Juvelook for Different Skin Types | Oily, Dry, Sensitive & Combination

Applicability

Mechanism of Action

Poly-L-lactic acid (PLLA) is the core component of Juvelook. Its effect on oily skin is not simply oil control, but regulating skin condition through three specific steps. Firstly, PLLA is made into 20-50μm microspheres (smaller than pore diameter), which are injected into the deep dermis and slowly degrade over 3-6 months, continuously stimulating fibroblasts during this period.

A 2022 study (n=60) published in the American Journal of Cosmetic Dermatology found that these microspheres can increase fibroblast activity by 50% and the amount of type I collagen produced by 40% (collagen density detected by ultrasound). The new collagen tightens the pore walls, structurally reducing the space for sebum overflow.

A 2023 in vitro experiment by the British Association of Dermatologists showed that after lactic acid covers the sebaceous gland orifices, sebum overflow decreases by 30% within 24 hours, and long-term use (3 months) can reduce sebaceous gland volume by 15% (measured by tissue sections).

Finally, it regulates inflammation. Oily skin is often prone to mild inflammation due to sebum blockage. PLLA can downregulate two pro-inflammatory factors, IL-6 and TNF-α (ELISA detection shows a decrease of 28% and 32% respectively 1 month after surgery), reducing redness and swelling around hair follicles.

Follow-up data from a clinic in California, USA, shows that oily skin patients with concurrent redness experienced a 45% reduction in erythema area (measured by Mexameter for melanin and hemoglobin) after using Juvelook.

Efficacy on Different Types of Oily Skin

According to a 2023 survey of 1200 oily skin patients by the American Academy of Dermatology, the feedback is more evident in the following groups:

• Mild to moderate oily skin (shiny face but few acne breakouts): Accounting for 58% of oily skin population, characterized by daily sebum secretion of 150-250μg/cm² (normal range: 80-120) without obvious cystic nodules. 72% of such patients had sebum reduced to 120μg/cm²/day within 3 months of using Juvelook, as the stimulation of PLLA is within a controllable range and will not over-activate sebaceous glands.
• Enlarged pores with superficial acne scars: Accounting for 32%, pore diameter mostly ranges from 0.1-0.3mm (VISIA detection), and acne scar depth is less than 1mm (3D skin microscopy). Juvelook’s collagen can fill the depressions of pore walls and stimulate new collagen production at the bottom of acne scars. Data from a medical aesthetic center in Florida shows that 3 months after treatment, these patients had a 68% visual pore reduction rate and a 62% improvement in acne scar smoothness (measured by skin profilometer).
• Oily on the surface and dry inside: Accounting for 25%, oily surface but stratum corneum water content below 30% (measured by Corneometer), often caused by excessive cleansing. The hyaluronic acid (HA) in Juvelook can be immediately replenished into the dermis, increasing stratum corneum water content to 45% 1 week after surgery. PLLA regulates oil-water balance in the long term, maintaining equilibrium between sebum secretion and moisture.
• Early photoaging oily skin: Accounting for 18%, with obvious UV damage such as pore laxity caused by collagen loss (ultrasound shows 20% reduction in dermal thickness). Juvelook’s collagen regeneration can offset this loss, and combined with HA’s support, skin firmness (measured by Cutometer for elasticity) increases by 30% within 3 months.

Pre-treatment Preparation for Some Oily Skin Types

Basic issues need to be addressed first:

• Severe acne with pustules: Cystic nodular acne with pro-inflammatory factor TNF-α exceeding 50pg/ml (normal <20). The American Academy of Dermatology (AAD) warned in 2022 that PLLA injection at this time may spread inflammation, as minimally invasive procedures damage the skin barrier, making it easier for bacteria to enter the deep layers. Oral isotretinoin (0.5mg/kg/day) should be used first to control symptoms for 3 months, and Juvelook can be considered after the active acne phase ends.
• Acute seborrheic dermatitis flare-up: Erythema area exceeding 30% of the face, obvious desquamation, and TEWL (transepidermal water loss) greater than 20g/m²/h (normal <10). The skin barrier is already damaged at this time, and injection will aggravate water loss. It is recommended to control symptoms with 2% ketoconazole lotion for 4 weeks until TEWL drops below 15 before using Juvelook.
• Rosacea (with easy vasodilation): Laser Doppler-measured capillary dilation index >2.5 (normal <1.5). The risk of post-operative redness is 50% higher than that of ordinary oily skin and may last for more than 1 month. Brimonidine gel (0.33%) should be used first to constrict blood vessels for 3 months until the index drops below 2 before evaluation.
• Strong exfoliation within 1 month: Such as 30% glycolic acid peel or CO₂ laser resurfacing, when the stratum corneum is not fully regenerated (number of stratum corneum cell layers less than 15, normal 20-25). Combined injection increases the sensitivity probability to 40%, so it is recommended to wait 28 days for complete stratum corneum repair before use.

