Fillers or a Thread Lift?

Two Treatment Groups, Two Mechanisms

Fillers and lifting threads are often mentioned together, and are even presented as alternatives to each other. Yet they do not do the same job in the tissues. This difference is not a minor technical detail; it is exactly what determines which of the two is considered at a consultation.

Filler places a substance in the tissues. It takes up space in the layer it is injected into, supports the tissue above it from underneath and softens the contours that become more marked as volume is lost. In publications in this field, volume loss in the fat compartments is considered the starting point when planning treatment of the ageing face; replacing the lost volume is also planned according to how these compartments are distributed across the face.

A lifting thread, on the other hand, adds no substance; it carries a load. A barbed thread (a thread with small projections along it that grip the tissue) is placed under the skin, where it creates a supporting structure beneath the tissue and mechanically repositions tissue that has descended. Studies of dissolvable (absorbable) threads also report that a layer of connective tissue forms around the thread over time. However, it is not this layer that holds the tissue up, but the mechanical support provided by the thread.

In short, filler replaces what is missing, while a lifting thread moves back what has shifted out of place.

What Filler Does in the Tissues

Hyaluronic acid (HA) fillers are viscoelastic materials: under pressure, they behave like both a solid and a liquid. Research on the flow properties of these gels (their rheology) shows that this behaviour varies depending on how the gel is cross-linked, that is, how its molecules are bonded to one another: different gels respond differently to the same force. For this reason, the gel is chosen according to the injection area, the condition of the tissue and the intended effect. The point here is not a ranking of which gel is better, but which gel suits the area.

Filler works in two ways. The first is direct: the substance takes up space in its layer as soon as it is placed, so part of the effect is seen on the day of treatment. The second is indirect: gel placed in a deep layer changes the base on which the overlying tissue rests, and the appearance of the surface improves thanks to this base.

This second route has been discussed more in recent years. In some approaches, filler is planned not only to fill a hollow but also to support a specific layer. There is one point you should know, however: the source cited for this approach is not a comparative study but the shared opinion of an expert panel.

What Lifting Threads Do in the Tissues

The thread’s job is not to add volume but to reposition tissue. A barbed thread is passed under the skin; the barbs grip the tissue that has descended and carry it in the desired direction. This creates a supporting structure under the skin: the load is not concentrated at a single point but is spread along the line of the thread.

The material itself also matters. Studies of threads made from an absorbable copolymer (a combination of two substances) of poly-L-lactic acid (PLLA) and polycaprolactone (PCL) report that a layer of connective tissue develops around the thread and that this layer can remain after the thread has been absorbed. It is also stated, in cautious terms, that this layer increases the firmness of the tissue. These observations have two important limits. First, they are based on examining tissue samples under a microscope (histology), and these samples were taken from a very small number of patients; it is noted that more histology studies are needed in different areas of the face and in different patient groups. The second limit concerns the thread’s position: if the thread is placed in a more superficial layer than it should be, that is, in the dermis, a layer within the skin itself, it can be felt by hand and can become visible; in that layer, neither support nor collagen stimulation occurs to the expected degree. In other words, the lift comes from the mechanical support; the tissue response is not a substitute for it.

Most published case series have used absorbable threads; the most frequently studied materials are polydioxanone (PDO) and the copolymer of poly-L-lactic acid and polycaprolactone. There are fewer data on permanent (non-absorbable) threads, and the results for the two groups cannot be used in place of each other. Early treatments using non-absorbable barbed threads were reported to have high rates of complications and corrective procedures (revision). Techniques developed with absorbable threads are reported to cause fewer side effects; however, their long-term effectiveness is not clear. For this reason, this guide does not give a duration or longevity figure for any type of thread.

There is another distinction that is often asked about at consultations: a thread moves tissue, but it does not remove excess skin. If the main problem is excess skin, moving the tissue does not get rid of that excess.

Does Filler Really Lift?

This question is more debated than you might think. ‘Lift’ is one of the most commonly used outcome terms in filler studies. However, a review that examined this term critically shows that it has no agreed definition, no accepted measurement standard and no validated threshold above which a change counts as clinically meaningful.

Three observations stand out in this critique. First, all published measurements record change at the skin surface; there is no study in which the deeper structures were tracked separately. Second, the millimetre-scale effects reported are often no larger than the measurement error of the imaging method used, and in some cases they are even smaller than that error. Third, no direct proportional relationship has been found between the volume injected and the displacement measured.

This does not mean that ‘filler does not lift’; the critique itself states this clearly. What it says is this: the claim of lift is not defined precisely enough to carry the weight placed on it today. In practical terms, what you can expect from filler is a supported facial outline (contour) and replaced volume. Moving tissue that has descended back upwards is a separate question and requires a separate mechanism.

Why Does the Face Descend?

Sagging does not have a single cause. The retaining ligaments that hold the face in place loosen over time. In research, this loosening is linked with sagging, jowls (sagging along the jawline) and volume sliding downwards. So sometimes the problem is not volume that has been lost, but volume that has moved.

This distinction is decisive in practice. If volume really has decreased, it makes sense to replace it. If the volume is still there but has slid downwards, adding volume to the same area increases fullness but does not reverse the descent. The two situations can look similar from the outside; the difference between them becomes clear at a consultation.

