How Does CoolSculpting Work?

CoolSculpting is a fast-growing non-invasive cosmetic procedure that can selectively remove unwanted fat from many parts of the body. It uses precisely controlled cooling pads to cool fat cells down to a temperature that kills them, while leaving adjacent skin cells undamaged.

This article explains the history of CoolSculpting, how it’s able to achieve remarkably effective results, and which patients are the best candidates for the procedure.

The History of CoolSculpting

The origin of CoolSculpting is due to the curiosity of two Harvard Medical School dermatologists. Drs. Dieter Manstein and R. Rox Anderson observed that children who ate many frozen popsicles were apt to develop dimples in their cheeks. There’s even a medical term for this condition: Popsicle Panniculitis. Further investigation (#1) showed that fat cells are more sensitive to low temperatures than other skin cells, and that cooling then down to near freezing can actually kill off the fat cells.

This observation would not have been so important, were it not for one other characteristic of fat cells – unlike most other cells in the body, fat cells do not regenerate. This means that once eliminated, fat cells will not grow back.

Drs. Manstein and Anderson formed a company (EHR International) to research the most effective ways to cool fat cells, and to determine which parts of the body could most effectively be treated. Zeltiq Aesthetics acquired the technology in 2010, and further developed it. More recently Allergan acquired Zeltiq in 2017; they have continued to develop CoolSculpting technology and market it to licensed healthcare professionals.

As of 2022, Zeltiq have stated that over 11 million CoolSculpting procedures have been performed worldwide.

What is CoolSculpting, and How Does it Work?

CoolSculpting is the name given to the procedure developed by Zeltiq. The procedure involves cooling unwanted fat deposits to a precise low temperature, which causes the targeted fat cells to crystallize (or “freeze”), without damaging any adjacent cells.

The process of freezing fat cells is known as cryolipolysis. Lipolysis is the name given to the natural mechanism by which the body breaks down fat cells; the prefix “cryo” indicates the use of low temperatures. Cryolipolysis occurs at temperatures of between -1°C and 4°C (between 30°F and 39°F); CoolSculpting actually applies temperatures several degrees cooler (depending on the depth of the fat deposits) to penetrate beneath the skin’s surface.

This cooling process damages the fat cells, which causes then to progressively shrink and die after the procedure is complete. Unlike liposuction, there is no surgery and little downtime. This process continues after they return to their normal temperature. The body naturally and gradually absorbs and eliminates these dead fat cells following treatment, resulting in a reduction in the size of the treated area.

Results will start to be visible in as little as three weeks after treatment; full results may take two or three months to fully develop.

How Effective is CoolSculpting?

CoolSculpting can remove anywhere up to 20% or 25% of fat cells in the targeted area in a single treatment. This amount will vary according to the body area being treated, the patient’s body type, and the skill of the person performing the procedure. Multiple treatments can increase this percentage, and depending on the area being targeted, it may ultimately be possible to achieve 30% or more fat reduction.

It’s important to have appropriate expectations – your practitioner should give you an estimate of the results achievable for your particular situation after one or more treatments. This will, of course, depend on your body type and the areas being treated, but also on your lifestyle, your diet, and the amount of exercise you perform. Research indicates success rates in 86% of treated patients; patient satisfaction with CoolSculpting also rates higher than other non-invasive techniques (#2).

Bear in mind that CoolSculpting should not be viewed as a way to lose weight – its purpose is to selectively remove unwanted fat deposits, allowing the contours of the body to be improved (hence the name “CoolSculpting”). Even though the treated fat cells won’t grow back, other fat cells in your body will, if you continue with the lifestyle that originally led to excess fat accumulation.

Which Body Parts can be Treated?

CoolSculpting is cleared by the FDA as safe for use on these body parts:

• Submental. The under-chin area, including double-chins.
• Submandibular (under the jaw).
• Abdomen.
• Flanks (“love handles”).
• Inner and outer thighs.
• Bra strap area.
• Upper arms.
• Beneath the buttocks (“banana roll”).
• Backs

The procedure has also been used “off label” on these areas:

• Calves and ankles.
• Inner knee.

