What it is
They ask the skin to repair itself and to make its own collagen, so what changes, changes gradually across a course rather than on the day of treatment. Polynucleotides are purified DNA fragments, usually from salmon or trout, injected into the skin to support repair, hydration and elasticity; collagen biostimulators — poly-L-lactic acid, calcium hydroxylapatite, polycaprolactone — are placed deeper, to rebuild support and firmness where the face has flattened.
What this page covers
- Polynucleotide (PDRN) injection of the face and the under-eye area
- Poly-L-lactic acid collagen stimulation
- Calcium hydroxylapatite for contour and collagen response
- Hyperdilute calcium hydroxylapatite for skin thickness and crepiness
- Polycaprolactone biostimulation (registration to be confirmed)
- Hybrid hyaluronic acid with calcium hydroxylapatite (registration to be confirmed)
- Subcision with a biostimulator for rolling acne scars
- Post-weight-loss facial volume restoration
- Hand rejuvenation on the back of the hand
- Skin quality assessment and biostimulator treatment planning
- Management of late nodules and delayed inflammatory reactions
Who it suits
- Someone whose complaint is the quality of the skin itself — thin, dull, finely crepey — and who accepts that polynucleotides work by repair rather than by filling, and that the effect accumulates across a course rather than appearing on the day.
- Someone who has lost diffuse support across the face rather than volume at one point, and who accepts two conditions together: that the plan is carried out in stages, and that collagen biostimulators are not dissolved the way hyaluronic acid is — what is placed stays until the body absorbs it.
- Someone who can tell us everything already injected into her face — where, when and with which material — including what was done at another clinic or outside the country. A biostimulator is not injected on top of an unidentified previous product.
- Someone content to be asked about allergy before every session rather than only the first, and to be told plainly that polynucleotides are derived from fish — salmon or trout — before the syringe is drawn rather than after.
- This is not for you if what troubles you is lax skin itself or a hollow under the eye. These injections do not fill a hollow and do not lift skin that has become lax, and hyperdilute calcium hydroxylapatite is marketed as a non-surgical lift when it is not one. Where the finding is descent or excess skin, the route is skin tightening or a surgical opinion.
When we advise delaying or not treating
- Pregnancy and breastfeeding — we postpone. These are elective treatments, and waiting costs you nothing.
- Fish or seafood allergy. Polynucleotides are not given. A documented allergy history is taken before every session rather than only the first, and the questions include hair dye and black henna, and the acrylates in gel and acrylic nails — the two sensitizers most often left unmentioned here.
- Active infection or inflammation in or near the area, and active acne, which is controlled before any work on the skin.
- Autoimmune and connective-tissue disease in an active phase. A bleeding tendency and blood thinners are reviewed, and no medicine is stopped for an aesthetic reason without the agreement of the doctor who prescribed it. Poorly controlled diabetes is deferred: it raises the risk of infection and poor healing in anything that breaks the skin.
- Current or recent isotretinoin treatment.
- A known tendency to keloid scarring. It is asked about before any procedure that breaks the skin, and it changes not only the decision to start but what would be done later if a nodule appeared.
- Skin thinned by an unlabeled lightening cream or mixed preparation — that is treated first, and bring the container with you. And an area threaded, waxed or sugared within the last few days — we postpone.
- A previous material in the same plane that we cannot identify. We do not inject on top of it; some of these cases need assessment, imaging or referral rather than another injection.
- The lips and the area around the eyes: the collagen biostimulators — poly-L-lactic acid, calcium hydroxylapatite and polycaprolactone — are kept away from them because of the nodule risk. A request for a biostimulator in the lip or the tear trough is one we decline. Polynucleotides around the eye are a separate question, decided at the examination.
- Under eighteen: elective biostimulators are not offered, and an adolescent brought for a medical skin problem is assessed with a guardian present while the aesthetic question is deferred.
- A request to do everything in one session, or days before an occasion. We decline: spacing is what reduces the chance of nodules, and bruising around the eye and swelling of the hands show for days.
- A request for a lift. These injections work on the quality of the skin and on its support; they do not lift what has become lax, and visible neck bands and excess skin will not respond — we say so rather than try.