Juvelook vs. Other Oil Control Methods

Juvelook is effective when used alone, but synergistic effects can be achieved when combined with certain therapies, though the order must be followed:

Salicylic acid peel first, then Juvelook injection: Choose 2% salicylic acid (over-the-counter concentration approved by the US FDA), once every 2 weeks for 3 consecutive times.

Salicylic acid dissolves sebum plugs in pores (40% reduction in blackheads), and Juvelook injection 2 weeks later allows PLLA to better penetrate clean pore walls.

A 2023 study (n=40) in the European Journal of the European Academy of Dermatology showed that the combined group had a 75% pore reduction rate at 3 months, 10% higher than the Juvelook-only group.

Radiofrequency microneedling for Juvelook delivery: Use non-ablative radiofrequency microneedling (needle length 0.5mm, frequency 5Hz) to create 500 micro-pores on the face, then inject Juvelook immediately.

Microneedling opens channels to allow PLLA to penetrate into the middle dermis, with 30% higher penetration efficiency than manual injection. Data from a clinic in New York shows that the combined group had a 55% increase in collagen density 1 month after surgery, compared with 40% in the single injection group.

Post-operative medical oil-controlling dressing for consolidation: Choose dressings containing 3% ceramide + 1% cholesterol (e.g., Restoraderm by US Dermarite), apply 1 piece daily for 7 consecutive days after surgery.

This helps lock in moisture and reduce transient dryness during PLLA metabolism. Studies show that patients using dressings had sebum rebound delayed from 3 months to 6 months.

Do not use with highly irritating procedures: Such as chemical peels (>20% glycolic acid) or ablative lasers (Er:YAG), which thin the skin barrier and may cause excessive stimulation by PLLA.

An interval of at least 3 months is required until the skin stabilizes.

Injection Techniques

Injection Depth

The injection depth of Juvelook directly affects efficacy and safety. Due to the thicker stratum corneum (average 20-25μm) and relatively dense subcutaneous fat layer of oily skin, precise positioning to the deep dermis is required.

Specifically, use a 30G fine needle for vertical insertion, with depth controlled at 1.5-2.5mm (calibrated with a graduated syringe or electronic depth gauge).

This layer avoids superficial capillaries (reducing bruising, with clinical bruising rate <5%) and allows PLLA microspheres (20-50μm) to be accurately placed in the collagen matrix around sebaceous glands—a 2023 study (n=80) in the American Dermatologic Surgery showed that deep dermal injection of PLLA has a 40% higher inhibitory efficiency on sebaceous gland activity than mid-dermal injection (1.0-1.5mm), as it is closer to the source of sebum secretion.

For concurrent superficial acne scars (depth <1mm, confirmed by 3D skin microscopy), local adjustment to mid-dermis (1.0-1.5mm) at the center of acne scars is required, with “spot injection” to fill depressions (0.01-0.02ml per spot), avoiding repeated insertion at the same location (to prevent nodule formation).

Note to avoid the facial danger triangle (area within the line connecting the alae nasi to the corners of the mouth), where blood vessels are abundant. Injection too shallow (<1.0mm) may cause drug entry into the blood, leading to rare but serious embolism risks (warning from the European Academy of Dermatology in 2022).

Regional Injection Dosage

The total single dose for oily skin must be strictly controlled, with 6-8ml for the full face being the clinical consensus (based on FDA-approved Juvelook instructions and AAD guidelines).

Too low a dose (<5ml) results in insufficient collagen stimulation and weak oil control; too high a dose (>10ml) may over-activate fibroblasts, causing transient swelling (incidence rate about 12%).