The procedure is most effective when used on packets of excess fat in the above areas, particularly when these fat deposits have proven resistant to exercise and/or dieting.

CoolSculpting is not effective on fat deposits that occur in the body’s core. It’s most effective when used on fat deposits that lay closer to the skin surface, and particularly on fat deposits that can be physically isolated. Cooling fat deposits close to the surface down to the required temperature is relatively easy and low-risk. Attempting to cool deeper fat deposits down to the required level would be far harder and carry elevated risk.

CoolSculpting is also not a solution for loose skin – it can reduce fat cells but will not provide a solution for any skin laxity.

Long-Term Benefits

• CoolSculpting confers important long-term benefits, in particular:
• As the procedure is non-invasive, recovery time is almost eliminated.
• There are no scars or visible signs of any treatment.
• Fat loss is permanent, as treated fat cells cannot grow back afterwards.
• A skilled practitioner can ensure that results are balanced and natural-looking.
• Patient self-confidence is boosted by the procedure, which in turn increases their ability to control their diet, and also to maintain or increase their exercise levels.
• Fat cells are eliminated from the body using natural processes; this results in a very low level of side effects or complications after treatment.

How Does CoolSculpting Differ from Other Fat Reduction Treatments?

• CoolSculpting offers some very significant advantages compared to other ways of reducing fat, such as liposuction:
• CoolSculpting is a non-invasive procedure, hence the risk of infection or side effects is dramatically lower. Costs are also correspondingly lower.
• No need for anesthesia, with its associated risks and recovery time.
• Cryolipolysis is highly effective and safe; it makes use of the body’s natural mechanisms for eliminating dead fat cells from the body.
• Natural-looking results: fat elimination occurs naturally and gradually, so no sudden change in your appearance.
• CoolSculpting gives highly targeted results, allowing fat reduction exactly where you want it, and nowhere else.
• Zero downtime. No recovery time is needed after treatment, so there’s minimal impact to your daily schedule.
• Extremely low chance of any unwanted side effects.
• Guaranteed long-term results, as long as a healthy diet and lifestyle is maintained.

The CoolSculpting System

The CoolSculpting system hardware has evolved since its introduction. It now comprises the following elements:

Control Unit

The control unit uses a combination of thermoelectric and traditional refrigeration technology to chill liquid coolant down to the required temperature. The coolant then circulates to the applicator and back again. It’s also able to generate a low-pressure vacuum that can be used by various applicators to increase thermal coupling with the skin. The vacuum may also be used to help massaging the skin and fat cells after cooling.

The control unit display allows the exact parameters of each treatment to be input, and more importantly closely monitored and adjusted as necessary. The coolant is chilled to precisely -11 degrees Celsius. The temperature applied to the skin must be held to within +/- 0.5 degree Celsius for the treatment to be both safe and effective.

The control unit software ensures that the procedure is performed using the exact cooling temperature and duration required for optimum cryolipolysis to occur; it also constantly monitors the patient to ensure that no unwanted situations develop.

Applicators

Various applicators are used, depending on the area(s) of the body being treated. Applicators are either hand-held, or function when strapped to the body. Some applicators use vacuum to increase the thermal coupling with the body. Applicators are instrumented, and allow the controller to monitor the exact temperature being applied to the skin.

Thermal Coupling Gel

A special thermally conductive gel is applied to the applicators to ensure that they make perfect thermal contact with the skin, with no hot or cold-spots. The gel also protects the skin from cold burns during the procedure. They also serve to increase the effectiveness of the vacuum function, when it’s applied.

All aspects of the CoolSculpting device are subject to rigorous inspection by the FDA. In common with other medical devices, no change to the system hardware or operating software can be made without prior approval from the FDA.

CoolSculpting Applicators

The applicators (also called handpieces) used as part of the CoolSculpting procedure are each optimized for use on specific parts of the body; they’re typically rounded paddles in various sizes and shapes. The applicators are important part of the process – they’re designed to efficiently cool subcutaneous fat in specific parts of the body, many of which may be hard to reach.