- A request for a particular product seen online. We tell you honestly whether it is registered and available here at all; registration of polycaprolactone and of the hybrid products in Saudi Arabia is still to be confirmed, and what is unconfirmed is not offered.
- After major weight loss or bariatric surgery: the weight is allowed to settle and the nutritional picture is reviewed — iron, ferritin, B12, folate, zinc, vitamin D and protein — before any stimulation is planned. A face hollowed by deficiency is not treated with injections.
Possible effects
Stated in full, because the decision is not sound without them. This page holds two families rather than one: polynucleotides are injected into the skin and absorbed by the body, while collagen biostimulators are placed deeper and are not dissolved. What can go wrong differs between them, and the heaviest fact about the second family is that hyaluronidase — the enzyme that dissolves hyaluronic acid filler — does nothing to them, neither in correcting a result nor in an emergency.
- With polynucleotides: papules at the injection points are expected and settle over days, along with swelling and bruising. Bruising around the eye shows for days, and swelling on the backs of the hands can last days as well.
- Pigmentation at the injection points is possible in Fitzpatrick III to VI skin, and particularly on the neck and upper chest — see the paragraph below.
- Infection at an injection site: uncommon, and needing early review whenever the pain increases, the redness spreads or warmth appears.
- Allergic reaction: polynucleotides are derived from fish and can cause a reaction that, rarely, reaches anaphylaxis. That is why allergy is asked about before every session, and why this class of product is injected only where emergency drugs, a written plan and someone who knows how to begin are all present.
- Nodules and delayed inflammatory reactions after a biostimulator: the principal concern. They can appear weeks or months after the last session, some are felt rather than seen, and they are associated with injection into too superficial a plane, with too much at one sitting, or with inadequate preparation or massage. Telling a simple nodule from an infection or a biofilm changes the treatment entirely, which is why it is examined before anything is injected into it.
- What cannot be dissolved: poly-L-lactic acid, calcium hydroxylapatite and polycaprolactone respond to hyaluronidase in no way at all. What is placed wrongly cannot be drawn back, and the options are then local treatment, time or — rarely — surgical removal, with recovery slower and less complete than it is with hyaluronic acid filler. In the hybrid products only the hyaluronic acid part dissolves and the rest stays.
- Hyperdilute calcium hydroxylapatite placed more superficially than it should be can leave visible white nodules or a pale look beneath the skin, and thin neck skin is unforgiving of superficial placement. Polycaprolactone lasts longer, so an imperfect result also lasts longer.
- Vascular occlusion: product entering an artery or pressing on one, so that blood stops reaching the skin. It begins with severe pain out of proportion to the procedure, then blanching or blue or gray mottling, and it can end in necrosis — part of the skin dying, peeling and leaving a scar. Product can also be pushed into an artery against the flow of blood and reach the vessels supplying the eye, causing loss of vision, a rare and recognized complication after facial injection. The difference that belongs to this page is that an occlusion caused by a biostimulator has nothing that will dissolve it, and is harder to manage than one caused by hyaluronic acid. What should be done is written in the box at the top of this page.
- Asymmetry or surface irregularity: managed by working gradually and reviewing. And the result is not judged early; judging it too soon is what leads to over-treatment.
A note on darker skin
Most of the skin treated here is Fitzpatrick III to VI, and that is the fact the plan is built on rather than a footnote added to it. The material is not chosen by skin tone, but four things change. The first is in your favor: these injections are neither light nor heat, so they do not carry the risk of a burn or the pigment change that devices carry, which makes intradermal work among the gentler options for deeper skin — though the needle itself can still leave post-inflammatory pigmentation at the injection points, particularly on the neck and upper chest, which is why photoprotection afterward is part of the treatment rather than an optional extra, and why the marks are reduced by fewer entry points, by a cannula where it suits, and by treating bruising early. The second is that work on acne scarring in Fitzpatrick III to VI frequently passes through a period of darkening before it improves, which is said before starting rather than after, and that depression is separated from post-inflammatory pigmentation first, because their routes are not the same. The third is that combining these injections with energy devices is spaced further apart here and staged more slowly, because injecting into freshly heated skin raises the chance of a nodule and of pigmentation together. The fourth is that a tendency to keloid scarring is more common in these skin types, and it changes not only the decision to start but the threshold for intervening if a nodule appears later, since repeated incision and drainage is no small decision in skin disposed to keloid. And the part rarely said out loud: blanching and then mottling are among the early signs of a vascular occlusion, and a change in color is harder to read on deeper skin, so it can be caught late — not because the risk is lower but because the sign is quieter. Do not wait to see the color: severe pain out of proportion is reason enough on its own to ask for help, and it usually comes first.
