Korean Skin Boosters (2026): Polynucleotide vs PDLLA, Compared Honestly

Aug 29

5 min read

Skin boosters are injectable treatments that deliver bioactive material into the dermis to improve skin quality rather than to add volume or restrict muscle movement. In Korean clinics the category is dominated by two distinct chemistries: polynucleotide-based products, of which Rejuran is the best known, and poly-D,L-lactic acid microsphere products such as Juvelook. They are routinely presented as interchangeable in clinic menus. They are not. This guide separates the two by mechanism, sets out what the published evidence does and does not currently support, and lists the questions worth asking before booking.

Polynucleotide Boosters: What Rejuran Contains

Polynucleotide products contain purified DNA fragments, most commonly derived from salmon or trout milt, processed to remove protein and reduce immunogenic potential. Once injected into the dermis, the proposed mechanism is that these fragments act as a scaffold and as a source of nucleotides, and that they modulate fibroblast activity and inflammatory signalling. Proponents describe an effect on skin hydration, elasticity and fine texture rather than on volume.

Clinically the treatment is usually delivered as a series of sessions spaced several weeks apart, with maintenance thereafter. Because the material is injected as multiple small dermal deposits, transient papules, swelling and bruising for several days are common and expected rather than a complication.

PDLLA Microsphere Boosters: What Juvelook Contains

Poly-D,L-lactic acid products contain biodegradable polymer microspheres suspended in a carrier. The stated mechanism is different in kind: rather than supplying nucleotides, the microspheres are intended to provoke a controlled foreign-body response that stimulates gradual collagen deposition around each particle as the polymer degrades. This is the same broad principle behind established collagen-stimulating injectables, adapted to a finer particle size intended for more superficial placement.

Two practical consequences follow. First, results build slowly, typically over months rather than weeks, because collagen synthesis is the endpoint. Second, nodule formation is the characteristic risk of the collagen-stimulator class, and depends heavily on injection depth, dilution, reconstitution time and post-treatment massage. Technique matters more here than with most injectables.

The Comparison Nobody Makes Clearly

Because both are marketed under the umbrella term skin booster, patients frequently assume they are competing versions of the same thing. Mechanistically they occupy different roles. Polynucleotide products are generally positioned for skin quality, hydration and barrier-related concerns, with a shorter onset and shorter duration. PDLLA products are positioned for gradual structural collagen support, with slower onset and longer persistence.

A reasonable way to frame the choice is by what is actually deficient. If the complaint is dullness, roughness, fine crepiness and dehydration in reasonably firm skin, the polynucleotide route is the more direct match. If the complaint is progressive laxity and thinning where collagen support has genuinely diminished, a collagen-stimulating product addresses the underlying deficit more plausibly. Skin thickness is a useful predictor in both cases, as discussed in our guide to skin thickness as a decision variable.

What the Evidence Currently Supports, and Where It Is Thin

Both categories have published studies reporting improvements in measured skin parameters such as elasticity and hydration, and both have supportive case series. The limitations are consistent and should be stated plainly. Sample sizes in much of the literature are small. Follow-up periods are often short relative to the claimed duration of effect. Many studies are conducted or funded by product manufacturers. Head-to-head randomised comparisons between polynucleotide and PDLLA products are scarce.

This does not mean the treatments do not work. It means the confidence interval around any specific promised outcome is wider than clinic marketing implies. Treat quantified claims about percentage improvement with scepticism unless the source study is identified, and ask which study a clinic is citing.

Safety, Contraindications and Realistic Downtime

Common short-term effects for both categories include injection-site swelling, bruising, tenderness and visible papules for several days. Less common but more consequential risks include infection, granuloma or nodule formation — a particular consideration for the collagen-stimulator class — and, rarely, vascular events if product is injected into or compresses a vessel.

Treatment is generally avoided in active skin infection at the site, during pregnancy and breastfeeding given absent safety data, in patients with known hypersensitivity to a component, and in those with autoimmune or granulomatous conditions without specialist input. Fish-derived polynucleotide products warrant explicit discussion for anyone with a fish allergy, even though the purification process is designed to remove protein. Plan for several days of visible papules or swelling before any event that matters to you.

Verifying the Product You Are Actually Receiving

Counterfeit and unapproved injectables circulate in the medical tourism market. Reasonable verification steps include asking to see the sealed product packaging before it is opened, confirming the manufacturer and lot number, asking whether the specific product holds Korean Ministry of Food and Drug Safety approval for the indication being treated, and confirming that a licensed physician performs the injection. Legitimate clinics accept these questions without difficulty; reluctance is itself informative.

Frequently Asked Questions

How many sessions are typically needed?

Protocols commonly involve a course of three to four sessions spaced two to four weeks apart, followed by periodic maintenance. Exact numbers vary by product, concentration and individual response, and a clinic should give you a written plan rather than an open-ended series.

How long do results last?

Reported durability differs by chemistry, with polynucleotide effects generally described as shorter-lived and collagen-stimulator effects as longer. Published follow-up is limited, so any single figure you see quoted should be treated as an estimate rather than a specification.

Can these be combined with lasers or toxin?

Combination protocols are used in practice, but sequencing and interval matter, particularly where a laser causes inflammation that could interact with an injected material. Ask specifically about intervals rather than assuming same-day stacking is safe.

Are they suitable for melasma or acne scarring?

Neither is a first-line treatment for either condition. They may be used adjunctively for overall skin quality, but pigmentary and scarring concerns have their own established treatment pathways that should be addressed on their own terms.

Is there a minimum age or a point where they are not worthwhile?

There is no meaningful age threshold, but there is a suitability threshold. Where laxity is advanced enough that a surgical or energy-based lift is the appropriate intervention, injectable boosters will produce a disappointing result relative to expectation and cost.

How to Approach a Consultation

Ask the clinic to name the exact product, state its mechanism, explain why that mechanism matches your specific concern, and outline the expected onset, duration and maintenance interval. If the answer treats all skin boosters as one undifferentiated category, you are receiving a menu item rather than a clinical recommendation.

Sources and Further Reading

Background and verification: Korea Health Industry Development Institute (KHIDI) | Korean Medical Association (KMA) | PubMed: polynucleotide and PDLLA skin booster studies

This article is general information, not medical advice, and is not affiliated with or endorsed by any manufacturer. Product suitability, risks and outcomes vary by individual and require assessment by a licensed physician.