• CoolMini: Designed to help reduce fat in small, difficult-to-treat areas, such as the double chin.
• CoolAdvantage Petite: Designed to target localized fat deposits on smaller areas of the body, such as the arms.
• CoolAdvantage Plus: Designed for use on larger areas, such as the abdomen and love handles.
• CoolSmooth Pro: Designed for use on body parts that typically have minimal pinchable fat, such as the outer thighs, and provides smooth and even fat reduction.
• CoolCore Advantage: Designed for use on the upper abdomen.
• CoolFit Advantage: Designed for use on the flanks and love handles.

Some applicators use suction to increase their cooling efficiency. The suction effect from a partial vacuum ensures good thermal transfer between the applicator and the body, and also helps increase blood flow to reduce discomfort. Some applicators have multiple heads to allow larger areas to be treated at the same time. Most contain curved and/or flexible components to better adapt to different body shapes. All applicators are used with a thermally conductive gel to ensure that cooling is applied evenly over the are being treated.

All applicators are designed to precisely control the temperature that’s applied to the targeted fat cells, to both increase the effectiveness of the procedure and to ensure that no unwanted damage is caused. The software that’s used to control the procedure is also rigorously inspected by the FDA, and is subject to the same approval process.

Safety Concerns

It’s normal to have concerns about any procedure, including non-invasive ones. Fortunately, CoolSculpting has a well-established record of minimal side effects, dating back for over ten years.

The CoolSculpting system contains many safeguards to ensure that each procedure is performed at the optimum temperature and over the appropriate time. The applicators are each designed to facilitate correct use on a particular body part. The best way to guarantee that the procedure goes smoothly and that you get the results you want is to ensure that the practitioner performing the procedure is medically qualified, appropriately trained, and highly experienced in use of the CoolSculpting system.

CoolSculpting has been cleared for use in the US by the FDA, and has received EU CE certification in Europe – both guarantees that the procedure has been extensively studied and found to be safe.

Having a board-certified physician available to supervise the process is the ultimate assurance that you’re in safe hands. You should have the opportunity to discuss any concerns you have with the supervising physician beforehand, and they should be able to address any concerns you have.

FDA Clearances

Zeltiq and Allergan worked with the US Federal Food and Drug Administration (“FDA”) to conduct extensive clinical trials into the safety and effectiveness of the CoolSculpting procedure, resulting in the FDA granting clearance for use of the device.

The regulatory process has continued as the device has been enhanced and refined, and clearances have been obtained for use of the device in additional body areas.

This is the list of FDA clearances obtained since 2009 (#4); the list shows that Zeltiq remains committed to refining the CoolSculpting device, and is continuing to seek approval for its use in new body areas:

Date	FDA 510(k) Number	Description
2007	K072152	Juniper Dermal Cooling Device cleared for use in pain management.
2008	K080118	Zeltiq Dermal Cooling Device cleared for use with a massaging vacuum applicator for local anesthetic, to relieve discomfort, improve circulation, and reduce cellulite.
2010	K080521	Cleared for use on Flanks (love handles).
2012	K120023	CoolSculpting cleared for use on flanks (love handles) on patients with BMI of 30 or less. Cleared for use on abdomen.
2014	K133212	Cup and belt applicators cleared for use. Cleared for use on the thighs.
2015	K142491	Additional flank treatment parameters cleared.
2015	K151179	Cleared for use in the submental area, for ages 22 through 65.
2016	K160259	Cleared for use on abdomen, flanks, back, inner thighs, lateral thighs, anterior thighs, submental, and banana roll areas.
2016	K162050	CoolAdvantage applicator cleared (CoolMini with interchangeable contours). Cleared for use on upper arms.
2017	K171069	Cleared to use new CoolAdvantage Plus and CoolAdvantage Petite applicators, and new CoolAdhesive Pad and CoolAdhesive Plus Pad gelpads.
2017	K172144	Cleared for use on lax tissue in the submental area.
2018	K181740	Cleared for use in submental and submandibular areas with patients having BMIs under 46.2.
2019	K183514	Next generation system with enhanced cooling system cleared.
2020	K193566	Zeltiq CoolSculpting cleared for simultaneous use with dual applicators.
2021	K212707	Zeltiq CoolSculpting cleared for use on the abdomen. C150 Curved applicator cleared.

