following Cryolipolysis: A Single-Center Experience. Plast Reconstr Surg 142(1):p 17e-22e, July 2018. | DOI: 10.1097/PRS.0000000000004523 

Hwang IC, Kim KK, Lee KR. Cryolipolysis-induced abdominal fat change: Split-body trials. PLoS One. 2020 Dec 29;15(12):e0242782. doi: 10.1371/journal.pone.0242782. 

Resende L, Noites A, Amorim M. Application of cryolipolysis in adipose tissue: A systematic review. Journal of Cosmetic Dermatology. 2022 Oct;21(10):4122-4132. doi: 10.1111/jocd.15265.

Murphrey M, Garibyan L. Cryolipolysis: The future of cryolipolysis. Journal of Cosmetic Dermatology. 2023 Nov;22 Suppl 3:37-47. doi: 10.1111/jocd.15985. 

Andreas Nikolis, Kaitlyn M Enright. A Multicenter Evaluation of Paradoxical Adipose Hyperplasia Following Cryolipolysis for Fat Reduction and Body Contouring: A Review of 8658 Cycles in 2114 Patients. Aesthetic Surgery Journal, Volume 41, Issue 8, August 2021.

Kalos Medical Spa stands behind CoolSculpting

Kalos Medical Spa is led by female plastic surgeon Dr. Emily Kirby. Her medical aesthetics team has many years of experience, and all of our staff who perform CoolSculpting are trained in best practices. Our licensed physician assistant Marianita Vela is a former Allergan Medical Institute Coolsculpting Faculty Trainer.

If you would like to learn more about CoolSculpting or any of the state-of-the-art services we offer for your skin, face, and body, please contact our Fort Worth med spa today at (817) 292-4200.


  • Alan
    January 2, 2024

    Well I had cool sculpting done on a small area in lower belly and it looks much worse now and it’s been 16 weeks. I now have a deformed stomach. I have to assume I am one out of the 4000 you wrote about getting PAH.

    • Reem
      February 3, 2024

      Is it treated now or the same?


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