The cellulite, particularly visible on the thighs and buttocks, is believed to result when subcutaneous adipose tissue protrudes into the lower reticular dermis, thereby significantly modifying the dermo-epidermis junction and creating irregularities at the surface. The biomechanical properties of epidermal and dermal tissue may also influence severity. This phenomenon located principally in the tights, abdomen and buttocks is characterised giving a spongy aspect of the skin. It can be associated with water retention and fibrose. The changes of the skin by the adipose tissue induce the changes of the biomechanical properties of the dermis.
The slimming products do not aim to make women lose weight, which would be outside the scope of a cosmetic product, but to locally reshape the tissues to tone up and tighten in the lower body (stomach, hips, buttocks, legs) or upper arms, as well as to reduce the appearance of cellulite. Although cellulite which is a natural phenomenon, is often considered negatively and can affect the body image and self-esteem of those who have it to varying degrees. Aqueous cellulite is often located in the inferior members: thighs, ankles, and calves. In the hypodermis, when the adipocytes are growing, they are compressing against each other’s, leading to a disruption and the slowing down of the venous and lymphatic circulation, called the vascular stasis.
Since more than 50 years, the slimming products market continues to increase. The beauty industry is constantly trying to satisfy the consumers with new techniques, new actives, and new products. The weight loss market represents almost 2.5 billion euros per year, and, in 2021, the annual growth rate was estimated at 7%. Multiple factors are causing this market evolution: changes in lifestyle, the beauty standards maintaining the cult of a slender and toned body, the nutritional trends. Today it is estimated that 90% of women have cellulite. Weight loss and cellulite products are often seen to counter this, or as a boost with the right changes in lifestyle.
The variety of the product offering in the slimming category of cosmetics is important with every type of formulation such as cream, gel, clothes, supplements, and even patch and with a large range of targets: weight loss, water retention and circulation, skin irregularities, appetite suppressant, fat sensors, cellulite, and even flat stomach.
But there are also many treatment techniques used by the women at home with specific medical devices targeting lymphatic drainage and body massage, like the WellBox (LPG), Luna 4 Body (Foreo), Silk’n Silhouette (Silk’n) and many more. In beauty institute: cryolipolysis, also called cryotherapy, radiotherapy, ultrasounds, manual massage among other. Some devices used are CelluM6 Alliance (LPG), DiaSculpt (Corpoderm) among other.
The clinical evaluation of the treatment efficacy of slimming products objectivates quantitatively and qualitatively, at the surface or deeply, the body morphology, the skin topography, the state of the dermis and hypodermis and the water flow of the skin. The inclusion of the subjects is a key point of this type of evaluation to minimise the inter-individual variations. Investigators will specifically pay attention to the hormonal criteria.
The consumer tests and the neurosensory evaluations can be a good way to evaluate the global effects of the personal care on the silhouette, the texture and aspect of the skin, the volume of the legs and the stomach.
Worldwide, in 2023, nearly 2.6 billion people are affected by obesity, which represent 32% of the population. In France, in 2019, 17% of the population was considered obese, or 8 million people.
So, if cellulite known as “orange peel”, and overweight is an increasingly common problem, who is most likely to be affected? Only 2% of men have cellulite, for almost 90% of women. First, the cellulite is touching gynoid regions of the body: thighs, waist, hips, making women most likely to have cellulite. Also, the woman body contains almost twice more adipose cells than the man body, and those cells are larger, making them easier to grow. In fact, adipose tissue represents 25% of women’s body mass, against 15% for men. The cellulite is mainly caused by hormones, so pregnancy, breastfeeding, puberty, menopause can have an impact on cellulite. Cellulite can also be caused by other factors: it can be hereditary, or due to a lack of exercise. Also, women’s skin is thinner than men’s, causing the adipose tissue to be more visible.
There are 3 types of cellulites: aqueous, adipose, or fibrous. Aqueous cellulite is due to water retention and poor circulation. Adipose cellulite is due to an excess of adipocytes, and fibrous cellulite is due to the fibrosis of the tissue.
To be able to verify the efficiency and claims of slimming products, you must identify the visual and tactile characteristics of cellulite. It is first known for the orange peel aspect. If the adipocytes, cells of the hypodermis, are stocking more fat than they are burning, it is causing them to grow, creating a disruption of the hypodermis and dermis, and generating this skin roughness aspect.
Skin may also show vascular problems, due to water retention. The adipocytes are preventing the evacuation of toxins and water. This can cause telangiectasias to appear, especially on the legs.
At touch, cellulite might feel cold because of circulations problems, but it may also cause pain, when pinching for example. This is the case when there is a fibrosis: the sclerosis and stiffening of collagen fibers and conjunctive septum. Personal care products offering an efficacy on the skin biomechanical properties are often linked to slimming claim category. These products are associated to various functionalities such as, lifting, firming, remodelling, sculpting, restructuring or tonic. The adipose tissue disruption is leading to a loss of firmness, and a less tone appearance.
