How Long Do Rejuran and HA Skin Boosters Really Last?

Rejuran (a polynucleotide, or PN) and HA skin boosters such as Skinvive work through different mechanisms in the skin, and the duration numbers attached to each come from different kinds of research. Skinvive’s approved US trial reported six-month data under optimal treatment, while PN’s reported benefits mostly come from smaller, shorter studies without one standardized duration figure. Exosomes sit in a separate regulatory category altogether, so they need their own check before they belong in the same conversation.

Hello, I’m Dr. Kim Yeonjin, director of our Gangnam clinic. When a patient asks “what’s actually the difference between Rejuran and a skin booster,” naming the two ingredients doesn’t answer the question they’re really asking. The decision usually comes down to how long the result holds, when it becomes visible, and whether the swelling settles before a flight home. I don’t think that explanation is complete until I also say which kind of study each duration number comes from.

If you want the mechanical differences between the two ingredients first, our companion piece, Rejuran vs HA Skin Boosters: What Actually Differs, covers that ground. Here I want to focus on the evidence behind the duration claims and how recovery timing fits a short visit.

How Each Ingredient Behaves in the Skin

HA skin boosters rely on hyaluronic acid’s ability to hold water. A soft HA formulation is placed in tiny, closely spaced droplets into the dermis to raise the skin’s water retention, with the goal of smoother texture and more visible radiance. That is a different job from a filler, which is meant to change facial volume or contour. Skinvive, approved by the US FDA in 2023, belongs to this HA microdroplet category and is indicated for improving cheek smoothness in adults 21 and older.

Rejuran-line products (Rejuran Healer, Rejuran HB+, and similar) inject polynucleotides purified from salmon DNA into the dermis. Lampridou and colleagues, in a 2025 systematic review published in the Journal of Cosmetic Dermatology, describe PN as drawing interest in aesthetic medicine because of regenerative properties first used in wound healing. A 2026 review from DermatologyNews describes PN’s proposed action as stimulating fibroblast activity and dermal remodeling. Unlike HA, which fills and holds water directly, PN is aimed at the skin’s own repair process.

PN’s footprint in Korean clinical practice is large. Researchers led by Rho, in a 2024 survey published in the Journal of Cosmetic Dermatology, found that among 235 Korean dermatologists familiar with skin boosters, injectable PN was the preferred choice over fine-particle HA products. The same researchers also noted that clinical guidelines have not kept pace with how widely PN is already used.

Where the Duration Numbers Actually Come From

If a consultation gives you a number of months, it’s fair to ask which study that figure came from. Here is how I sort it.

Category	Example	Intended Effect	Duration Evidence	Nature of the Evidence
HA microdroplet	Skinvive	Hydration, smoother texture, radiance	6 months under optimal treatment	Randomized, multi-center, evaluator-blinded approval trial
PN	Rejuran Healer, Rejuran HB+	Regenerative signaling, skin quality	No standardized duration figure	Mostly small, short studies with inconsistent measurement methods
Exosomes	Topical, cosmetic-registered products	Varies by product	No approval basis as an injectable	Registered in Korea mainly as a cosmetic ingredient

Skinvive’s number is relatively specific. Allergan Aesthetics, reporting the trial data it released at the time of that 2023 FDA approval, found that the share of patients with at least a one-grade improvement on a cheek smoothness scale was 58% (73 of 125) at one month and 56% (69 of 124) at six months. Read the other way, that means close to half of patients had not gained a full grade of improvement by six months. I think mentioning that side of the number is part of giving an honest explanation.

One caution: “HA skin booster” describes a category of treatment, not a single product, and clinics use different HA formulations and additives. Skinvive’s six-month figure cannot be assumed to apply to every HA skin booster on the market.

PN needs its direction and its limits read together. The Lampridou review cited above found statistically significant improvement in wrinkles, texture, and elasticity across the studies it covered, with adverse events that were generally mild and transient. At the same time, it noted that the included studies were small and short, with inconsistent outcome measures, which limits how far the results can be generalized. That is why, when I explain Rejuran’s expected duration to a patient, I set the timing of the next session based on skin condition and how the skin responded after the first treatment rather than a fixed month count.

Exosomes Sit in a Different Regulatory Category

Exosomes come up often in conversations about glass skin, but their regulatory footing differs from HA and PN. During a 2022 National Assembly Health and Welfare Committee audit in South Korea, Rep. Choi Hye-young pointed out that injecting a substance into the skin is a medical act requiring a pharmaceutical-grade product, yet exosome products in circulation were registered with Korea’s Ministry of Food and Drug Safety as cosmetics rather than drugs, a category that does not carry the approval process or sterility standards required of pharmaceuticals.