Afterwards
- Massage the area as you are asked to and for the period you are given, where the material is one that needs it; following that is part of reducing the chance of nodules. Where you are not asked to massage, do not massage.
- Papules at the injection points are expected and settle over days. And the result is not judged early.
- Avoid high heat, strenuous exercise and makeup for the period you are told.
- Sun protection is daily and strict. Do not restart an unlabeled lightening cream over freshly injected skin, and you are told when you may go back to threading, waxing or sugaring the area.
- If you have an occasion coming up, the right answer is for us to postpone the session rather than to reassure you: bruising around the eye and swelling of the hands show for days.
- Keep the written warning-sign sheet and a way of reaching us outside working hours. If you have diabetes, wound-care and infection instructions are given explicitly rather than assumed.
Tell us about any pain that increases instead of settling, redness and warmth that spread, a fever, or a lump appearing weeks or months after the injection, even one you can feel but not see. A lump is examined first and nothing is injected into it before it is examined — and it is more straightforward to deal with when it is caught early. As for what is in the box at the top of this page — pain out of proportion, blanching or mottling of the skin, any change in vision, and the signs of a severe allergic reaction — do not wait for our reply after you tell us; tell us on your way to emergency care.
Honestly
Polynucleotides are fish-derived and are not given to anyone with a fish or seafood allergy, and the biostimulators cannot be dissolved the way hyaluronic acid can — late nodules are a recognized complication, so a wrong plane or a wrong candidate stays wrong until the body absorbs the product, which is why the agent, the depth and the candidate are all decided at examination and some patients are told this is not for them.
Common questions
Are 'collagen injections' and salmon injections the same thing?
No, and that is the first thing the consultation corrects. Polynucleotides — what people call salmon injections — are purified DNA fragments injected into the skin to support repair, hydration and elasticity, and the body absorbs them. Collagen biostimulators are placed deeper to rebuild support, and they include poly-L-lactic acid, calcium hydroxylapatite and polycaprolactone, none of which can be dissolved. One name in everyday speech, two families that differ in depth and in what can go wrong — which is why we always ask which one you mean.
Is it really made from fish?
Yes. Polynucleotides are extracted from salmon or trout and purified, and they are not given to anyone with a fish or seafood allergy. And if the source of the product matters to you for any reason at all, medical or not, say so and we will tell you what is in the syringe before it is drawn rather than after the session.
If I dislike the result, can it be dissolved?
That depends on the material. Hyaluronidase dissolves hyaluronic acid filler and nothing else. Poly-L-lactic acid, calcium hydroxylapatite and polycaprolactone do not dissolve, and what is placed stays until the body absorbs it. In the hybrid products the hyaluronic acid part dissolves and the rest stays. That fact alone is the reason for restraint in quantity and for spacing sessions, and you are entitled to know which material is in your plan and in which area.
A lump appeared months later, and I was told it can be dissolved.
It cannot, and that is exactly why having it examined first matters. Come and let us look at it: a simple nodule is one thing, an infection is another, the treatment differs completely between them, and so nothing is injected into it before it is examined. Do not press it or try to break it down yourself. A nodule can appear late and some are felt rather than seen, and it is more straightforward to deal with when it is caught early.
Will it fix my dark circles and the hollow under my eyes?
It does not fill a hollow. Polynucleotides around the eye work on the quality of that thin skin; they do not correct a hollow tear trough or fat that has come forward. And darkness under the eye is not always tired skin: we look first for kohl deposited at the lid margin and for the effect of a lash-growth serum before blaming the skin alone. The examination separates these, and the plan is entirely different depending on the cause.
I am pregnant, or breastfeeding.
We postpone. These are elective treatments by their nature, and there is nothing in them worth hurrying at either of those times. Come afterward and we will plan it without rushing.