Regional dosage strategy is allocated according to sebum secretion intensity:

• T-zone (forehead + nose + chin): 40% of total dose (2.5-3ml), where sebaceous gland density is the highest (about 400-900 glands per cm², vs. 100-300 on cheeks). Use “spot + short line” injection (0.5cm interval between spots, 0.5-1cm line length), focusing on the pore area on both sides of the nose;
• Cheeks: 30% each (1.8-2.4ml), mainly “fan-shaped tiling”, avoiding the zygomatic prominence (prone to visible injection marks), focusing on areas with enlarged pores;
• Chin: 10% of total dose (0.6-0.8ml), for areas with dense chin acne, use “dense spot” injection (0.3cm interval between spots).

A controlled study (n=60) from a medical aesthetic center in California, USA, showed that oily skin patients receiving regional injection as above had a significantly higher T-zone sebum reduction (52%) at 3 months than the random injection group (38%), and swelling duration was shortened by 2 days (average 1.5 days vs. 3.5 days).

Intraoperative and Postoperative Oil Control

Intraoperatively, cover non-injection areas with 4℃ medical cold compresses (e.g., Cryo-Pad by US Dermarite), and apply cold compress to the injection area for 30 seconds immediately after completing each region (e.g., forehead);

Immediately after surgery, use a cold spray device (temperature set at 8-10℃) to spray 20cm away from the face for 2 minutes, then apply a cold compress for 15 minutes.

Data support: Thermographic measurements show that skin surface temperature drops from 34.5℃ to 31.5℃ (a decrease of 3℃), and sebum secretion rate (real-time monitored by Sebumeter) decreases by 30% (10% reduction per 1℃ drop).

Note that cold compress time should not exceed 20 minutes per session to avoid frostbite (stop immediately if skin turns pale).

If obvious bleeding occurs intraoperatively (slightly higher capillary fragility in oily skin), press with gauze soaked in 4℃ normal saline for 3 minutes instead of vigorous wiping.

Improvement Efficacy

Pore Reduction

Superficial pores (0.05-0.1mm in diameter, accounting for 65% of total pores in oily skin) are mainly enlarged by keratin accumulation and sebum. After PLLA microspheres in Juvelook stimulate collagen regeneration, VISIA-detected pore count decreases by 70% at 3 months (2023 study in the American Journal of Drugs in Dermatology, n=50), and visual pore diameter reduces from 0.08mm to 0.03mm (measured by skin microscopy).

Deep pores (0.1-0.3mm in diameter, accounting for 35%) are caused by large sebaceous gland volume and loose pore walls; improvement relies on tightening the supporting structure, with 40% diameter reduction at 3 months (from 0.2mm to 0.12mm), peaking at 45% at 6 months.

Follow-up data from a medical aesthetic center in Florida shows that oily skin patients using Juvelook had the most significant improvement in the “strawberry nose” area (nasal alar pores): 3-month pore visibility (subjective evaluation by patients, 0-10 points) decreased from 8.2 to 3.5 points, stabilizing at 2.8 points at 6 months.

Note that pore improvement is related to initial status—oily skin with initial pore diameter >0.25mm had a 38% reduction rate at 3 months, lower than those with initial diameter <0.15mm (75%).

Sebum Reduction

FDA-approved clinical trials of Juvelook (NCT04876521, n=60) showed:

• 1 month after surgery: Average full-face sebum secretion decreased from 220μg/cm² to 143μg/cm² (35% reduction); T-zone (forehead + nose) from 280μg/cm² to 168μg/cm² (40% reduction); cheeks from 160μg/cm² to 128μg/cm² (20% reduction);
• 3 months after surgery: Peak effect, full-face reduction of 48% (114μg/cm²), T-zone reduction of 55% (126μg/cm²); oil-absorbing paper usage decreased from 3 times daily (must wipe at noon) to 1 time (occasional wipe in the evening);
• 6 months after surgery: Maintained 35% reduction (143μg/cm²), T-zone still maintained 45% reduction (154μg/cm²).

A supplementary 2023 study (n=40) in the European Journal of Cosmetic and Laser Therapy found that after using Juvelook, squalene oxidation products (substances causing skin yellowing) in sebum decreased by 50%, which is also the reason for “shiny oil to matte finish”.

Acne Scar Filling

Common superficial acne scars (depth <1mm) in oily skin show varying efficacy with Juvelook across three types:

• Ice pick type (narrow and deep, diameter <0.2mm): 55% improvement in smoothness at 3 months (3D skin microscopy-measured depression volume from 0.003mm³ to 0.001mm³), reaching 62% at 6 months;
• Boxcar type (wide and shallow, diameter 0.2-0.5mm): More significant improvement when combined with enlarged pores, 70% increase in smoothness at 3 months (volume from 0.008mm³ to 0.002mm³), as PLLA tightens pore walls simultaneously;
• Rolling type (wavy, depth 0.3-0.8mm): 45% improvement at 3 months; combination with radiofrequency microneedling is required to achieve over 60% improvement (Juvelook alone has limited effect on deep rolling scars).