Stretch marks are directly linked to body morphology phenomena and appear with weight and volume gain. They are a type of scar caused by the stretching or shrinking of the skin abruptly and too quickly. They are located around the hips, legs, but also breast or even abdomen, among other. When affected with stretch marks, the skin loses elasticity.
Slimming products often claims to influence those visual and tactile symptoms that most bother people with cellulite problems. It is important to understand that cellulite is complex occurrence and involves extended use of topical treatments, mechanical stimulation via massages besides adopting an active lifestyle.
What are the present methods and measurement devices to characterise on human the changes of centimetric loss and cellulite decrease?
Body morphology
- Scores by experts: 2 scales for body images (Gardner and al.), Body shape Questionnaire (Rousseau and al.), Body-image assessment scale (Thompson and al.)
- Cellulite grading:
- Hexsel et al (2009) is a validated photo numeric scale with excellent reliability and internal consistency based on 5 morphologic aspects: number of depressions, depth of depressions, clinical morphology, extent of skin laxity, flaccidity, or sagging.
- Nurnberger-Muller classification guide. Each variable is graded using three grades:
–Grade 1 or mild: “orange-peel” appearance, with superficial depressions (1 to 5), slightly “draped.”
–Grade 2 or moderate: medium-depth depressions, a “cottage cheese” appearance, moderately draped.
–Grade 3 or severe: “mattress” appearance, deep depressions (>10), severely draped.
- Centimetric measurements: circumference by a tape measure or a laser
- 2D imaging using cameras or video for multidimensional qualitative and quantitative evaluation and a special bench associated with data treatment.
- 3D imaging
- Stereo vision system, camera, or video for multidimensional qualitative and quantitative evaluation in 3D and a special bench, associated with data treatment and modelling: AEVA 4D, Dermatop (Eotech), ColorFace (Newtone), HeadScan (Orion), Vectra XT, VectraWB360, Primos, Olé, Observ 320, BodyScan 3D.
- Fringe projection and data treatment.
As Mr Edouard Macé, CEO of EOTECH, explained “Of course, measuring body on a very reproducible way is always a challenge taking care of breathing and volunteer global position while scanning, that is why their software provides control steps to produce the best results. The data analysis of AEVA system consists of to extract some body part to calculate volume and circumference changes. They also calculate the global deviation in pseudo colour to illustrate the change in volume.”
Cellulite aspects
- Clinical visual and tactile scores by skin experts: Scores by experts of the orange peel appearance, skin rugosity and elasticity: mechanically accented microrelief of thigh skin (Perin and t al.), photo scale of Skin roughness using oblique light (Bielfeldt and al.), photo numeric cellulite severity scale (Hexsel and al.)
- Global surface aspect of the skin: SpectraCam, SkinCam, NomadCan, Image acquisition and analysis system, C-Cube, DermaTOP, Antera 3D, Videometer, EvaSurf, TiVi 80, TiVi 60, DermaLab VisioScope, VisioFace, VisioScan, Epsilon, AEVA-HE-M, and all videomicroscopes…
- Surface topography analysis by Silflo print, photo with oblique light, fringe projections. In-vivo fringe projection allows fine measurements of:
- the skin roughness Sa (μm) in relation to the smoothing of the relief,
- the maximum amplitude of the surface St (μm) associated with dimpling,
- the volume (mm3) also reflecting the presence of dimples.
- Hypodermis analysis measure of the thickness and density and evaluation of the invagination of the hypodermis in the equivalent of the dermis.
- Ultrasound (5–10 MHz): DUBSkinScanner (Eotech), Dermascan (Cortex), Dermcup (Atys Medical), UltraScan (C+K)
- MRI: quantitatively evaluation of the fatty noddles
- Microscopy: Confocal with, Vivosight Dx (VivoSight); Raman Spectroscopy: (RiverD); LC-OCT (Damae Medical); Skin Barrier and blue light TEM, VivaScope (Mavig)
- NIR: MPT Flex Optical Multiphoton Tomography (JenLab)
Biomechanical properties of the skin
Direct biometrological assessments are designed to measure the elasticity and the firmness of the dermis through various instrumentations that enable quantification on several regions of the face and the body.
A real-time deformation using several techniques -ballistometry, suction, indentation, or air flow- is implemented one or several times on the skin surface. Then, the biomechanical behaviour induced is measured trough optical or fringe projection principle.
- Suction
- Cutometer and Cutiscan (C+K)
- Elastimeter and Skinfibrometer (Delfin)
- Dermalab Elasticity (Cortex)
- SkinFibroMeter (Delfon Technologies)
- Ballistometry: Ballistometer (Dia-Stron)
- Indentation: Indetometer (C+K)
- Airflow
- Dynaskin II (Eotech)
- SkinFlex (Orion)
- WaveSkin and UnderSkin (LTDS)
Microcirculation
Cellulite is generally related to alterations in microcirculation leading to a decrease in thermal emissivity. The application of specific active ingredients coupled with the action of the massage allows a revival of the cutaneous microcirculation associated with an increase in the surface temperature.
