Skin Booster Side Effects: Bumps, Bruising and Downtime by Type
Medical Director Dr Sin Yong explains the side effects of each skin booster family, how long bumps and bruises usually last, and which signs need a call.
WhatsApp to Enquire →Key facts ↓Skin booster side effects are usually small raised bumps at the injection points, redness and the occasional pinpoint bruise. With hyaluronic acid boosters and Rejuran, bumps typically flatten within hours to three days; Profhilo leaves a few larger bumps for a day or two; PDLLA boosters such as Juvelook can bruise along the cannula track. A lump lasting beyond a week needs a review.
- Mild and brief: a 2026 systematic review of Profhilo (nine studies, 278 participants) found adverse events were "mild, expected, and usually resolved within 72 hours" [1].
- How often: in a 16-week study of 64 women, minor temporary local skin reactions occurred in about a quarter of participants, with tolerability rated good or excellent [2].
- PDLLA: in a 24-month safety study of poly-DL-lactic acid filler, 4 injection-site events were reported among 58 people, all mild and resolved by the two-month visit [7].
- Polynucleotides: a 2024 review found polynucleotide studies reported "varying degrees of efficacy and safety", and advised clinicians to be aware of current limitations and risks [4].
- Near the eyes: a 2024 report described poly-D,L-lactic acid flowing back along the injection track over the lower eyelids [8], and a case report described firm nodules three weeks after PDLLA in the tear trough [9].
What are the common side effects of skin boosters?
The common side effects of skin boosters are small raised bumps at the injection points, redness, tenderness and the occasional pinpoint bruise, usually settling within hours to a few days.
Most injected boosters are placed as many small deposits in the skin, so a grid of small bumps is expected straight afterwards: the bump is the product sitting in the layer it is meant to act in. It flattens as the product spreads and is absorbed. In a systematic review of one hyaluronic acid booster, adverse events such as bruising, swelling, a light pinching sensation and a small bump were mild and usually resolved within 72 hours [1].
Booster families differ, though, and so do their side effects [6]. Hyaluronic acid boosters, polynucleotides such as Rejuran, hybrid hyaluronic acid such as Profhilo, and poly-D,L-lactic acid (PDLLA) such as Juvelook each behave a little differently. How each one works is on skin boosters in Singapore. For fillers and collagen stimulators, see the filler complications overview.
How long do skin booster bumps last?
Bumps usually last from a few hours to three days, depending on the booster: polynucleotides and fine hyaluronic acid droplets settle fastest, Profhilo’s larger bumps within a day or two.
| Booster | How it is placed | Typical bumps | Bruising | Usual social downtime | Contact the clinic if |
|---|---|---|---|---|---|
| Hyaluronic acid microdroplets (for example Skinvive) | Many small droplets in the skin | Small bumps, usually settling within a day or two | Pinpoint, occasional | A day or two | Bumps beyond a week |
| Profhilo | Five points per side of the face | A few larger bumps, settling within a day or two | Occasional, at a point | One to two days | A firm lump beyond a week |
| Profhilo Structura | Blunt cannula into the fat of the lateral face, from a few entry points | No grid of bumps; mild swelling at the sides of the face, settling within a few days | Occasional, at entry points | Most return to normal activities the same day | Asymmetry or a lump that persists |
| Rejuran (Healer, HB, S) | Small deposits across the area | Small bumps at each point, usually flat within hours to a day | Small bleeding points; occasional bruise | About a day | Bumps beyond a week |
| Rejuran Eye | Thinner formulation, small deposits around the eye | Small bumps, thinner product lowers the chance of visible ones | Bruising more likely around the eye | A day or two | Any change in vision: emergency |
| PDLLA (Juvelook) | Small injections or a fine cannula | Grid of bumps, flat within hours to a day or two; fewer with cannula | Can bruise along the cannula track | Allow at least a week before an event | Firm nodules weeks later |
| Needle-free Deep Synergy Booster | Applied to the skin, carried in by ultrasound delivery | No needle bumps | No needle bruising | Usually none to minimal | Irritation that persists |
Bruises take longer than bumps, often up to a week, and on light-brown and darker skin a bruise or an inflamed bump can occasionally leave a brown mark that fades over weeks, so sun protection matters in Singapore. If you have an event, leave a few clear days, and a week for PDLLA. The step-by-step treatment day is on the skin booster page.