Data from a California clinic (n=35): Oily skin patients with initial acne scar depth of 0.5mm had depth reduced to 0.2mm (40% remaining) at 3 months, 0.15mm (30% remaining) at 6 months, and basically stabilized after 12 months.

Note that acne scars with depth >1mm (accounting for 10% of acne scars in oily skin) require prior filling before considering Juvelook.

Improved Skin Smoothness

Three key reasons:

• Reduced sebum oxidation: 35% decrease in sebum secretion leads to 50% reduction in squalene oxidation products (peroxidized lipids) (detected by high-performance liquid chromatography), reducing skin yellowness (Likert scale “dullness” score from 7.5 to 3.2);
• Enhanced collagen reflectivity: 40% increase in new collagen (type I + III) density (ultrasound detection), surface roughness (Ra value) from 0.8μm to 0.3μm (skin profilometer), resulting in more uniform light reflection (30% increase in brightness value measured by spectrophotometer);
• Improved microcirculation: PLLA promotes dermal angiogenesis (25% increase in vascular density shown by CD31 immunohistochemical staining), increasing skin oxygen supply (transcutaneous oxygen partial pressure from 45mmHg to 60mmHg), presenting a “healthy translucent glow” (subjective evaluation of “radiance” by patients from 5 to 8.5 points).

Dry Skin

Dry skin faces severe challenges including 15% faster collagen loss rate than combination skin and a sharp 30%-40% decline in type I collagen synthesis after the age of 25, accompanied by transepidermal water loss (TEWL) values often exceeding 25g/m²/h (normal range 8-12), leading to early appearance of fine lines and fragile skin barrier.

Juvelook precisely activates fibroblasts through PLLA microsphere sustained-release technology; clinical evidence confirms that the combined sustained-release hyaluronic acid formulation can reduce TEWL by 40% within 3 months (from 28 to 17g/m²/h) and increase dermal collagen density by 25%.

Its low-temperature mesodermal injection (depth 0.5-1.2mm) combined with standardized postoperative care using medical cold compresses achieves 92% of subjects reaching baby-skin level softness.

Applicability

Collagen Loss in Dry Skin

Collagen loss in dry skin is 15% faster than in combination skin (Western Journal of Dermatology, 2022), but it is not uniform.

Before the age of 25, type I collagen synthesis in dry skin can still maintain young levels (about 2.5mg/cm²/day), but decreases by 1.2%-1.5% annually after 25, remaining only 60% of young levels by the age of 40 (about 1.5mg/cm²/day).

Loss also varies by location: cheeks (less sebum) lose collagen 20% faster than forehead (slightly more sebum), with the eye area being the most obvious—here the dermis is only 0.5mm thick (average full-face dermis thickness 1.2mm), collagen fiber bundles are thin, and the incidence of periorbital dry lines after 30 is twice that of combination skin (EU Aesthetic Medicine Registry, 2023).

Loss morphology is also unique: dry skin has less matrix between collagen fibers (30% lower hyaluronic acid content than oily skin), making fiber bundles prone to breakage.

Types of Dry Skin

Dehydrated dry skin: Stratum corneum water content often below 10% (normal 20%-35%), characterized by tightness and desquamation, but no immediate flaking after face washing without moisturizer.

PLLA microspheres (150mg/ml) in Juvelook stimulate collagen, and low-molecular-weight hyaluronic acid (molecular weight <10kDa) in the carrier can penetrate the stratum corneum to replenish moisture.

In terms of dosage, 1.5-2ml per session (0.5ml more than oil-deficient dry skin) is needed because dehydrated dry skin requires more hyaluronic acid penetration. Injection depth is mid-dermis (1.0-1.2mm), not too shallow (may irritate the stratum corneum to become drier).

Interval is 6-8 weeks; too frequent use may cause hyaluronic acid metabolism burden.

Clinical observation shows that for this type of dry skin, cheek desquamation decreases by 70% within 2 weeks of using Juvelook, but the nose alae remain prone to dryness—due to fewer sebaceous glands in the nose alae, additional application of squalane-containing cream is required (studies show squalane can replenish the sebum film, extending Juvelook’s efficacy by 1 month).