The structure of the retaining ligaments varies from person to person; research stresses that even a surgical plan should be tailored to the individual on this basis. That is why there is no rule such as ‘at this age, you have this done’; what decides is not your age but the condition of the layers in your face.

If advanced laxity of the ligaments occurs together with marked excess skin, the question goes beyond a choice between filler and lifting threads. According to research, surgical techniques that release the ligaments extensively move the tissue further; with less invasive surgical techniques that preserve the ligaments, the correction of advanced laxity is more limited. This comparison was made between surgical techniques, not with non-surgical treatments. You should also know clearly that neither filler nor a thread lift is a substitute for surgery in which the tissue is extensively released.

Which Examination Findings Point to Which Treatment?

The choice starts with the examination findings, not with a method. A layer-by-layer assessment starts at the deepest level, with the bone and the retaining ligaments; it then moves on to the muscles, the ligaments and the superficial musculoaponeurotic system (the supporting layer that surrounds the facial muscles), and from there to the fat compartments, the dermis and skin quality. The layers do not all change at the same rate; which one stands out varies from person to person.

If volume loss is the main issue, meaning that fullness has decreased and contours have sunk inwards, treatments that replace the missing volume are considered.

If the main problem is that the tissue has slid downwards, meaning that the tissue has not been lost but sits lower than it should, treatments that reposition the tissue (thread lifting) are considered.

If the real issue is skin quality and the firmness of the tissue itself, the right answer is neither filler adding volume nor a thread moving tissue; which methods are considered in this situation is covered in the guide to skin-tightening treatments.

In most faces, these situations do not occur on their own but overlap. Which one is dominant in your case is shown by a consultation, not by an article.

When They Are Used Together

The two methods do not exclude each other. In expert panel recommendations, the layer-by-layer assessment is turned directly into a treatment plan: each layer is addressed separately, and different tools are used for different layers. In such a plan, a volumising treatment and a treatment that repositions tissue can be used together on the same face.

There are also studies that look directly at using the two methods together. In a small pilot study in which cross-linked hyaluronic acid filler was used together with barbed polydioxanone threads, changes in mid-face contours were followed for two years; improvements were reported both in volume measurements and in assessors’ ratings. However, this study has limits: the number of participants was small, the study was carried out at a single centre, and the authors state that larger studies are needed.

This does not lead to the conclusion that ‘both should be done’. The conclusion is this: two separate findings can be present in the same face, and in that case two separate methods can be part of the same plan. Which findings are present together in your case is shown by a consultation.

Reversal Is Not the Same for Both

One of the practical differences between the two methods is how it is possible to intervene after treatment if needed.

Hyaluronic acid is a substance that can be dissolved with an enzyme. Using an enzyme called hyaluronidase is an established way of doing this. Studies on treating complications involving blood vessels caused by hyaluronic acid filler report that giving the enzyme early markedly changes the outcomes, and that standard protocols are needed. This does not mean that filler can be fully reversed in every case; it means that there is an established way of reversing it.

Reversing a thread is a different matter. Problems reported in research in connection with threads include the thread being felt by hand or becoming visible, skin dimpling, swelling and bruising. Some of these may require the thread to be removed or corrected. This correction is done with a procedure, not with an enzyme.

This difference alone is not a reason to choose one over the other. However, it shows that the two treatments do not give the same answer to the question ‘What happens afterwards?’, and this should be discussed at a consultation.

The Limits of Both

Both methods have limits that have been clearly identified in scientific studies.

Studies on absorbable lifting threads report that, in suitable patients, the effect is seen immediately after treatment and the risk of serious complications is low. On the other hand, data on long-term effectiveness are lacking; the studies with the longest follow-up go no further than two years. In other words, what has been measured in the short term is not the same as what is known in the long term.

With filler, the limit lies in the measurement itself. There is no consensus on how the lifting effect should be defined or how it should be measured. So when assessing a claim of lift, you also need to look at how it was measured.

Both methods have side effects, but the most prominent ones are not the same. According to research on non-surgical facial treatments, the most frequently reported side effects are swelling and pain with hyaluronic acid fillers, and pain and bruising with thread lifts using absorbable threads. In an analysis that looked specifically at thread complications, swelling, bruising, the thread being visible or able to be felt by hand, and skin dimpling stand out; large differences between the reported rates are also noted.

Finally: knowing how the two methods work does not, on its own, tell you which one should be used for you. What is suitable for you is decided at a consultation.

Treatments Offered Here

The clinic offers hyaluronic acid fillers, collagen-stimulating fillers and thread lifts using dissolvable threads. Which of these may be considered is assessed at a consultation, based on which of the situations described above is dominant in your case.

Details of both treatments are on their own pages, and this guide is not a substitute for those pages: you can find how volume and contour work is done with injections on the Liquid Facelift with Collagen Stimulators page, and tissue repositioning on the French Thread Lift page. These pages also cover topics such as sessions, aftercare, who should not have the treatment, and suitability.

The aim of this guide was to clarify one distinction: is there volume that is missing, or tissue that has shifted out of place? Once you can tell these two apart, you know which question you are asking; you then find the answer together with your doctor at a consultation.