What are Rejuran side effects?
Rejuran side effects are mainly small bumps and redness at each injection point, which usually flatten within hours to a day, plus occasional bruising; serious reactions are rare.
Rejuran is a polynucleotide (PN) booster, placed as small deposits in the upper dermis. The bumps are expected: they are the gel where it should be, and they flatten as it spreads. Too deep, and the product passes below the layer it is meant to support; too heavy in one spot, and bumps last longer. In a small series of five patients treated with a long-chain polynucleotide, no serious side effects were reported [3], and an expert consensus has set out technique, volumes and intervals for these products [5].
- Expected: bumps for hours to a day, redness, small bleeding points, mild tenderness.
- Less common: a bruise lasting up to a week; an acne or cold sore flare in the treated area.
- Needs review: bumps or lumps lasting more than a week.
- Emergency: swelling of the lips, eyes or throat, or difficulty breathing.
Because Rejuran is not a heat or light treatment, it carries little risk of pigment change in darker skin, although bumps and bruising can occur in anyone. Note that polynucleotides are not dissolved by hyaluronidase. More detail is on Rejuran in Singapore and, day by day, in Rejuran downtime.
What are Profhilo side effects?
Profhilo side effects are a few larger bumps at the injection points, mild swelling, tenderness and occasional bruising, which usually settle within one to three days.
Profhilo is a hybrid of high- and low-molecular-weight hyaluronic acid placed at five points on each side of the face, so instead of a grid of small bumps there are a few larger ones that spread over a day or two. In a 16-week study of 64 women, minor temporary local reactions occurred in about a quarter, and tolerability was rated good or excellent [2]; a 2026 review of nine studies found adverse events were mild and usually resolved within 72 hours [1].
Because Profhilo is hyaluronic acid, a lump that persisted unusually could be dissolved with hyaluronidase [10], although this is rarely needed. More is on Profhilo and, for the deeper lateral-cheek version, Profhilo Structura.
What are Juvelook and PDLLA side effects?
Juvelook and other PDLLA boosters cause bumps for hours to a day or two, redness and bruising, and less often firm papules or nodules, especially with superficial or concentrated placement.
Poly-D,L-lactic acid is a collagen-stimulating booster, so it behaves partly like a booster and partly like a collagen stimulator. In a 24-month safety study, 4 injection-site events were reported among 58 people, all mild and resolved by two months [7]. Near the eyes more caution applies: one report described the product flowing back along the injection track over the lower eyelids [8], and a case report described firm, non-inflamed nodules three weeks after treatment of the tear trough [9].
PDLLA cannot be dissolved with hyaluronidase, so prevention is the main tool: even spread, small amounts and the right depth. A nodule that does form is examined and treated in its own right. More is on Juvelook in Singapore, and stimulator nodules are compared in collagen stimulator side effects.
“After a skin booster, the bumps are the product sitting exactly where it should. The bump that worries me is the one still there a week later, or the one that was never there on the day.”
When is a bump after a skin booster not normal?
A bump is not normal if it lasts beyond a week, is red, hot or increasingly tender, appears weeks later, or comes with pale skin or any vision change.
- Still there after a week. Usually product too heavy in one spot or too superficial. Hyaluronic acid can be dissolved if needed; other boosters are examined first.
- Hot, red, increasingly tender. Possible infection; contact the clinic the same day.
- New, weeks later. Possible inflammatory or product nodule, particularly after PDLLA; see lumps after filler for how late lumps are assessed.
- Pale, dusky or mottled skin, or any change in vision. Rare with superficial boosters, but an emergency; see below.
Small flares of acne or a cold sore in the treated area can also happen in the days after; they are treated in their own right, and an active cold sore or infection is a reason to reschedule treatment.
When to seek urgent help
Skin boosters are placed superficially, so these signs are rare after them. They are still an emergency when they happen, particularly with deeper boosters or treatment near the eyes, because they can mean that product is affecting a blood vessel.