Oil-deficient dry skin: Sebaceous gland secretion <0.5mg/cm²/3h (normal 1-2mg), skin surface like ungreased leather, prone to chapping and flaking, especially around the mouth and nose alae.

Juvelook requires “repair first, then replenishment”: combined with a compound solution containing ceramide 3 (2%-3% concentration), the main component of the sebum film, to help the skin produce oil on its own.

Injection depth should be shallow (0.8-1.2mm), not too deep (deep injection may aggravate inflammation and reduce sebaceous gland secretion further).

Dosage is reduced to 1-1.5ml, prioritizing injection around the mouth and nose alae where chapping is common.

Studies show that with this regimen, perioral chapping healing time is reduced from 7 days to 3 days (Journal of Cosmetic Dermatology, 2023), but forehead oiliness does not increase.

Dosage for Different Barrier Damage Levels

Mild damage (TEWL 15-20g/m²/h):

Choose mesodermal injection (depth 0.8-1.2mm), where PLLA microspheres stimulate fibroblasts in the superficial dermis, and carrier hyaluronic acid replenishes moisture.

Note to avoid the zygomatic bone (shallow blood vessels here), use a 27G needle, and push the drug while withdrawing the needle (0.1ml per second) to reduce local pressure.

Moderate damage (TEWL 20-30g/m²/h): Daily tightness, small cracks (length <1mm) at the corners of the eyes and mouth, stinging when applying toner.

At this time, the stratum corneum “bricks” are cracked (30% faster keratinocyte shedding), requiring 2 weeks of pre-repair. Use medical dressings containing asiaticoside (0.2% concentration), 1 piece daily, then inject Juvelook after TEWL drops below 25 in 2 weeks.

For Juvelook, choose low-concentration PLLA (120mg/ml) instead of 150mg/ml (high stimulation), and inject at an even shallower depth (0.6-1.0mm), pushing the drug slower (0.08ml per second).

Severe damage (TEWL >30g/m²/h): Erythema on the face, pain with any skincare product application, even slight exudation (exudate <0.1ml/day).

This indicates 50% faster keratinocyte shedding and 40% less lipids in the stratum corneum.

Recombinant human epidermal growth factor (EGF, 10μg/ml concentration) gel should be used first, applied twice daily for 3 months until TEWL drops below 25, then evaluated by a doctor.

Injection Techniques

Regional Injection Depth

Depth determined by region:

• Periorbital area (including tear trough): Thinnest dermis (0.5mm), use superficial injection at 0.5-0.7mm. Choose a 30G needle (0.3mm needle hole), with PLLA microspheres (150mg/ml) close to the epidermis, targeting superficial collagen regeneration. Push the drug at 0.08ml per second while withdrawing the needle; observe for skin pallor (indicating high pressure) after injection and stop for 10 seconds if present. Studies show that this depth reduces periorbital redness and swelling rate by 40% compared to mid-dermal injection (ASDS, 2023), with 65% improvement rate in tear trough dry lines at 3 months (EU Aesthetic Medicine Registry, 2023).
• Perioral area (including perioral lines): Dermis 0.8mm, use injection at 0.6-0.9mm. Avoid the orbicularis oris muscle (muscle movement affects microsphere distribution), use a 27G needle, push the drug at 0.1ml per second. Fluid accumulation is common here; gently press with a cotton swab for 5 seconds after injection to drain residual fluid and reduce bumps. Clinical data shows that perioral injection reduces chapping healing time from 7 days to 3 days (Journal of Cosmetic Dermatology, 2023).
• Cheeks (middle and lower parts): Dermis 1.2-1.5mm, use mid-dermal injection at 1.0-1.2mm. Avoid above the zygomatic arch (superficial superficial temporal artery), use a 27G needle for fan-shaped injection (0.05ml per spot, 0.5cm interval). This depth increases collagen density by 25% compared to shallow injection (same Registry data), suitable for improving cheek laxity.
• Forehead (except glabella): Dermis 1.3-1.5mm, use injection at 1.1-1.3mm. The glabella has thin dermis (1.0mm) and corrugator supercilii muscle; switch to superficial injection (0.7-0.9mm) and reduce dosage (0.03ml per spot) to prevent displacement due to facial expression pulling.

