What a polynucleotide visit involves, preparation by preparation, is set out under Rejuran treatment.
What a poly-D,L-lactic acid and hyaluronic acid injectable involves is covered under Juvelook treatment.
Published 31 October 2026 · Reviewed by Dr Sin Yong
What to expect at a skin booster visit with Dr Sin Yong is a choice before an injection: the skin is examined, the class of booster is chosen by what the skin is short of, and allergies to hyaluronic acid, lidocaine or fish are asked about directly. Numbing cream is usually applied, product is placed through fine needles, and small raised points follow and settle.
Short answerSkin booster is a name for several classes that do different jobs: hyaluronic acid boosters, Profhilo, polynucleotides such as Rejuran, and PDLLA such as Juvelook. What happens at the visit is similar; which class you receive is the decision that matters. This page sits under skin boosters in Singapore.
Before any booster is placed, Dr Sin Yong examines the skin himself and chooses the class by what the skin is short of. A booster changes skin quality, meaning hydration, elasticity and texture; it adds no volume and changes no shape. A hollow is assessed for filler and descended tissue for lifting instead, and that is said at the assessment rather than after the injections.
Illustrative image — not a patient.
Concern
Class usually weighed
Asked about first
Dry, dull, dehydrated skin with fine surface lines
A hyaluronic acid skin booster
Hyaluronic acid or lidocaine allergy
Early loss of firmness, crepey skin
Profhilo bio-remodelling
Hyaluronic acid allergy
Thin, fragile skin and fine texture
A polynucleotide, such as Rejuran
Fish allergy, because it is purified from salmon DNA
Gradual firmness and texture change
A PDLLA biostimulator, such as Juvelook
Earlier filler, because PDLLA cannot be dissolved
Before the visit, declare allergies, blood-thinning medicines and supplements, and any autoimmune condition; tell the clinic if you are pregnant or breastfeeding, or have a cold sore, acne flare or eczema; mention any recent laser, peel, filler or threads in the area; avoid tanning; and bring photos of past injectable treatments. Which booster suits which skin is set out on am I suitable for a skin booster.
How is a skin booster placed at the visit?
Numbing cream is usually applied first, and some products also contain a local anaesthetic. Product is then placed through fine needles in a pattern set by the product and the area. A hyaluronic acid booster is placed as many small injections into the dermis. Profhilo is placed as a small number of deposits at defined points and left to spread; Dr Sin Yong uses a modified BAP, keeping the defined points as the safety framework and adding placement where the face shape demands it, including into scarred skin. A polynucleotide is placed in the dermis by micro-injection, by hand or with an injector device at a set depth.
Most people feel a series of small pricks with some stinging or pressure. The skin around the eyes and over scars tends to be more sensitive. Placement at the right depth for each product is part of keeping the risks low: hyaluronic acid that lies too close to the surface can give a bluish tint, and product that sits unevenly can form a lump. Comfort is checked as the treatment goes on, and you can ask to pause at any point.
“A skin booster treats the quality of the skin. A filler occupies space. Choosing the class at the assessment matters more than anything that happens with the needle.”
Dr Sin YongOn what decides a skin booster visit
What happens straight after a skin booster, and what needs a call?
These are phases, not a timetable: how quickly each passes depends on the product, the area and the person.
Immediately after. Small raised points where product was placed, with redness and occasionally a bruise.
The first evening. Avoid make-up, heat, alcohol and strenuous exercise; a cool compress limits swelling.
The following phase. Bumps flatten and redness fades. A hyaluronic acid booster may give an early hydrated look.
As the skin settles. Collagen-directed classes, PDLLA and polynucleotides, work gradually, so their effect is judged later rather than in the first phase.
How visible the early bumps are depends on the class: polynucleotides tend to leave more noticeable bumps at first than a hyaluronic acid booster. Specific instructions are given on the day, because they differ slightly between products.
What needs a call
Pain that is getting worse, or skin that turns pale or dusky: urgent assessment by the doctor who injected you, or at A&E, now.
Increasing swelling or heat: a doctor the same day; if no doctor can see you today, A&E.
A flare of cold sores, or a tender swelling that appears later.
The plan is reviewed after the initial phase. Dr Sin Yong examines the skin once the early bumps have gone and decides what follows from what the skin has done: nothing further, a maintenance placement, or a different class. How the initial and maintenance phases are staged is part of the written plan and the fee factors on skin booster cost factors.
A bump that is still there once the rest of the skin has settled is scanned before anything is decided, because filler or another booster placed earlier can sit in the same area. Hyaluronic acid can be dissolved with hyaluronidase; PDLLA and polynucleotides cannot, which is why they are placed with care and why a lasting lump is assessed with ultrasound first, as set out on skin booster lumps.
Where a booster is combined with laser, energy-based lifting or filler, the order and spacing are set so that each treatment is given at a sensible point in healing. The evidence for injectable hyaluronic acid on skin quality is encouraging but early: a 2023 systematic review of 13 studies described it as safe with high satisfaction and called for large randomised trials.
Your next step
1. MessageWhatsApp +65 8023 7170 with what is bothering you. A reply comes from the clinic, not a bot.
2. AssessmentDr Sin Yong examines you himself on Orchard Road, with ultrasound where earlier filler is involved.
3. A plan in writingWhat he would do, what he would not, the fee factors, and the option of no treatment.
Every treatment is performed by Dr Sin Yong personally. Singapore Medical Council registered · invited to share his clinical expertise internationally for CLASSYS, DEKA, Fotona, Hironic and Ilooda.
Book an assessment with Dr Sin Yong on Orchard Road; tell the clinic about any allergy to hyaluronic acid, lidocaine or fish. How consultations work.
Numbing cream is usually applied before skin booster injections, and some products also contain a local anaesthetic. Most people feel a series of small pricks with some stinging or pressure, and the skin around the eyes and over scars tends to be more sensitive than the cheeks. Comfort is checked during treatment, and you can ask Dr Sin Yong to pause at any point.
Small raised points where product was placed are expected after a skin booster, with redness and occasionally a bruise. How visible they are depends on the class: polynucleotides such as Rejuran tend to leave more noticeable bumps at first than a hyaluronic acid booster, and Profhilo leaves a bleb at each defined point. They flatten as the skin settles.
That is decided at the assessment, by what your skin is short of rather than by brand. Dry, dehydrated skin points to a hyaluronic acid booster, crepey skin to Profhilo, thin and fragile skin to a polynucleotide, and gradual firmness to a PDLLA biostimulator. Allergies to hyaluronic acid, lidocaine or fish can rule a class out, so they are asked about first.
A recent laser or peel in the area changes the timing of a skin booster, as does recent filler or threads. Where a booster is part of a plan with laser, energy-based lifting or filler, Dr Sin Yong sets the order and spacing so that each treatment is given at a sensible point in healing. Tell the clinic what was done recently and when.
Avoid make-up on the first evening, along with heat, alcohol and strenuous exercise, while the raised points are present and the injection points are fresh. Once the points have closed and the bumps are settling, make-up can usually resume. Specific instructions are given on the day, because they differ slightly between products.
References
The Effectiveness of Injectable Hyaluronic Acid in the Improvement of the Facial Skin Quality: A Systematic Review. Clinical, Cosmetic and Investigational Dermatology 16, 2023. source
The Effectiveness of Polynucleotides in Esthetic Medicine: A Systematic Review. Journal of Cosmetic Dermatology 24(2), 2025. source
About this page: written and medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last reviewed 6 November 2026 · Illustrative images only, not patients · Editorial policy