- Skin that turns pale or white (blanching) during or soon after the injection
- Severe pain, or pain that keeps increasing, rather than settling
- Mottled, dusky, blue-grey or purple patches, often in a net-like or branching pattern
- Any change in vision: blurring, a shadow, double vision, loss of part of the visual field, or eye pain
- Swelling of the lips, eyes or throat, or difficulty breathing: call 995 or go to the nearest emergency department
What to do: contact the clinic that treated you immediately, by phone or WhatsApp, and say that you have had filler and what you are seeing; a photograph helps. For any change in vision, go to the nearest emergency department straight away (in Singapore, call 995 if you cannot get there safely). Do not wait to see whether it settles, and do not try to treat it yourself at home.
IN Eternity Clinic patients: WhatsApp or call +65 8815 3008. If you were treated elsewhere, contact that clinic first, because they know which product was used and where; if you cannot reach them, seek medical care without delay.
Can skin boosters cause pigmentation, acne or infection?
Occasionally. A bruise or inflamed bump can leave a brown mark on darker skin, the treated area can flare with acne or a cold sore, and any injection carries a small infection risk.
In Singapore’s humidity and sun, post-inflammatory pigmentation after a bruise is the commonest of these on skin types III to V. It usually fades over weeks with sun protection and gentle care. Clean technique, skin antisepsis and single-use sterile needles and cannulas lower the infection risk. Active acne, infection or a cold sore in the area are settled first.
A different booster may suit sensitive or acne-prone skin better, and for people who prefer to avoid needles, a needle-free option such as the Deep Synergy Booster, which uses ultrasound delivery, can be discussed.
What Dr Sin Yong looks for
- Which booster family suits the concern, since hydration, repair and collagen stimulation are different jobs with different downtime.
- Skin thickness and the area: thin skin around the eyes and on the neck needs thinner products and smaller, evenly spread amounts.
- Active acne, infection, eczema or a cold sore in the area, which are settled before treatment.
- Upcoming events, so that bumps and any bruise have time to settle, and a week is allowed for PDLLA.
- Earlier filler or boosters in the same area, and any history of nodules after injectables.
General clinical observations used at consultation; they describe what is checked, not any individual result.
How are skin booster side effects reduced?
Side effects are reduced by matching the booster to the skin, placing it at the right depth in even, modest amounts, and simple preparation and aftercare.
- Before: avoid alcohol for a day; pause optional supplements that thin the blood, such as fish oil, if your doctor agrees; reschedule if you have a cold sore or skin infection.
- During: numbing cream; a fine needle or cannula chosen for the area and bruising risk; even spacing so that no spot is overloaded.
- After: a cold compress, no pressing or rubbing of the bumps, gentle skincare, sun protection, and covering any bumps gently if needed.
Results vary between products, and the evidence for some is still developing [4], which is another reason to choose a booster for a clear reason rather than by trend. If a lump from an earlier hyaluronic acid treatment needs correcting, see filler correction; how boosters compare with collagen injections is on collagen injections.
Frequently asked questions
How long do skin booster bumps last?
Usually from a few hours to three days. Rejuran and fine hyaluronic acid droplets tend to flatten within hours to a day or two, Profhilo leaves a few larger bumps for a day or two, and PDLLA bumps settle within hours to a day or two but can bruise. Bumps lasting beyond a week should be reviewed.
What are the side effects of Rejuran?
Mainly small bumps and redness at each injection point, which usually flatten within hours to a day, plus small bleeding points and occasional bruising. Less often there is an acne or cold sore flare. Bumps lasting more than a week need review, and swelling of the lips, eyes or throat is an emergency.
Is it normal to have lumps after Profhilo?
A few larger bumps at the five injection points on each side are normal and usually spread out within a day or two. A firm lump that is still there after a week is not typical and should be reviewed; because Profhilo is hyaluronic acid, it could be dissolved if needed.
Can I go to work after a skin booster?
Most people can, although small bumps may be visible at close range for a day and a pinpoint bruise may need concealer. For PDLLA such as Juvelook, allow at least a week before an important event. Make-up is usually fine from the next day once the entry points have closed.
Do skin boosters cause bruising?