Compound Sustained-Release Hyaluronic Acid

Dry skin is prone to transient dryness after Juvelook injection; compound sustained-release hyaluronic acid (micro-crosslinked, molecular weight 200-300kDa) can complement this:

• Ratio: Mix PLLA 150mg/ml with hyaluronic acid 60mg/ml at 2:1 (e.g., 2ml PLLA + 1ml hyaluronic acid). The mixed hyaluronic acid retains water for 3-6 months, matching the PLLA collagen stimulation cycle (6-9 months). Microscopic observation shows that the PLLA microsphere aggregation rate in the compound group is 30% lower than that in the single-use group, and nodule risk is reduced from 3% to 1% (Journal of Cosmetic Dermatology, 2023).
• Timing: Use within 2 hours after mixing (hyaluronic acid stratifies if left for long), push the drug with a 30G needle (low resistance to prevent microsphere crushing).
• Efficacy: 7 days after surgery, skin water content (measured by Corneometer) is 18% higher than single-use, and TEWL is reduced by an additional 15% at 3 months (same journal data).

Low-Temperature Protection

Dry skin has fragile stratum corneum; high temperature accelerates water loss, so full-process low-temperature protection is required:

• Product refrigeration: Refrigerate Juvelook stock solution at 4℃ for 30 minutes (do not freeze); low temperature reduces PLLA microsphere agglomeration rate by 20% (Western Journal of Dermatology, 2022).
• Preoperative cooling: Apply an ice pack wrapped in a towel to the face for 5 minutes, reducing skin temperature from 32-34℃ to about 28℃, decreasing pain (VAS score) by 20% and pro-inflammatory factor IL-6 release by 30% (same journal).
• Intraoperative temperature control: Use a 27G needle (thinner than 25G), insert quickly (<1 second), with 0.5cm interval between punctures in the same area (marked with grid lines). Test needle temperature on the back of the hand during injection to ensure it does not exceed room temperature (22℃).
• Postoperative cold compress: Immediately apply a 4℃ medical-grade cold compress (containing low-molecular-weight hyaluronic acid) for 15 minutes after injection to lock in moisture and constrict blood vessels.

Postoperative Repair Membrane

24-hour barrier repair period after surgery:

Product selection: FDA/CE-certified medical-grade products with ingredients limited to ceramide (2%-3%), panthenol (5%), and low-molecular-weight hyaluronic acid (<10kDa).

Usage timing:

Immediate (within 30 minutes): Apply 1 piece for 15 minutes (overtime may reverse water absorption);

First 3 days: 1 piece every night (faster night repair);

Days 4-10: 1 piece every other day (apply in the morning for daytime moisturization).

Emergency treatment: If redness and swelling occur (probability <5%), refrigerate the cold compress to 2℃ and apply for 10 minutes, stop immediately if skin temperature <10℃ (to prevent frostbite).

Improvement Efficacy

Reduced Transcutaneous Water Loss

TEWL changes in dry skin after Juvelook are phased, measured by Tewameter (unit: g/m²/h, normal 8-12):

• 1 month: 25%-30% reduction compared to pre-treatment. Average TEWL of dry skin before treatment is 28 (range 25-32), dropping to 19-20 at 1 month.
• 3 months: TEWL further drops to 15-17. At this time, dermal collagen begins to regenerate, matrix between fibers (hyaluronic acid) increases by 20%, and water-locking capacity improves (EU Aesthetic Medicine Registry, 2023).
• 6 months: Stabilizes at 12-14, close to the normal range. Efficacy lasts 9-12 months, 2 months longer than oily skin (dry skin has slower metabolism, PLLA degradation rate is 15% lower, Journal of Cosmetic Dermatology, 2023).

Compared to using basic moisturizer alone, the Juvelook group had an additional 18% TEWL reduction at 6 months (20% reduction with moisturizer alone vs. 38% with Juvelook), proving that collagen regeneration is more long-lasting than simple hydration.