- AB TiVi 700 and Tivi 8000 (Wheelsbridge)
- Capillaroscope
- Laser Doppler …
Skin thermography
This measure enables the thermal distribution analyser due to non-contact infrared measurements.
- DermaLab Temperature (Cortex)
- Evatherm (Eotech)
- Soft Plus (Callegari)
SLIMMING CLAIM SUBSTANTIATION
IN VIVO INSTRUMENTAL AND BIOMETROLOGICAL ASSESSMENTS*
| Studied effect | Methods and Devices |
| Biomechanical properties | Cutometer, Cutiscan, Indentometer IDM800 (C+K), Dynaskin II (Eotech), SkinFlex (Orion), DermaLab Elasticity (Cortex), Elastimeter, Ballistometer, Easystiff, MyotronPRO, Soft Plus, WaveSkin, Underskin, SkinFibroMete |
| “Body morphology & Volume” | ColorFace (Newtone), AEVA-HE, Dermatop-HE (Eotech), HeadScan (Orion), Vectra XT, VectraWB360, Olé, Primos, Observ 320, BodyScan 3D… |
| “Relief & Topography” | AEVA-HE-S, Dermatop-HE, EvaSKIN-S5, (Eotech), ColorFace (Newtone technologies), Visioscan VC 98, Skin-Visiometer, Visioline/Quantirides (C+K), Quantirides, (MONADERM), Antera 3D (Miravex),C-Cube (Pixience), Vivosight Dx (Vivosight), TiVi 90 (Wheelsbridge), Clarity 3D, PrimosLite- 3D-Pico- Premium |
| Skin surface | SpectraCam, SkinCam, NomadCam, Image acquisition and analysis system (Newtone), Epsilon (Biox), Dermatop-HE, AEVA-HE-M, EvaSURF (Eotech), Visioface and Visioscan (C+K), C-Cube (Pixience), Antera 3D (Miravex), TiVi80, TiVi 60 (Wheelsbridge),DermaLab Videoscope (Cortex), Clarity 3D Mini, Neo Voir II, SIAScope, JYFEL, Visia-CR, VEOS HD2-DS3, Soft Plus, and all videomicroscopes.. |
| Microcirculation | TiVi 8000, TiVi 700 (Wheelsbridge), Laser Doppler Imager, Laser Doppler Moor, Laser Doppler Frequencer, Capillaroscope, Laser Doppler Blood FlowMeter, RSOM Explorer |
| Water retention | Raman Spectroscopy, DeepLive LC-OCT |
| Thermography | EvaTherm (Eotech) |
| “Skin strucure, Dermis size & Shape” | Ultrascan (C+K), Vivosight Dx (Vivosight), DermaScan, DermaLab (Cortex), DUBSkinScanner 33, DUBSkinScanner 50 (Eotech), Skin barrier and blue light [TEM] (Microscopy Services), Vivascope, Dermcup, Ultrasound WED-2018, MPT Flex Optical Multiphoton Tomography, Raman Spectroscopy, DeepLive LC-OCT |
| Metagenomic | Genomic, metabolomic, and proteomic analysis using MS/MS-16S rRNA-PCR (Phylogene) … |
| Global Aspect | – Visual and tactile objectivation with Scoring by technician experts and dermatologists using specific scales and photos, – Consummer Tests to evaluate the level satisfaction of the treatment – Sensory analysis by trained panels or naïve subjects, – Neurosensory: Tailor-made “emotiona” l protocol using physiological evaluation methods (heart rate, conductance …), psychological (unconscious perception…) and behavioral (facial expression and gestures…) scientific and self-evaluation questionnaires. |
Global assessments
For the slimming efficacy, the auto-evaluation with a use test questionnaire or a quality of life one, gives a very interesting information of the treatment performance perceived by the consumers.
The multiparametric study is a great approach of this claim crossing results from consumer insights, scores by experts and metrology.
Please retrieve all the methods by claims in table 1.
In conclusion, the preliminary discussion with the CROs to design the study defining the timeline, duration, conditions of use of the products, inclusion criteria, instrumentation choice, among other, seems to be essential to define the best protocol to support the claim substantiation. Moreover, the evolution of technology in the no contact probe, the nomad and deported instrumentation, the neurosensory perspectives, the data acquisition, and treatment with the use of I.A algorithm may give new direction of non-contact and optical solutions. Today, the “must have” is the illustrative results associated with quantitative and figures to give the best performance proof to the consumers.
On the clinical testing platform, you can find for the claims: slimming, anti-cellulite, anti-orange skin:
- 68 methods with 50 instrumental ones
- 148 testing laboratories located in 38 countries.
- 50 measurement devices offered by 27 instrumentation manufacturers.