Sometimes. Pinpoint bruises at injection points are common and usually fade within about a week. Bruising is more likely around the eyes and along a cannula track. Avoiding alcohol for a day and, if your doctor agrees, pausing optional supplements that thin the blood can help.
Can skin boosters cause pigmentation on darker skin?
Injected boosters are not heat or light treatments, so pigment risk is low. However, a bruise or inflamed bump can occasionally leave a brown mark on skin types III to V that fades over weeks. Sun protection and gentle aftercare help, particularly in Singapore’s sun.
Can skin booster lumps be dissolved?
Hyaluronic acid boosters such as Profhilo and microdroplet hyaluronic acid can be dissolved with hyaluronidase if a lump persists. Polynucleotides such as Rejuran and PDLLA such as Juvelook cannot, so a persistent lump is examined first and treated according to its cause.
Which skin booster has the least downtime?
Among injected boosters, polynucleotides and fine hyaluronic acid droplets usually settle fastest, often within a day. A needle-free option such as the Deep Synergy Booster, delivered by ultrasound, leaves no needle bumps, trading some precision for that. The right choice depends on the skin concern, not downtime alone.
Book an assessment
IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, Singapore 228210. By appointment with Medical Director Dr Sin Yong. Monday to Saturday, 11am to 8pm. WhatsApp or call +65 8815 3008. At IN Eternity Clinic a consultation fee applies, and it is waived if you go ahead with any medical treatment; the fee is S$120.
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References
- Sparavigna A, Cigni C, Tanzini L, Lualdi R, Grimolizzi F. A systematic review of the efficacy and safety of Profhilo and Profhilo Body. Plast Aesthet Nurs (Phila) 2026;46(2):80-92. doi:10.1097/PSN.0000000000000637
- Sparavigna A, Tenconi B. Efficacy and tolerance of an injectable medical device containing stable hybrid cooperative complexes of high- and low-molecular-weight hyaluronic acid: a monocentric 16 weeks open-label evaluation. Clin Cosmet Investig Dermatol 2016;9:297-305. doi:10.2147/CCID.S114450
- Park KY, Seok J, Rho NK, Kim BJ, Kim MN. Long-chain polynucleotide filler for skin rejuvenation: efficacy and complications in five patients. Dermatol Ther 2016;29(1):37-40 (online 2015). doi:10.1111/dth.12299
- Lee KWA, Chan KWL, Lee A, et al. Polynucleotides in aesthetic medicine: a review of current practices and perceived effectiveness. Int J Mol Sci 2024;25(15):8224. doi:10.3390/ijms25158224
- Cavallini M, Bartoletti E, Maioli L, et al. Consensus report on the use of PN-HPT (polynucleotides highly purified technology) in aesthetic medicine. J Cosmet Dermatol 2021;20(3):922-928 (online 2020). doi:10.1111/jocd.13679
- Rho NK, Kim HS, Kim SY, Lee W. Injectable “skin boosters” in aging skin rejuvenation: a current overview. Arch Plast Surg 2024;51(6):528-541. doi:10.1055/a-2366-3436
- No YA, Seok J, Hyun MY, et al. Long-term (24-month) safety evaluation of poly-DL-lactic acid filler injection for the nasolabial fold. Plast Reconstr Surg 2015;135(6):1074e-1075e. doi:10.1097/PRS.0000000000001247
- Lin CY, Lin JY. Retrograde flow phenomenon of poly-D,L-lactic acid filler injection over lower eyelids. Skin Health Dis 2024;4(3):e377. doi:10.1002/ski2.377
- Seo SB, Wan J, Yi KH. Energy-based device management of nodular reaction following poly-D,L-lactic acid injection for tear trough rejuvenation. J Cosmet Dermatol 2025;24(1):e16575 (online 2024). doi:10.1111/jocd.16575
- Cavallini M, Gazzola R, Metalla M, Vaienti L. The role of hyaluronidase in the treatment of complications from hyaluronic acid dermal fillers. Aesthet Surg J 2013;33(8):1167-1174. doi:10.1177/1090820X13511970
These sources describe mechanisms and general evidence. They are not a promise of any individual result; suitability is decided at an in-person assessment.