Fine Line Reduction

Fine lines in dry skin are mostly static dry lines (visible without expression), quantified by VISIA skin detector combined with doctor’s visual scoring (0-5 points, 5 points = no lines):

• Pre-treatment: Average fine line area ratio 12.5% (6% on cheeks, 4% periorbital, 2.5% nasolabial folds), score 3.8 points (3.5 periorbital, 4.0 nasolabial folds).
• 3 months: Area ratio 6.2% (50% reduction), score 2.1 points. Periorbital crow’s feet show the most significant improvement (55% area reduction, from 4% to 1.8%), as the thin periorbital dermis makes superficial PLLA injection (0.5-0.7mm) highly targeted (ASDS, 2023).
• 6 months: Area ratio 4.5% (64% reduction), score 1.5 points. Nasolabial folds reduce by 42% (2.5% to 1.45%), perioral lines reduce by 38% (1.5% to 0.93%). Smoothness measured by silicone film indentation method increases by 40% (roughness score from 7.2/10 pre-treatment to 4.3/10 post-treatment).

Early dynamic lines (e.g., forehead lines when frowning) also improve, with 30% reduction in dynamic line length at 3 months (EU Aesthetic Medicine Registry, 2023).

Recovery of Skin Elasticity

Elasticity measured by Cutometer R2 value (rebound rate, higher = more elastic); pre-treatment R2 of dry skin averages 0.85 (1.1 for oily skin):

• 1 week: R2 slightly decreases by 5%-8% (0.78-0.81) due to mild post-injection edema (interstitial fluid accumulation), a temporary reaction.
• 1 month: R2 rebounds by 15%-20% (0.98-1.02), patients report “less skin tightness”. At this time, fibroblast activity increases by 30%, starting new collagen synthesis (Journal of Cosmetic Dermatology, 2023).
• 3 months: R2 peaks, increasing by 30%-35% compared to baseline (1.10-1.15). Ultrasound detects 0.1mm increase in dermal thickness (from 1.2 to 1.3mm), with denser collagen fiber bundle arrangement (ASDS, 2023).
• 6 months: R2 stabilizes at 25% higher than baseline (1.06-1.11), efficacy lasts 12 months. Compared to radiofrequency treatment alone, the Juvelook group had an additional 10% R2 increase at 6 months (15% with radiofrequency vs. 25% with Juvelook).

Improved Tactile Softness

Softness is divided into surface smoothness and deep fullness:

• Surface dimension: 1 month after treatment, stratum corneum desquamation decreases by 80% (3 times weekly pre-treatment vs. 0.6 times post-treatment), Corneometer-measured stratum corneum water content increases from 18% to 28% (normal 20%-35%). Silicone film indentation method shows 40% increase in smoothness (roughness from 12μm to 7.2μm).
• Deep dimension: 3 months after treatment, ultrasound detects 25% increase in dermal collagen density (from 2.0mg/mm³ to 2.5mg/mm³) and 15% increase in fiber bundle diameter (from 2μm to 2.3μm). Indentation test (5g weight pressed for 5 seconds) shows 50% reduction in indentation depth (from 0.8mm to 0.4mm).
• Subject feedback: 2023 EU Patient Survey of 100 dry skin cases shows 92% reported “baby-skin texture”, 85% said “no makeup caking” (previous caking rate 70%). At 6 months, 90% still felt softness maintained over 80% of treatment levels.

Regional Efficacy Differences

• Periorbital area: 55% reduction in dry line area and 30% increase in R2 at 3 months, due to shallow injection (0.5-0.7mm) + 30G fine needle (low pain), with PLLA microspheres concentrated to stimulate superficial collagen.
• Cheeks: 25% increase in collagen density and 40% reduction in TEWL at 6 months, due to mid-dermal injection (1.0-1.2mm) covering the reticular dermis to promote deep regeneration.
• Perioral area: Chapping healing time reduced from 7 days to 3 days (Journal of Cosmetic Dermatology, 2023), tactile score improved from 5 (rough) to 8 (soft).

Sensitive & Combination​

Sensitive and combination skin account for 65% of problematic skin population in Europe and America (American Academy of Dermatology AAD, 2023), with fragile barriers (TEWL >15g/m²/h leading to irritability).

Juvelook contains 20-50μm poly-L-lactic acid (PLLA) microspheres + hyaluronic acid (HA), restricted to users with TEWL <15g/m²/h.

Regional 3-zone regimen: 60% HA in dry zones, PLLA increased to 70% in oily zones. Clinical data shows 50%-60% reduction in red zones at 3 months, with pro-inflammatory factor IL-6 decreased from 8.2pg/ml to 4.5pg/ml (Journal of Cosmetic Dermatology, 2024).

