Rejuran bumps: why they form and how long they last
The raised points that appear where Rejuran was injected are usually called papules or embossing. They are a physical elevation of fluid sitting in the dermis, not the nodule that matters with particulate products, and the literature reports them settling within a day or two. How many appear varies sharply by formulation — a 2025 split-face trial recorded 56.7% versus 13.3%.
The short answer
Bumps after Rejuran are an expected course, not a failure. Injected fluid rests briefly in the dermis and the elevation settles as it is absorbed. Two distinctions matter: time — settling within days is a papule, something newly palpable weeks later is a different problem; and material — Rejuran degrades, so the mechanism behind particulate nodules does not apply.
Why they form
Rejuran is placed into the dermis in small amounts at many points, roughly 3 to 5 mm apart. The fluid at each point does not disperse instantly, so each point becomes a small hill. What you see is the volume of the product, not a tissue reaction.
So size and number are set by volume per point, depth, spacing and formulation. The shallower the placement and the more per point, the more prominent. That is also why they show more in thin areas such as around the eyes.
How much the formulation actually decides
A 2025 split-face trial in 15 subjects addressed this directly: a conventional PN formulation on one side of the face and a formulation with adjusted pH and ionic strength on the other.
| Measure | Conventional | Ionization-adjusted |
|---|---|---|
| Embossing (papules) | 56.7% | 13.3% |
| Erythema | 60% | 40% |
| Injection pain (VAS 10) | 5.04 ± 2.19 | 3.39 ± 1.81 (p < 0.005) |
| Wrinkle improvement (CFGS, GAIS) | No significant difference between formulations | |
How to read it matters. The trial showed that changing formulation reduces bumps and pain — not that it works better. Wrinkle improvement was the same. With 15 subjects the percentages should not be generalised directly.
Practically it means this: how many bumps you get is substantially decided by which formulation is used, and that choice does not cost you the result.
What is normal, and until when
| Time | What you see | How to read it |
|---|---|---|
| Same day | Papules and redness | Your face now is not the result. Do not judge from photographs taken today |
| 1–2 days | Most papules absorbed | The literature reports elevation settling in a day or two |
| A few days | Bruising may remain | Occurs when a needle crosses a vessel. Highly variable by area and person |
| 2–3 weeks | Next session | Performed once the skin has recovered |
| Around session 2 | Texture starts to settle | Closer to “less rough” than to a dramatic change |
When to call — if elevation persists beyond a week; if something settles and then becomes newly palpable weeks later; if pain, heat or worsening redness accompanies it; or if the skin turns pale or mottled. The last is rare but should prompt immediate contact.
How this differs from a nodule
- A Rejuran papule — elevation made by the volume of fluid. Same day to two days. Gone once absorbed.
- A nodule from particulate products — tissue responding to particles that remain. In the literature the commonest time for delayed onset is three to four months after treatment. Rejuran degrades, so this mechanism does not apply.
Timing and management by family are set out in Nodules after treatment. Reversibility divides here too — PCL, PLLA and CaHA are not dissolved by hyaluronidase, while for Rejuran the concept does not apply because it degrades.
Reducing them
- Supported by evidence — formulation choice. The only item the 15-subject trial compared directly.
- Mechanistically reasonable — adjusting depth and volume per point. Shallower and larger is more prominent. We found no randomised human comparison of this.
- Convention — cooling immediately afterwards, avoiding sauna, alcohol and hard exercise that day. Widely advised, but we found no comparative data showing it lowers the rate.
- Scheduling — the most reliable regardless of evidence. Do not book within two or three days of something important.
Frequently asked
Are the bumps on the day a complication?
Usually not. They are physical elevation of fluid in the dermis and the literature reports them settling in a day or two. The mechanism differs from nodules with particulate products.
How many days until they go?
Typically one to two days in the literature. It can take a little longer depending on volume and area. If elevation persists beyond a week, contact the clinic.
Can I go to work the next day?
You can, but bumps and redness may show on the day and the next. Allow two to three days before anything important. The rate varies from 13.3% to 56.7% depending on formulation.
If I get a lot of bumps, was it done badly?
That is hard to conclude. Volume, depth, spacing and formulation all contribute, and the same injector gets different results by area. If it was not explained beforehand, though, that is fair to raise.
Can I use makeup to cover them?
We advise against it on the day, since tiny needle openings remain. From the next day it is usually fine, but this varies — follow the advice you were given.
Why do I bruise?
Because a needle crossed a small vessel. It is more common in vascular areas such as around the eyes. It is separate from the papules and usually lasts a few days.
Is something palpable weeks later still a papule?
Probably not. Rejuran papules settle within a day or two. If something settles and then becomes newly palpable weeks later, another cause should be looked at — please contact the clinic.
Does a formulation with fewer bumps also do less?
Not in that trial. In the 15-subject split-face comparison, wrinkle improvement (CFGS, GAIS) did not differ significantly; only pain and embossing did. The sample was small.
Read next
Who wrote this
Lee Chi-Hak, Director, Miso Clinic Daegu
4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, Korea (Exit 1, Kyungpook National University Hospital Station)
+82-53-428-2700 · www.clinicmiso.co.kr
References
- Jeon W, Park M, Kim SW, Kim J. Efficacy of Ionization-Adjusted PN Filler in Minimizing Injection Pain: A Randomized, Patient-Blinded, Split-Face Study. Aesthetic Plast Surg. 2025;50(7):2723-2730. PMID 41361144
- Hong JY, et al. Therapeutic Performance of Needle Injection Versus Needle-Free Jet Injector System for Polynucleotide Filler. J Cosmet Dermatol. 2025;24(1):e16595. PMID 39370844
- Lee YJ, et al. J Dermatolog Treat. 2022;33(1):254-260. PMID 32248707 (27 subjects; no serious adverse events)
- Rho NK, et al. Clin Cosmet Investig Dermatol. 2026;19:557226. PMID 41939258
- Lampridou S, et al. J Cosmet Dermatol. 2025;24(2):e16721. PMID 39645667
What we could not verify
- A randomised human comparison of depth and volume per point against papule rate.
- Comparative data showing that cooling or aftercare lowers the rate.
- Papule rates split by area (periocular versus full face).
- Korean adverse-event tallies for Rejuran treatment.
This is general medical information and does not replace consultation. Responses after treatment depend on individual skin and injection design; if a change concerns you, contact the clinic that treated you. Prices and promotions are not covered.
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