Not much has changed since. The veterinary trade publication DailyVet reported in 2025 that no injectable exosome drug for human use has been approved, and that a Korean court had upheld a license suspension against a physician for injecting a cosmetic-registered exosome product.

If exosomes come up in a consultation, it is worth confirming two things: whether the product is approved as an injectable drug, and whether it is meant to be injected into the skin at all or applied topically. Without clear answers to both, placing exosomes in the same duration comparison as Rejuran or an HA booster does not really hold up.

Matching Recovery Time to a Short Trip

Both HA and PN are delivered as many small needle injections into the dermis, so injection marks, small bumps, swelling, and bruising can appear right after treatment. The most commonly reported reactions in the Skinvive trial were mild-to-moderate redness, lumps, swelling, bruising, pain, and tenderness. PN reactions were also described as generally mild and transient in the systematic review above.

“Transient” is the variable that matters most if you’re visiting for a short stay. How fast a reaction settles differs by person, and bruising in particular is hard to predict. For patients on a short trip, I usually recommend scheduling the injection early in the stay and leaving a buffer day before departure to check how the skin has responded.

Our Gangnam location operates as an on-site facility inside UH FLAT SIGNATURE Gangnam, a UHC group hotel (2nd and 3rd floors, WD Building, Teheran-ro 8-gil 13), and treatments are done in a private room. That means if some redness remains right after an injection, you can return to your hotel room without stepping outside. UHC hotel guests can choose one complimentary recovery option, either a 30-minute oxygen chamber session or a vitamin IV drip; using both brings the IV drip to 55,000 KRW. Full conditions are posted on our promotions page. Japanese, Chinese, and English-speaking staff are on site at the Gangnam location.

Five Answers Worth Getting in a Consultation

Whether a clinic explains itself well can be judged by whether you hear clear answers to these five questions:

1. The diagnosis. Did they examine your skin and explain whether your concern is primarily about hydration and texture, or about elasticity and regeneration?
2. The product’s identity. Did they name the actual ingredient family (HA, PN, or otherwise) and the specific product, not just a treatment nickname?
3. The basis for the duration number. Did they tell you whether that number comes from an approval trial or from a smaller study and clinical experience?
4. Approval status. If something is being injected, did they confirm it is approved as an injectable, and if it’s a topical product, did they say so plainly?
5. Recovery against your schedule. Did they map when swelling, bumps, and bruising typically settle against your stay and travel dates?

We diagnose skin condition first and design treatment around that result. At our Gangnam location, we offer Rejuran, Skinvive, and other skin booster options, and the diagnosis determines which ingredient family fits, or whether combining with an energy-based device makes more sense. I completed my graduate studies at Seoul National University and trained at Seoul National University Hospital. I serve as an Allergan faculty member (Juvéderm, Botox) and as a Potenza and Ultherapy Z Key Doctor, and I lecture for the Korean Society of Clinical Cosmetic Medicine and hold membership in the Korean Society for Aesthetic Plastic Surgery and Laser Medicine.

FAQ

Can Rejuran and an HA skin booster be done on the same day?

Combining PN and HA is an area of active study. A study published in the journal Skin Research and Technology examined intradermal injection of PN together with HA and its effect on facial redness. That said, combining the two isn’t necessary for everyone. We first confirm through diagnosis that both underlying concerns are actually present before deciding.

How is this different from a device treatment like Potenza?

An injectable skin booster places an ingredient directly into the dermis, while an energy-based device such as Potenza uses heat to work on skin texture and pores. Because the goals overlap in places, the choice often comes down to the underlying cause, either picking one approach or sequencing both.

Does one session guarantee glass skin for everyone?

That isn’t a promise I can make. Even Skinvive, which has approval-trial data behind it, showed a 56% rate of at least one-grade improvement at six months, meaning close to half of patients did not reach that mark. Skin thickness, the underlying cause of dryness, and daily environment all affect the outcome, so expectations are more realistic when they’re set after a diagnosis.

How many Rejuran sessions are needed?

PN does not have a standardized number of sessions or duration. The Korean dermatologist survey cited above also noted that guidelines lag behind how widely PN is used. I set the interval for the next session based on how the skin responds after the first treatment rather than a fixed count.

If you’d like to start with a diagnosis, tell us your travel dates and where you’re staying, and we’ll plan the treatment sequence and a recovery buffer around that schedule.

Individual responses to treatment and recovery time vary. Please consult a licensed physician for an accurate diagnosis and treatment plan.