These various clearances are the result of rigorous supervised clinical trials – they were designed to prove the safety of each procedure, and its effectiveness over both short and long terms. FDA clearances may come with various caveats, such as limitation on the age of qualifying patients, or their BMI. CoolSculpting is currently the only cryolipolysis device cleared for use by the FDA in the US.

Some FDA clearances are also tied to specific variants of the CoolSculpting machine (including its applicator), hence the repetition in some cases.

Note: FDA “clearances” are not the same as “approvals”. The FDA only issues “approvals” when use of the device or procedure is considered high risk. Clearances are given for low-risk non-invasive cosmetic devices like CoolSculpting.

What Makes Someone a Good or Bad Candidate for CoolSculpting?

A good candidate for CoolSculpting would exhibit the following characteristics:

• having fat deposits that have stubbornly resisted exercise and dieting.
• has reasonable expectations.
• is looking for a safe, effective alternative to liposuction or surgery.
• has good skin elasticity and good skin tone.

Negative characteristics include:

• morbidly obese (BMI > 46).
• poor skin tone and elasticity.
• looking for an easy way to lose weight.
• expects to remove all unwanted fat.
• has sensitive skin or rashes in the are being treated.
• suffering from cryoglobulinemia, paroxysmal cold hemoglobinuria, or cold agglutinin disease.

Possible Side Effects

CoolSculpting can provoke a number of side effects (#3) in the treated area, all of which are temporary.

You may experience the following during treatment:

• Sensation of skin being pulling.
• Intense cold, with possible tingling, aching, or cramping.

Immediately after treatment:

• Redness and a feeling of firmness.
• Mild bruising at the edges.
• Tingling and/or stinging.

One to two weeks after treatment:

• Redness, bruising, swelling.
• Tenderness, cramping, aching.
• Skin sensitivity, itching, numbness.
• Back-of throat fullness sensation after submental and submandibular treatments.

There is a very small risk of developing PAH (Paradoxical Adipose Hyperplasia) after treatment. This condition can result in some fatty tissue thickening and expanding.

Finding the Best Practitioner in California

The FDA determined that the CoolSculpting device is a Class II medical device. This means that it can only be operated by licensed healthcare professionals, including suitably trained and certified doctors, nurses, and physician assistants. In California a licensed and trained aesthetician can only use the device when supervised by a physician.

You should look for a practitioner who is both medically trained and highly experienced in performing CoolSculpting procedures. In common with all other non-invasive procedures, using a trained and experienced practitioner will lead to better outcomes and fewer unwanted side-effects.

Your practitioner should also give you plenty of opportunity to ask as many questions as you need to set your mind at rest. They should also help set reasonable expectations, and ensure that you have no medical conditions that might lead to complications. They will of course discuss the financial aspects of the procedure or procedures. Don’t compromise on a practitioner who doesn’t set you at ease, or who appears too rushed to answer all your questions.

References

1. Selective cryolysis: a novel method of non-invasive fat removal.
   Dieter Manstein, Hans Laubach, Kanna Watanabe, William Farinelli, David Zurakowski, R Rox.
   Lasers Surg Med. 2008 Nov; 40(9):595-604.
   https://pubmed.ncbi.nlm.nih.gov/18951424/
2. Cryolipolysis for noninvasive body contouring: clinical efficacy and patient satisfaction.
   Nils Krueger, Sophia V Mai, Stefanie Luebberding, and Neil S Sadick.
   Clin Cosmet Investig Dermatol. 2014; 7: 201–205.
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4079633/
3. CoolSculpting Safety Information.
   https://www.coolsculpting.com/pdfs/CSC125713-v3-CoolSculpting-Important-Safety-Information.pdf
4. FDA Clearances for Zeltiq CoolSculpting Devices.
   https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMN/pmn.cfm?start_search=1&productcode=OOK&knumber=&applicant=ZELTIQ%20Aesthetics%2C%20Inc%2E