How it differs from hyaluronic acid

1.5.1Two different molecules

Hyaluronic acid is a glycosaminoglycan, a long chain of repeating sugar units. It is present in human skin, joints and eyes, and it is extremely good at binding water. Injectable hyaluronic acid products are manufactured by bacterial fermentation and then, in most cases, chemically cross linked, which ties the chains together so that the resulting gel resists enzymatic breakdown for months rather than days.

Polynucleotides are nucleic acid, not sugar. They are extracted rather than fermented, fragmented rather than cross linked, and designed to be broken down rather than to persist. Where a hyaluronic acid filler is engineered for durability, a polynucleotide product is engineered for controlled disappearance.

1.5.2Reversibility, which is the difference that matters most

Hyaluronidase is an enzyme that breaks down hyaluronic acid. Its availability is the reason hyaluronic acid became the dominant filler material, and it is the reason a serious complication involving a hyaluronic acid filler, including vascular occlusion, has an immediate specific response available. It is not a magic eraser, it has its own risks, and using it well requires training. But it exists.

There is no equivalent for polynucleotides. If the result is not what you wanted, if a lump forms, or if the product is placed poorly, the available responses are time and symptomatic management. This is not a reason to avoid the treatment. It is a reason to take the assessment, the practitioner's experience and the placement decision more seriously, because the correction route that exists for the adjacent category does not exist here.

1.5.3The comparison people actually mean

When patients compare polynucleotides to hyaluronic acid they usually mean skin boosters rather than volumising fillers. Skin boosters are thin, minimally cross linked or uncross linked hyaluronic acid products injected in multiple small deposits to hydrate rather than to shape. Superficially the treatment experience is similar: multiple small injections over a wide area, a course of sessions, maintenance afterwards.

The claimed difference is one of mechanism. A hyaluronic acid skin booster is understood to work substantially by holding water, an effect that is physical, immediate and undisputed as far as it goes. A polynucleotide product is claimed to work by influencing the cells in the dermis, which if true would mean the effect outlasts the material. That is the interesting claim and it is also the one that carries the weight of the category. It is worth being clear that the interesting claim and the well supported claim are not the same claim.

1.5.4Using both

Clinics frequently offer them together or in sequence, and some products combine them in one syringe. There is nothing inherently wrong with that, and combining a hydrating agent with a claimed biostimulatory one is a reasonable clinical idea. Two consequences follow for the patient.

The first is evidentiary. If two things are done at once, neither you nor your practitioner can attribute the result to either. That does not matter if you are content with the outcome. It matters a great deal if you are deciding what to repeat, because you will be paying to repeat both.

The second is practical. A combined product is a different product with a different regulatory file and a different complication profile, and a reaction to it cannot be attributed to one component without further investigation. Ask what is in the syringe and, if two things are being done in one session, ask whether they could be separated.

1.5.5A framework for choosing between them

There is no evidence based ranking to offer, and inventing one would be exactly the sort of thing this reference exists to avoid. What can be offered is a set of considerations that point in different directions.

• If reversibility matters a great deal to you, that consideration points towards hyaluronic acid, because a specific corrective agent exists.
• If your concern is volume or contour, polynucleotides are not the relevant category at all. They are not intended to change shape.
• If you avoid animal derived products, hyaluronic acid injectables are generally produced by bacterial fermentation, whereas polynucleotide products are generally fish derived.
• If you are drawn by the regenerative claim specifically, that is the claim with the least secure evidence behind it, and the chapter on evidence is the part of this document to read before deciding.
• If you have had a poor experience with hyaluronic acid, that is a matter for a clinician who knows the details, not a reason to switch categories on the basis of a website.

1.5.6Being fair to both

Category rivalry produces bad information in both directions. Pages selling polynucleotides describe hyaluronic acid as a passive filler that merely occupies space, which understates what a well placed skin booster does. Pages selling hyaluronic acid describe polynucleotides as unproven, which is closer to accurate but is being said by an interested party.

The position this reference takes is narrower than either. Hyaluronic acid holds water, that is well established, and it can be reversed. Polynucleotides also hold water, and are additionally claimed to do something more interesting that has not yet been demonstrated to the standard the claim requires. Those two statements are compatible, and holding both is more useful than picking a side.