Skin Boosters at Le.J: What Juvelook and Rejuran Do

Skin Booster Treatments (Juvelook & Rejuran): What Injectable Skin Boosters Actually Do

Medically reviewed by Dr. Kim Ji Sun, M.D., Ph.D., Board-Certified Otolaryngologist

A skin booster is an injectable treatment that delivers skin-focused active ingredients into the skin to improve its overall quality. It is not a volumizing product, and treating it as one is the most common misunderstanding people bring to the appointment. Le.J Plastic Surgery in Seoul offers Juvelook and Rejuran as its skin booster treatments, and naming the actual products matters, because the two work by different mechanisms.

Skin quality is a different target from volume

Fillers answer a shape problem. Skin boosters answer a surface problem: hydration, elasticity, texture, fine lines, and general dullness.

Le.J Plastic Surgery describes its skin booster approach as the deep delivery of beneficial active ingredients into the skin, and positions the treatment for adults who want to improve hydration, elasticity, texture, fine lines, or overall skin quality without surgery. The clinic lists the reasons US patients ask about it in similar terms: dehydration, dullness, fine lines, reduced elasticity, and uneven texture.

The distinction has a practical consequence. If what bothers you is a fold that has deepened or a contour that has flattened, a skin booster is the wrong tool, and Le.J Plastic Surgery offers structural treatments separately within the same Quick-Petit category. If what bothers you is how the skin itself looks in daylight, this is the right category.

The underlying change is ordinary. The American Society of Plastic Surgeons notes that facial skin stretches with age and that sun exposure, heredity, and lifestyle all affect it, alongside the loss of fat beneath the surface. Skin boosters do not reverse that; they aim at the quality of the tissue that remains.

A note of skepticism belongs here too, and it comes from a public source rather than from us. MedlinePlus, the patient-education service of the US National Library of Medicine, observes on its skin aging page, which draws on the National Institute on Aging, that many products claim to revitalize aging skin or reduce wrinkles while only a few have been approved by the Food and Drug Administration for sun-damaged or aging skin. The same page notes that aging skin tends toward dryness and can take longer to heal. Both points are worth carrying into a consultation about any injectable marketed on skin quality.

What Juvelook is

Le.J Plastic Surgery states that Juvelook combines hyaluronic acid with poly-D,L-lactic acid, usually written PDLLA.

The hyaluronic acid component is well characterized. The StatPearls entry on the National Library of Medicine's Bookshelf describes hyaluronic acid as a high-molecular-weight polysaccharide distributed widely through the connective-tissue extracellular matrix, and records that hyaluronic acid preparations are available in injectable, topical, ocular, and joint formulations. In cosmetic use it notes low allergic response, ease of injection, rapid recovery, reproducibility, and immediate results among the reasons the material became popular.

The polylactic acid component belongs to a family of collagen-stimulating materials. StatPearls describes the mechanism in its review of poly-L-lactic acid, a related compound: after injection there is a temporary immediate swelling from tissue fluid and the carrier, which settles within two to three days; then, as the carrier is absorbed, the particles provoke a macrophage-mediated response, are broken down to lactic acid monomers, and stimulate the production of new type-I collagen fibers. Roughly half the material is digested within six months, and the duration of action is reported as twelve to twenty-four months.

That review describes poly-L-lactic acid specifically, not the poly-D,L form used in Juvelook, so it explains the family mechanism rather than this product's own figures. What it does establish is why a collagen-stimulating injectable behaves differently from one that simply occupies space: the visible change arrives late and builds.

What Rejuran is

Le.J Plastic Surgery describes Rejuran as a polynucleotide-based injectable treatment, and separates it from hyaluronic acid products in its own comparison: a hyaluronic acid skin booster focuses primarily on hydration and skin quality, while Rejuran is used with skin-rejuvenation and tissue-remodeling goals in view.

The clinic offers the two together as its skin booster treatment, describing the pairing as intended to revitalize the skin. Which of them leads in your plan, and in what proportion, is a clinical decision taken at consultation against your skin condition and what you want changed.

What the session involves

The treatment is straightforward in outline. The area is cleansed and prepared, the treatment areas are marked or identified, and the chosen product is delivered through multiple superficial injections. Basic skin care and post-treatment instructions follow.

Le.J Plastic Surgery asks that you arrive with clean skin and tell the medical team about allergies, medications, medical conditions, previous injectable treatments, and any active skin problems. Treatment over an active infection or significant inflammation is avoided.

Consultation focuses on your skin condition, your goals, and which skin booster option fits, after which the product and approach are tailored to your individual concerns.

Why one appointment is usually not the plan

This is the expectation most worth adjusting in advance.

Le.J Plastic Surgery states that a skin booster treatment plan can involve multiple sessions rather than a single treatment, that published hyaluronic acid skin booster protocols commonly use a series of treatments followed by maintenance sessions, and that the exact number and spacing depend on the product selected and on the individual plan.

On results, the clinic reports that initial improvements can develop after treatment with further improvement possible following a series, that hyaluronic acid skin booster research has demonstrated measurable changes in hydration and elasticity after treatment, and that repeated treatments can produce more progressive improvement in skin texture. Maintenance treatment may be used to preserve what has been achieved.

For anyone traveling, that shapes the trip. A single visit can start a course; it does not usually complete one. The honest question to put to the clinic before booking flights is what a realistic first stage looks like within the time you actually have.

