A Complete Patient Guide to Dermal Fillers

Dermal fillers are injectable medical devices used to restore volume, refine facial contours and improve skin hydration. The most widely used type is hyaluronic acid (HA) filler, a stabilised form of a substance that occurs naturally in skin and connective tissue. At The London Road Clinic, all filler treatments are carried out or directly supervised by Dr Shahe Boghossian (Medical Consultant, GMC 5204600), following a full in-person medical consultation.

This guide covers how HA filler works, which areas it is most commonly used for, what the treatment experience involves at each stage, how long results last, and how risks are identified and managed.

What are dermal fillers?

Dermal fillers are injectable substances placed beneath the skin’s surface to add volume, redefine contours or improve hydration in specific areas. Several types exist, but hyaluronic acid fillers are the most commonly used in medical aesthetic practice in the UK, and for good reason: they are effective, well-studied, and reversible.

HA is a polysaccharide that occurs naturally in the skin, joints and eyes, where it attracts and holds water in the tissue. In its natural form it is broken down rapidly. For cosmetic use, the HA is chemically stabilised through a process called cross-linking, which extends the time it lasts in the skin from hours to months. The degree of cross-linking, and the resulting viscosity of the product, is varied by manufacturers to suit different areas of the face. A softer, less viscous product is used in delicate zones such as the lips or tear troughs. A firmer, more structured product is used where lift and definition are the primary goal, such as the cheeks or jawline.

Non-HA fillers, including certain calcium hydroxylapatite and permanent filler products, also exist. These cannot be dissolved. For this reason, and given the improved dissolution capability and long-term safety profile of HA products, hyaluronic acid filler is the standard at The London Road Clinic.

How hyaluronic acid filler works

Once injected into the target tissue, HA filler adds immediate physical volume at the site of placement. The stabilised HA also begins attracting water from the surrounding tissue, contributing a subtle additional plumping effect as the product settles over the first two weeks.

Volume and structural effects are immediate and visible, though they are not fully representative of the settled result at that point. Swelling is part of the early picture. The result that reflects the treatment plan more accurately appears at around two to four weeks, once swelling has resolved and the product has distributed.

Unlike polynucleotides or Profhilo, which work by stimulating biological processes over weeks, HA filler works primarily by physical placement. The visible change is more immediate. The result is also bounded by what was injected: the product does not stimulate sustained new tissue growth, though some longer-lasting skin quality benefit from HA’s hydrating effect on surrounding tissue is observed.

Areas most often treated

Lips. One of the most requested areas. Filler is used to add volume, improve the vermilion border definition, soften vertical lip lines and address symmetry. Lip tissue has a high blood supply and metabolises filler faster than most other areas. Results typically last four to eight months.

Cheeks and mid-face. A firmer, more structured product is placed to restore or add volume to the mid-face, lift the lower face indirectly and create better facial proportion. The cheek area is less mobile than the lips, and results tend to last longer, often twelve to eighteen months.

Chin and jawline. Filler can define a recessed chin, extend the jawline, or improve the profile. Because these are structural areas rather than dynamic ones, results in this zone are among the most durable, often lasting twelve to eighteen months.

Nasolabial folds and marionette lines. The folds running from the nose to the corners of the mouth, and the lines running down from the corners of the mouth, can be softened with filler. Treatment here is typically combined with mid-face volume work rather than done in isolation, because the fold is often a downstream effect of mid-face volume loss.

Tear troughs. The hollow or shadow beneath the eye is a technically demanding area. A low-viscosity product is placed very carefully, usually via cannula, to soften the junction between the lower eyelid and the cheek. The Tyndall effect, a blue-grey discolouration that occurs when HA is placed superficially in thin skin, is a specific risk in this area and requires careful product selection and technique.

Hands. Volume loss on the dorsum of the hands makes tendons and veins more prominent. Filler placed here softens this effect and results typically last six to twelve months.

What happens at the consultation

No filler treatment at The London Road Clinic proceeds without a full in-person consultation first. This is not administrative; it directly shapes the treatment plan.

At consultation, a full medical history is taken, covering current medications (including blood thinners, which increase bruising risk), any previous filler or aesthetic treatments, allergies and any history of cold sores (which can be reactivated by injectable treatment in the lip area). Photographs are taken in standardised lighting and angle so that the pre-treatment baseline is documented.

Facial structure and anatomy are assessed, including existing proportions, symmetry, skin quality and the likely position of underlying anatomy. The plan is then discussed, including the amount of product, the area of focus, the expected result at settling and the realistic range of outcome.

