Rejuran, HA Boosters, and Exosomes: What Differs

Rejuran-family injections (polynucleotide), HA microinjection, and exosomes differ in what gets placed in the dermis, how much clinical evidence backs each one, and how often retreatment is needed. HA microinjection has trial data measured out to six months from its FDA review, polynucleotide evidence rests mainly on small randomized trials, and no cosmetic exosome injectable currently holds regulatory approval anywhere. The starting point for choosing is whether your skin is dehydrated right now or its regenerative capacity has slowed, not which product name sounds most appealing.

Hello, I'm Dr. Kim Yeonjin, director of UH CELL Clinic's Gangnam branch. The question I hear most often in consultation is whether skin boosters are all basically the same treatment. I answer it with four concrete questions instead of an ingredient list: what is actually being injected, how far the evidence has been tested, how often you need to come back, and how many days of recovery it costs you.

Four Questions That Separate the Three Categories

The Evidence Isn't Weighted the Same Way

A systematic review published in the medical journal Cureus in 2026 pooled seven randomized trials of polynucleotide and polydeoxyribonucleotide injections, covering 183 patients in total. Wrinkle-related measures and patient satisfaction improved, and no serious treatment-related adverse events were reported. The authors were careful to note that sample sizes were small and protocols varied across studies, so larger trials are still needed before drawing firm conclusions. The mechanism behind that improvement is laid out in a narrative review in the Journal of Cutaneous and Aesthetic Surgery: this category stimulates dermal fibroblasts, producing a dose-dependent rise in collagen synthesis, which is the property that separates it from hyaluronic acid.

HA microinjection comes with more specific approval data. Allergan Aesthetics, an AbbVie company, released randomized controlled trial results when its HA microinjection product SKINVIVE by Juvederm received US FDA approval in 2023. The share of patients with at least a one-point improvement on the cheek smoothness scale was 58% at one month and 56% at six months, a finding also covered by Dermatology Times at the time of approval. What those numbers describe isn't instant radiance. It's a defined six-month checkpoint for re-evaluating the result.

Exosomes sit in a different regulatory position altogether. Reporting on exosomes in skincare by National Geographic in 2025 noted that the US FDA classifies human cell-derived exosomes as a biologic product, and no exosome product has been approved for cosmetic injection. A 2026 review in the Wiley journal Dermatological Reviews documented cases of delayed hypersensitivity reactions appearing weeks after intradermal injection, and pointed to a lack of long-term follow-up data and inconsistent regulation between countries as key limitations of the current evidence base.

How I Sort Patients Between the Options

If dryness and fine lines are the main concern and the travel schedule is tight, I look at HA microinjection first. Its evaluation checkpoints are defined, and the recovery is generally short.

If the skin has lost resilience from repeated laser sessions or frequent procedures, or the treatment area is thin, like under the eyes, I start with the polynucleotide category at a conservative dose. Building collagen response takes repetition rather than a single aggressive session, so I plan the interval around how the skin responds, not around a fixed calendar.

Either way, injection depth and the spacing between sessions do more to determine the outcome, and the likelihood of a side effect, than the category itself.

What I Check Before Recommending Either Option

• Current skin thickness and barrier condition in the treatment area
• Prior filler, laser, or booster history in the same zone
• Pain sensitivity and how much bruising risk is acceptable given your schedule
• Return travel date, since thin areas like the under-eye can bruise and need buffer days

At the Gangnam branch, this conversation happens with Japanese, Chinese, and English-speaking interpreting staff on site, so patients visiting from outside Korea can go through these details in their own language rather than through a translation app in the room.

Readers comparing these two categories in more depth may also find our related piece on HA boosters versus exosome treatments and what actually sets their downtime apart useful before a consultation.

FAQ

When do results actually become visible?

Hydration-related change tends to show up early, but the categories that rely on a collagen response need time to build. Even the HA microinjection approval studies measured improvement at two separate checkpoints, one month and six months. I'd rather re-evaluate at a set interval than judge the result from a single session.

How much downtime should I plan for?

Most patients see needle marks and mild redness that settle within a day. Thinner areas, like under the eyes, carry a higher chance of bruising that lasts longer, so if you have an important date coming up, I adjust the spacing of sessions around it.

Why don't you recommend exosome injections?

No cosmetic exosome injectable currently holds regulatory approval, and published cases of delayed hypersensitivity reactions after intradermal injection are accumulating in the medical literature. I prefer to build a treatment plan around categories where the approved use and the supporting evidence are both clear.

Can these categories be combined in one visit?

Because they target different depths and different goals, combining them is sometimes possible. I generally prefer to space out sessions rather than stack stimulation on the same day, and the right sequence depends on your treatment history.

Skin response and recovery time vary between individuals. Please discuss your specific condition and treatment plan with a licensed physician before proceeding.