Key facts
- Hyaluronic acid (HA)
- A water-binding molecule placed in the dermis to hydrate and support the skin
- Polynucleotides (PN)
- Purified DNA fragments, usually from salmon, directed at the repair environment of the dermis
- PLLA
- Poly-L-lactic acid scaffold that prompts your own collagen; a biostimulator, not a hydrator
- What none of them is
- A filler: none lifts descended tissue, clears pigment or shrinks a pore
- Reversal
- Hyaluronidase acts on hyaluronic acid only; it has no effect on PLLA
- Choosing between them
- By what the skin is short of, decided at examination, not by brand name
- Worth asking
- The product name, its category, whether it is HSA-registered and who is injecting
What are the main types of skin booster?
There are three main families, and they are named by their molecule rather than their brand. Hyaluronic acid boosters hydrate the dermis. Polynucleotide boosters, such as Rejuran, are directed at how the skin repairs itself. Poly-L-lactic acid is a collagen biostimulator, sometimes marketed beside boosters although it works on structure rather than surface quality.
The label skin booster is a category, not a product. It covers injectables placed into the skin to change its quality, such as hydration, texture and elasticity, rather than its shape. Under that label sit materials that behave very differently, and nicknames such as the Chanel injection or salmon DNA injection describe a source or a rumour rather than a mechanism.
The useful habit is to translate every name back to its molecule: what is in the syringe, where it is placed and what it is meant to do. The site's guide to skin booster brands explained covers the names; this page covers the molecules behind them.
Because the three families answer different questions, choosing between them is not a ranking. Dull, dehydrated skin is a hydration question; thin, fragile or textured skin is a repair question; a deflated mid-face is a structure question. A family that is right for one of those questions is simply the wrong tool for another, and the skin booster treatment page sets out how the classes are chosen.
What does hyaluronic acid do in the skin?
Hyaluronic acid binds water, and when it is placed in the dermis it holds that water in the tissue itself. A plain HA booster is soft and non-cross-linked or lightly stabilised, so it spreads through the skin instead of holding a shape. It is directed at dull, dehydrated skin and fine surface lines, which is a skin quality complaint rather than a structural one.
Profhilo sits inside this family but behaves differently from a conventional booster. It is hybrid HA, bonded thermally rather than with a chemical cross-linker, designed to spread through tissue planes and stimulate as well as hydrate. It remains a skin quality treatment: it does not give projection or structure, and it is separate from Profhilo Structura, which is a different product.
HA is broken down by the body over time, so the skin resumes its own course once the material has gone. That is also why reversal is possible for HA in principle, because hyaluronidase acts on hyaluronic acid and nothing else.
A needle-free route belongs in this conversation only in a limited sense. The Deep Synergy Booster delivers its actives from the surface using focused ultrasound, so it cannot place product at a chosen depth the way an injectable can. Serums sold as boosters for home use are cosmetics, and large molecules cross intact skin poorly, so they are not the same intervention as an injected material.
“A skin booster treats the quality of the skin. A filler occupies space. Confusing the two is the most common error patients arrive with.”
Dr Sin YongOn the difference between a booster and a filler
How are polynucleotides different from HA?
Polynucleotides are directed at repair rather than hydration. They are purified DNA fragments, usually from salmon, placed into the dermis by micro-injection. Purification means what is injected is the polymer, not genetic information. The literature describes an influence on fibroblast activity and the extracellular matrix, which is why they are considered for texture, fine lines and thin, crepey skin.
The terms PN and PDRN are not synonyms. PN refers to longer chains and PDRN to shorter fragments of the same family, and products built on each differ in concentration, viscosity and intended use. Rejuran is the polynucleotide product used at this practice, and it is registered with Singapore's Health Sciences Authority as an injectable medical device.
Practical differences show on the day. Small raised points at the injection sites occur with every booster, but they tend to be more noticeable at first with polynucleotides. Because the material is fish-derived, a fish or salmon allergy is raised before any polynucleotide is considered.
How each family is judged also differs. An HA booster may give a hydrated look soon after treatment, whereas collagen-directed families such as polynucleotides and PLLA work gradually, so their effect is judged later rather than in the first days. Laboratory findings explain the idea behind a product, but they are not a prediction of what an individual's skin will do.
