Choose the Rejuran conversation
If thin, crepey skin and fine lines are your main concern, Rejuran is the focused option to ask about. It is used around the eyes with the aim of improving skin quality rather than creating deliberate volume.
Doctor-led under-eye comparison
Rejuran vs Biostimulator
Rejuran is the skin-first choice. The hydrating biostimulator is the skin-plus-support choice. If your under-eyes look crepey, finely lined or mildly hollow, this guide will help you understand which conversation to have first.
The short answer
Two strong options.
One precise decision.
Start with what you want to change. The better fit is the one whose treatment goal matches your anatomy—not the product with the loudest promise.
Choose the hydrating biostimulator conversation
If fine lines sit alongside a shallow under-eye hollow, the hydrating biostimulator brings a different proposition: a hybrid collagen-stimulating injectable designed to support skin depressions and soft-tissue volume.
Rejuran vs hydrating biostimulator
Skin refinement or
refinement with support?
This is the decision that matters. No direct under-eye trial has compared Rejuran with the hydrating biostimulator, so a responsible recommendation must combine the available research with a close examination of your skin and contour.
Consideration
01 · Skin quality
Rejuran
Polynucleotide device02 · Skin + support
Hydrating biostimulator
PDLLA and hyaluronic acid deviceIts strongest pitch
Focused skin refinement. Rejuran is the cleaner conversation when fine texture, crepiness and delicate-looking skin are the priority.
Refinement with support. The hydrating biostimulator is the more structural conversation when skin quality and a shallow depression need to be considered together.
What it is
A Class III medical device containing animal-derived sodium polynucleotide gel. Its Australian intended purpose includes tissue restoration and reconstruction, particularly around the eyes and mouth.
A Class III medical device containing poly-D,L-lactic acid and hyaluronic acid. Its Australian intended purpose includes filling skin depressions and restoring or enhancing soft-tissue volume.
Best-fit discussion
Fine lines, thin-looking skin, crepey texture and an under-eye that needs quality more than volume.
Fine lines or skin-quality concerns accompanied by a mild hollow where controlled support may also be useful.
What it will not fix
Rejuran does not remove eye bags, replace meaningful volume loss or directly clear brown pigment or visible vessels.
The hydrating biostimulator does not remove eye bags, directly clear pigment or vessels, or correct significant eyelid laxity. Fluid-prone under-eyes require particular caution.
Under-eye evidence
Periocular polynucleotide evidence includes a 27-person randomised split-face trial. A wider nine-study review covered 219 patients, although study quality was low to moderate.
Hydrating biostimulator-specific evidence includes a 15-person prospective under-eye cohort with no control group. The results are encouraging, but the study is too small to establish superiority.
Recovery and risk
Temporary raised bumps, swelling, redness, tenderness and bruising can occur. The material is animal-derived and may not suit every patient.
Swelling, bruising and tenderness can occur. Delayed nodules or inflammatory reactions are recognised polymer-related complications and can be difficult to manage.
Bottom line
Ask about Rejuran when you want a skin-first plan with no intention to deliberately add structure.
Ask about the hydrating biostimulator when the plan may need skin refinement plus carefully judged support.
Why the exact product matters
“Biostimulator” is a broad category, not a single treatment. This comparison is specifically between Rejuran and the hydrating biostimulator because their materials, Australian intended purposes, evidence and complication profiles are different. Evidence for another product cannot simply be transferred to either one.
The deciding factor
Your anatomy chooses
the better starting point.
Thin skin sits over muscle, ligaments, fat and bone. A fine line is a surface concern; a tear trough is a contour concern. If both are present, the treatment discussion changes.
Read the anatomy review ↗Skin qualityFine lines, texture and translucency point towards a skin-first Rejuran discussion.
ContourA shallow depression may bring the hydrating biostimulator’s support role into the conversation.
PuffinessProminent bags or fluid can make either injectable the wrong first move.
The research in plain English
Encouraging evidence.
No manufactured winner.
Both options have a credible reason to be considered, but their under-eye studies are small and answer different questions. The research supports a tailored choice—not a blanket claim that one product is better.