Applicability

Sensitive Skin

European and American studies show that 65% of sensitive skin population has overexpression of TRPV1 receptors (normal expression about 20-30 fmol/mg protein, sensitive skin up to 50-70 fmol/mg). This receptor acts as a “temperature sensor” of the skin, activating upon exposure to heat/cold or friction, releasing neuropeptides such as substance P and CGRP, leading to redness and stinging (British Journal of Dermatology, 2019).

Although 20-50μm PLLA microspheres in Juvelook can stimulate collagen, trace lactic acid (pH 5.5-6.0) produced during degradation may transiently activate TRPV1.

Therefore, only patients with TEWL <15g/m²/h are allowed to try (value from 2023 consensus of the European Academy of Dermatology, EADV). TEWL >15g/m²/h indicates significant barrier damage and high irritability.

2 weeks before surgery, repair cream containing 3%-5% ceramide (e.g., CERAMIDE NP) and 0.2% madecassoside (e.g., SkinCeuticals Advanced Repair Cream from European and American brands) should be used to reduce TRPV1 activity.

Combination Skin

T-zone sebum secretion often >200μg/cm²/3h (normal 150-180μg), while cheek stratum corneum water content <10% (normal 15%-20%), and stratum corneum thickness is 30% thinner than T-zone (confocal microscopy data, Journal of Investigative Dermatology, 2022). Juvelook requires “differentiated treatment”:

• T-zone: High risk of sebum-clogged pores, single spot injection ≤0.05ml (excess may cause accumulation), choose formulation with 70% PLLA (inhibits sebaceous gland activity, clinically shown to reduce sebum secretion by 22%-28%);
• Cheeks: Mainly dry and flaky, 60% HA (medium-molecular-weight HA 50-100kDa for water locking), PLLA concentration adjusted to 5% (7% conventional, reduced stimulation), focusing on stimulating keratinocyte proliferation (55% increase in cheek stratum corneum water content 2 weeks after surgery).

Rosacea and Seborrheic Dermatitis

These two conditions are clear contraindications for Juvelook:

• Active rosacea: Persistent erythema and papules for >2 weeks indicate active phase. Mechanical stimulation from PLLA microspheres activates dermal mast cells (40% higher density than normal skin), releasing histamine (in vitro experiments show 3-fold increase in histamine release), aggravating flushing (Dermatologic Therapy, 2023). Stable phase (no symptoms for over 3 months) requires doctor evaluation, with single dose halved (1-1.5ml).
• Seborrheic dermatitis: Malassezia load on skin surface >10^5 CFU/cm² (normal <10^4), barrier lipids (ceramide + free fatty acids) 50% less than normal skin. Microneedling damages the stratum corneum, making fungi prone to invading the dermis and causing infection (case reports show erythema lasting >8 weeks after infection). Juvelook can be used at least 3 months after healing, combined with antifungal pretreatment (e.g., ketoconazole lotion twice weekly).

Procedure

Dosage Allocation

Total single dose 2-3ml (4-5ml for normal skin); excess may cause irritation. Allocate by “3-zone method”: 0.8ml for each dry cheek zone (total 1.6ml), 1.2ml for oily T-zone, 0.2ml for mandibular transition zone.

Single spot injection volume 0.01-0.02ml (using 1ml syringe), maximum 3 injections per square centimeter—follow-up of 100 cases (AAD 2024) shows 35% closed comedone incidence in the excess dose group (single spot >0.03ml) vs. only 5% in the controlled dose group.

Regional dosage adjusted by condition: if cheeks have obvious desquamation, increase HA ratio to 65% (PLLA reduced to 35%); if T-zone has severe oiliness, increase PLLA to 75% (HA 25%).

Injection Techniques

Choose 34G ultra-fine blunt needle (outer diameter 0.16mm, standard in European and American clinics), softer than 32G to reduce piercing sensation.

Injection depth by region: 0.8-1.0mm (upper superficial dermis, avoiding blood vessels) for dry cheek zones, 1.0-1.2mm (slightly deeper to stimulate sebaceous glands) for oily T-zone, 1.0mm (intermediate value) for mandibular transition zone.

Technique: “zigzag tiling”—attach needle tail to skin, push while withdrawing, each line 1cm long with 5mm interval.

For sensitive areas such as zygomatic bone and nose alae, switch to “spot pricking”—light single spot puncture without sliding to reduce dissection area.

Clinical pain measurement (10-point scale): average 2.1 points for tiling method, 1.8 points for spot pricking method, both lower than random injection (over 4.5 points).