Skin booster families compared by molecule| Family | What it does | What it cannot do | Who it tends to suit |
|---|
| Hyaluronic acid booster | Hydrates and supports the dermis | Add volume, lift tissue or treat pigment | Dull, dehydrated skin with fine surface lines |
| Profhilo (hybrid HA) | Spreads through tissue planes; hydrates and stimulates | Give projection or structure like a filler | Early crepey skin quality, face, neck and hands |
| Polynucleotides (PN) | Directed at dermal repair and the extracellular matrix | Add volume, lift or remove pigment | Thin or textured skin where repair is wanted |
| PLLA biostimulator | Prompts your own collagen around a scaffold | Hydrate the surface; it cannot be dissolved | Diffuse structural loss, with patience for gradual change |
| Dermal filler (for contrast) | Occupies space to restore volume or contour | Improve the quality of the skin itself | Hollows and contour loss |
Where does PLLA fit, and why is it different?
PLLA is a scaffold, not a hydrator. Poly-L-lactic acid microparticles sit in the deeper dermis or subdermal plane, and fibroblasts respond by laying down new collagen over time. The change is gradual and structural, which is why PLLA, along with PCL and calcium hydroxylapatite products, is grouped as a collagen biostimulator and not as a skin booster.
The planning consequence is the important one. PLLA cannot be dissolved with hyaluronidase, so dosing is conservative and staged, and a misplaced or overdone product can only be managed while it biodegrades. It is aimed at diffuse volume loss and firmness in the mid-face, temples and jawline, not at surface dullness, and it does not suit lips, tear troughs or fine lines.
The full discussion, including the products used and how correction is approached, sits on the collagen biostimulators page. For a face with both crepey skin and a deflated mid-face, the booster and the biostimulator do different jobs and are sometimes sequenced, with the order decided at assessment.
Which type suits which skin, and who should wait?
The family follows the finding. Dull, dehydrated skin with fine surface lines points to hyaluronic acid. Thin, fragile or textured skin where repair rather than volume is wanted points to polynucleotides. Diffuse structural loss points away from boosters altogether, towards a biostimulator or a filler, and that is a different conversation.
A booster is deferred when there is active infection, a cold sore, an acne flare or eczema at the injection sites, and in pregnancy and while breastfeeding. It is not used in anyone allergic to a component: hyaluronic acid, or fish for polynucleotides. Caution rather than refusal applies to autoimmune disease, a keloid tendency, a bleeding tendency or blood-thinning medicines, and a recent laser or peel changes the timing.
No booster is the right category when the main concern is a hollow, descended tissue, a tethered scar or pigment. Boosters address none of those, whatever their name, and a doctor who explains that is protecting you from the wrong treatment.
Boosters are often planned alongside other work rather than instead of it. Where pigment is the presentation, a laser approach applies; where the problem is descent, energy-based lifting is the relevant tool; where scars are tethered, subcision and resurfacing are matched to the scar type. A booster may sit beside any of these to support skin quality, but it does not substitute for them.
What are the risks, and when should you call?
Every booster is an injection and carries injection risks. Small raised points, redness, swelling, tenderness and bruising are expected and settle on their own. Less commonly there are lumps where product sits unevenly, a bluish tint where HA lies too close to the surface, a flare of cold sores, or infection.
Delayed inflammatory reactions, appearing as tender swelling after a period, are rare, as are allergic reactions. Any injectable carries a small risk of product entering a blood vessel; with fine superficial placement it is uncommon, but pain, blanching or dusky skin after treatment needs prompt attention. Increasing swelling, heat or pain, rather than settling, is a reason to call the clinic the same day.
Risk is reduced by choosing the family for the skin, sterile technique, correct depth for each product, and treatment by a doctor who can manage a complication. The page on complication care sets out what to do if something feels wrong.
What determines the fee for a skin booster?
Singapore rules prevent clinics advertising prices, so this page gives factors rather than figures. The fee follows the plan: the family of booster indicated, the area treated, whether one family or several are combined, and how the plan is staged over time.
The same complaint can have different causes, so a figure quoted before assessment would not reflect your skin. A written quote is given at consultation after examination, before anything is agreed, and the consultation also decides whether a booster is advised at all. How quotes work is explained on the how we quote page.