27people
Randomised split-face trial
Periocular polynucleotide compared with non-cross-linked hyaluronic acid
Participants received one treatment on each side of the eye area. Overall appearance ratings were similar, while some skin measurements favoured polynucleotide. The study supports the skin-quality rationale but does not prove Rejuran is superior to the hydrating biostimulator.
Read the study ↗Rejuran takeawayPromising skin dataSmall study
219patients
2025 systematic review · nine studies
The wider polynucleotide evidence
The review found possible improvements in wrinkles, texture and elasticity. It also found low-to-moderate study quality and varied treatment methods, so expectations still need to be individual.
Read the systematic review ↗Rejuran takeawayEvidence is growingBetter trials are needed
15patients
2026 prospective under-eye cohort
Hydrating biostimulator-specific early evidence
Fifteen women received three sessions. Investigator and patient scores improved and no adverse events were reported. There was no control group, the sample was small, and the manufacturer supported participant travel.
Read the cohort ↗Hydrating biostimulator takeawayEncouraging early signalNot a head-to-head trial
The practical message
If the problem is mainly skin, lead with Rejuran. If fine skin sits over a shallow hollow, put the hydrating biostimulator on the shortlist. If puffiness or another cause dominates, do not force either product into the plan.
Make the choice clearer
Which conversation
sounds more like you?
You do not need to diagnose yourself. Use these two starting points, then let an in-person assessment test the assumption.
“My skin looks thin and crepey.”
You notice fine lines and delicate texture, but little true hollowing. You want refinement without deliberately adding support or volume.
Start with the skin-first option“I see fine lines and a shallow hollow.”
Your concern looks partly textural and partly structural. You want to discuss a gradual collagen response with carefully controlled support.
Start with the skin-plus-support optionDo not buy the wrong solution for the right concern
If eye bags, fluid, brown pigment, visible vessels or significant laxity create most of the tired appearance, neither Rejuran nor the hydrating biostimulator is an automatic answer. A precise assessment can save you from paying for a treatment that does not match the cause.
Discuss your under-eyes · 1300 338 307A confident decision is an informed one
Know the upside.
Know the trade-offs.
Rejuran: the trade-off
Rejuran keeps the goal focused on skin quality, but it may require a course of treatments and maintenance. Temporary visible bumps, redness, swelling, tenderness and bruising can occur after injection.
Hydrating biostimulator: the trade-off
The hydrating biostimulator may address skin quality and a shallow depression in one strategy, but precise placement matters. Delayed nodules or inflammatory reactions can appear months later and may require prolonged treatment.
Read the nodule-management review ↗Risks shared by injections
Possible risks include infection, asymmetry, persistent swelling, inflammation or lumps. Injection near the eyes can cause blocked blood flow, skin injury or eye injury. Alternatives include no treatment or another clinical pathway.
Common patient questions
What to know
before you book.
Is the hydrating biostimulator better than Rejuran for under eyes?+
Not for everyone. Rejuran has the clearer skin-first role. The hydrating biostimulator has the stronger skin-plus-support proposition when a shallow depression is also part of the concern. Your anatomy decides which advantage is relevant.
Can Rejuran and the hydrating biostimulator be compared directly?+
Only with caution. There is no direct under-eye trial comparing them. Existing studies involve different patients, outcomes and methods, so one study cannot be used to crown a universal winner.
Which option is better for crepey under-eye skin?+
Rejuran is the more focused discussion when fine texture and crepiness are the main concerns without meaningful hollowing. The hydrating biostimulator may enter the discussion when the skin concern sits alongside a shallow depression.
Which option is better for a tear trough?+
The hydrating biostimulator is designed to support skin depressions and soft-tissue volume, so it may be considered for selected shallow hollows. Neither product is automatically appropriate for a deep trough, prominent eye bags or fluid-prone tissue.
Can either product remove dark circles?+
Only if the treated feature contributes to the darkness. Neither product directly clears every brown pigment pattern or visible vessel, and neither removes an eye bag. The cause must be identified first.
What happens during an under-eye consultation?+
Your clinician will ask what concerns you, examine the skin and lower-eyelid contour, and review relevant health history. Suitable options, no-treatment alternatives, recovery, maintenance, costs and risks should be explained before you decide. You can contact MA360 to arrange an assessment in Chatswood or Hurstville.