You will be asked to give informed consent before any treatment proceeds. This includes a discussion of risks. If a plan cannot be agreed, or if a concern arises during assessment that makes treatment inadvisable, treatment will not take place.

What happens during treatment

Topical anaesthetic cream is applied to the treatment area and left for around twenty minutes. Many filler products also contain lidocaine in the formulation itself, which contributes to comfort during injection.

Filler is placed using either a fine needle or a blunt-tipped cannula, depending on the area and the clinical judgment about which technique carries the lower risk for that specific location. A cannula, because of its blunt tip, is less likely to penetrate a blood vessel directly, and is used in higher-risk areas for this reason.

The practitioner assesses symmetry and proportion throughout the session and will make adjustments as treatment progresses. Once complete, ice or cooling is applied to the area to reduce swelling.

Most sessions take twenty to forty-five minutes, depending on the area and volume being treated.

The settling period: what to expect afterwards

The first two to three days after filler are not representative of the final result. Swelling is normal, particularly in the lips, where it can be significant in the first 24 to 48 hours. Bruising occurs in a proportion of patients, more commonly in those taking aspirin, ibuprofen or fish oil supplements, and those with naturally thinner skin. Mild tenderness at the injection sites is expected.

Over the first two weeks, swelling resolves, any bruising fades and the product settles into the tissue. The result becomes clearer as this happens. Most clinicians assess the result at two to four weeks rather than immediately after treatment, because the settled picture is more informative.

Aftercare in the first 24 hours: avoid strenuous exercise, saunas, sunbeds and alcohol. Do not apply heavy pressure to the treated area. Sleep with your head slightly elevated if swelling is significant. If you notice any blanching of the skin (a white or pale patch), severe or unusual pain, or a mottled skin pattern, contact the clinic immediately. These can be early signs of vascular compromise and require prompt management. For more on what these signs mean and why they matter, see our guide to vascular occlusion and filler safety.

How long does dermal filler last?

Duration depends on the area treated, the product used, the volume placed and your individual rate of metabolism. These are reasonable estimates for most patients:

Filler does not disappear at the end of this period as if a switch has been flipped. It metabolises gradually. Most patients notice their result softening before they notice it gone. Many choose to maintain with a smaller top-up volume at this stage rather than returning to a full course.

Risks and how they are managed

The most common effects after filler are bruising and swelling, which are expected rather than complications. Both resolve without treatment. Arnica (topical or oral) can help with bruising; time and ice help with swelling.

Beyond these, the risks worth understanding include:

Tyndall effect. A blue-grey discolouration that appears when HA is placed too superficially in thin-skinned areas, most commonly under the eye. It is treated by dissolving the superficially placed product with hyaluronidase and, if appropriate, re-treating with a more appropriate product at the correct depth.

Nodules or lumps. An uncommon effect, usually caused by placement technique or product choice in a high-movement area. Most resolve over time. Hyaluronidase can dissolve persistent HA nodules.

Delayed inflammatory reaction. A rare response, sometimes triggered by a systemic event such as illness or dental procedures months after treatment, in which the body mounts a localised inflammatory response around the filler. Treated with a combination of anti-inflammatory medication and hyaluronidase.

Infection. Rare with sterile technique. Clinics with appropriate infection-control protocols reduce this risk significantly.

Vascular occlusion. The most serious potential complication of filler treatment. It occurs when filler blocks or compresses a blood vessel, cutting off blood supply to surrounding tissue. Recognised early, it is managed with hyaluronidase and appropriate emergency protocols. Clinics that do not hold hyaluronidase on-site cannot respond adequately. A full explanation of this complication and the safety questions worth asking before any filler appointment is in our dedicated guide to vascular occlusion.

Because all of the fillers used at The London Road Clinic are hyaluronic acid-based, all complications related to product placement can be addressed with hyaluronidase, which we hold on-site at every filler session.

Who is and isn’t suitable

Filler treatment is appropriate for most healthy adults who want to address volume loss, contour concerns or specific facial features after a consultation confirms suitability.

Treatment is not appropriate during pregnancy or breastfeeding. Active skin infection in the proposed treatment area requires the treatment to be postponed. A history of severe allergy or anaphylaxis requires careful review. Certain autoimmune conditions, blood disorders and anticoagulant medications require specific assessment.

Under UK age-restriction legislation introduced in October 2021, cosmetic dermal filler treatments cannot be offered to anyone under 18.

Frequently asked questions