Where these products sit in the wider regulatory picture

Skin boosters are injected products, and the general cautions that apply to injectables apply here.

The US Food and Drug Administration classifies dermal fillers as medical device implants, restricts their approval to adults aged 22 and over, and publishes a list of injection sites and purposes it advises against — among them several facial regions and any use intended to enlarge the breasts, buttocks, or feet. It warns separately that no needle-free device is approved for delivering a filler, and that injectable silicone holds no aesthetic approval at all.

Products marketed as skin boosters are regulated differently in different countries, and a product available in Korea may not hold the same approval in the United States. That is a reason to ask the clinic directly what it is using and why, not a reason to assume anything about safety in either direction.

Risks and recovery

Le.J Plastic Surgery describes limited downtime for most people, with mild redness, swelling, tenderness, bruising, or small injection-site bumps that generally settle as the skin recovers. Recovery varies with the product, the injection technique, and individual response.

The clinic lists redness, swelling, tenderness, bruising, and temporary injection-site changes as common short-term effects. More significant complications are uncommon but can occur with injectable facial treatments, including infection, inflammatory reactions, nodules, and vascular complications.

Afterward you are asked to follow the individual instructions you are given, avoid unnecessary irritation of the treated skin while temporary redness or swelling settles, and keep to gentle skin care and sun protection during the early period.

Who should postpone

Le.J Plastic Surgery states that anyone with an active infection or significant inflammation at the intended injection area should postpone treatment, and that suitability may also be affected by allergies, medical conditions, medications, pregnancy, or other individual factors requiring medical assessment before an injectable treatment.

Fitting skin boosters into a wider plan

Le.J Plastic Surgery describes skin booster treatment as something that can be incorporated into broader plans addressing skin quality, facial rejuvenation, and lifting, and offers it alongside its other aesthetic treatments.

The sensible sequence is usually to decide what the main complaint is first. Skin quality and facial structure are separate conversations, and a plan that tries to answer both at once without deciding which leads tends to disappoint on both counts.

If you want that assessment before traveling, Le.J Plastic Surgery provides consultation and reservation through its own system; requests can be made on the clinic's consultation page. How the practice describes its treatment philosophy is set out on its about page.

The Bottom Line

• Skin boosters target skin quality — hydration, elasticity, texture, fine lines — rather than facial volume or contour.
• Le.J Plastic Surgery uses two named products: Juvelook, combining hyaluronic acid with poly-D,L-lactic acid, and Rejuran, a polynucleotide-based injectable.
• A plan typically involves a series of treatments followed by maintenance, not a single appointment.
• Downtime is limited for most people, with temporary redness, swelling, tenderness, bruising, or small injection-site bumps.
• Anyone with active infection or inflammation at the injection site should postpone, and pregnancy, allergies, and medications all affect suitability.

Frequently Asked Questions

How is a skin booster different from a filler?

A filler is placed to restore volume or contour. A skin booster delivers skin-focused active ingredients into the skin to improve its quality — hydration, elasticity, texture, and fine lines. Le.J Plastic Surgery describes its skin booster approach as the deep delivery of beneficial active ingredients, and offers structural treatments separately.

What is actually in Juvelook?

Le.J Plastic Surgery states that Juvelook combines hyaluronic acid with poly-D,L-lactic acid. StatPearls describes hyaluronic acid as a polysaccharide found throughout the connective-tissue extracellular matrix, valued in cosmetic use for its low allergic response and immediate effect, while polylactic acid materials work by stimulating the skin to produce new collagen over time.

What is Rejuran made from?

Le.J Plastic Surgery describes Rejuran as a polynucleotide-based injectable treatment, and distinguishes it from hyaluronic acid boosters by noting that polynucleotide treatment is used with skin-rejuvenation and tissue-remodeling goals rather than hydration alone.

How many sessions will I need?

Le.J Plastic Surgery states that a treatment plan can involve multiple sessions rather than a single treatment, and that published hyaluronic acid skin booster protocols commonly use a series followed by maintenance sessions. The number and spacing depend on the product selected and on your individual plan, so this is a question to settle at consultation.

When will I see a difference?

The clinic describes initial skin-quality improvements developing after treatment, with further improvement possible after a series. It reports that hyaluronic acid skin booster research has shown measurable changes in hydration and elasticity, and that repeated treatments can give more progressive improvement in texture.

Is there downtime?

Most people have limited downtime. Le.J Plastic Surgery describes mild redness, swelling, tenderness, bruising, or small injection-site bumps that generally settle as the skin recovers, with recovery varying by product, technique, and individual response.

How should I look after my skin afterward?

Follow the individual instructions you are given, avoid unnecessary irritation of the treated skin while any temporary redness or swelling settles, and keep to gentle skin care with protection from excessive sun exposure during the early recovery period.

Can skin boosters be combined with other treatments?

Yes. Le.J Plastic Surgery describes skin booster treatment as something that can be incorporated into broader plans addressing skin quality, facial rejuvenation, and lifting, offered alongside its other aesthetic treatments, with sequencing decided clinically.

This article is for general informational purposes and does not constitute individualized medical advice. It is not a self-diagnosis tool. Treatment candidacy, technique, and expected outcomes can only be determined through a consultation with a qualified surgeon.

References

• StatPearls: Hyaluronic Acid
• StatPearls: Poly-L-Lactic Acid
• FDA: Dermal Fillers (Soft Tissue Fillers)
• ASPS: Dermal Fillers
• MedlinePlus: Skin Aging