What Are Dermal Fillers? Types, Uses, Risks and What to Ask Your Doctor

What are dermal fillers

Dermal fillers are injectable medical devices used to make the face look smoother or fuller. [1] The US FDA also calls them soft tissue fillers or wrinkle fillers. [1] The Thai FDA (อย.) describes them as injectable products that fill in or soften wrinkles and deep folds on the face. [3]

The Thai FDA classes fillers as medical devices, and the maker, importer and seller must get permission before selling them. [3] The US FDA says having filler injected should be considered a medical procedure, not a cosmetic treatment. [1]

Fillers are not the same as botox or skin boosters. For the comparison, read [[botox-vs-filler]] and [[skin-booster-vs-filler]].

Types of dermal filler, and which is used most

The FDA lists absorbable materials such as hyaluronic acid and a permanent material, and hyaluronic acid is the most used worldwide. [2][6] Hyaluronic acid (HA) is a sugar found in body tissue. As a gel it combines with water and swells, which gives the filling effect. [2] The HA in fillers can come from bacteria or rooster combs, and some is chemically cross-linked so it lasts longer in the body. [2]

The FDA also names calcium hydroxylapatite (CaHA), a mineral found in teeth and bones, and poly-L-lactic acid (PLLA), a biodegradable polymer. [2] The permanent type is PMMA, and the FDA has approved only one product made from a material that stays in the body. [2] Permanent fillers are approved only for nasolabial folds and cheek acne scars. [1]

The table follows the FDA pages. The durations are rough figures for the material, and the FDA says how long an effect lasts depends on both the material and the area injected. [1][2] Some fillers also contain lidocaine to reduce pain during injection. [2] To read the HA wording on a label, see [[hyaluronic-acid-label]].

Where dermal fillers can be injected

The US FDA has approved absorbable fillers for facial wrinkles and folds, the lips, cheeks, chin and back of the hand, depending on the product. [1] These approvals are for adults aged 22 or older. [1]

Absorbable fillers are approved for moderate to severe wrinkles and folds, such as the nasolabial folds and the fine lines around the mouth. [1] Adding volume to the lips, cheeks, chin and back of the hand is a separate group of approved uses. [1]

The FDA says it has not approved filler use between the eyebrows, in the nose, around the eyes, in the forehead or in the neck, and it recommends against these uses. [1] For under-eye filler, read [[under-eye-filler-questions]].

The Thai FDA says each filler suits different areas, and the details are on the label and the device leaflet written for professionals. [3] The US FDA also says different products are approved for different areas, and some locations have not been reviewed. [1] So whether a spot is covered depends on the label of that exact product, not on the name of the area. [1][3]

Each area has its own article: [[lip-filler]], [[chin-temple-nose-filler]] and [[nasolabial-cheek-filler]].

Can dermal fillers be dissolved

Hyaluronic acid fillers can be dissolved with the enzyme hyaluronidase, but permanent fillers are hard or impossible to remove. [1][5] The FDA says that removing or reducing filler because of side effects may need injections, surgery or other procedures, which carry their own risks. [1]

A clinical guideline explains that hyaluronidase breaks down the structure of HA and can dissolve cross-linked HA filler. [5] Doctors use it when filler enters a blood vessel, when a nodule appears weeks or months after injection, or when the result is poor, for example from too much filler or movement of the filler. [5]

The same guideline says that in the United Kingdom and the United States, using hyaluronidase to dissolve filler is an off-license use, and patients should be told this when they give consent. [5] The authors also discuss worries about allergy to an enzyme that comes from animals. [5]

This article did not check the Thai registration of hyaluronidase products. Ask the doctor which product is used and check the current status with อย.

What are the risks of dermal fillers

Bruising, swelling, redness and pain are the common ones, and the most serious risk is filler entering a blood vessel. [1] Most side effects, such as swelling and bruising, start soon after injection, and many clear in a few days to weeks. [1] In some cases a side effect appears weeks, months or even years later. [1]

Less common problems are nodules or granulomas, infection, open wounds, allergic reaction and tissue death. [1] Rare events reported to the FDA are severe allergic reaction, filler moving away from the site, leaking or rupture of the filler, permanent hard nodules and death. [1]

When filler enters a blood vessel, the vessel can block and tissue loses its blood supply. The FDA says the chance is low, but the result can be serious and permanent, including tissue death, vision problems up to blindness, and stroke. [1] The Thai FDA warns of the same blocked vessels, tissue death and blindness. [3]

A 2019 systematic review found 190 cases of blindness from fillers. Of these, 90 (47%) involved the patient's own fat injected as filler and 53 (28%) involved HA. [6] The authors concluded that the patient's own fat was the most common cause even though HA is the most used filler worldwide. [6] These numbers come from case reports, not from rates, so they cannot say how often it happens. [6]

An international expert panel that reviewed HA fillers concluded that most adverse reactions are mild and transient and that serious events are rare. [4] They state that knowing facial anatomy, choosing patients and products well, and using sound technique reduce the risk. [4]

Which symptoms after filler need urgent medical care

The FDA says to get medical help at once for unusual pain, vision changes, white, gray or blue skin near the injection, or signs of a stroke. [1] These can happen during the injection or soon after it. [1]

The FDA tells injectors to stop injecting immediately if they see signs of a blood vessel injection, such as blanched skin, a change in vision or unusual pain, and to have a treatment plan ready beforehand. [1] The FDA gives these examples of stroke signs.

• Sudden difficulty speaking [1]
• Numbness or weakness in the face, arms or legs [1]
• Difficulty walking [1]
• Changes in vision [1]
• A drooping face [1]
• Severe headache, dizziness or confusion [1]

Who should inject dermal fillers, and what to check first

The FDA advises a licensed provider trained in filler injection, and the Thai FDA advises a clinic with a dermatology doctor and a label check. [1][3] The FDA says not to inject filler yourself and not to buy filler online, because it could be counterfeit or unapproved. [1]

The Thai FDA advises asking to check the label to see whether the product is authorised, by its registration number, on the อย. website or by QR code, and photographing the product before the procedure. [3]

The FDA also says to discuss the injection sites and the risks at each site, and to read the patient labeling of the exact filler. [1] It says the provider should have a plan in case filler enters a blood vessel. [1] Here are questions to take to the doctor.

• What is the product called, and what is its อย. registration number?
• Is the area to be injected on the product label, or is it off-label?
• What are the risks specific to that area?
• If filler enters a blood vessel, what is the clinic's plan? [1]
• If I want it removed, how is that done, and what are the risks?

Who should wait or tell the doctor before filler

The FDA says to tell the doctor about skin inflammation or infection, a bleeding disorder or allergies, and says safety is unknown in pregnancy, breastfeeding and under age 22. [1] With active pimples, cysts, rashes, hives or an infection, the FDA says filler should be delayed until that is managed. [1]

Allergies to mention are collagen or eggs, animal products, the local anaesthetic lidocaine and bacteria, because some fillers contain these. [1]

The FDA adds that safety is unknown for people prone to keloids or excessive scarring. [1] Use together with botox or other treatments has not been evaluated in a controlled study, and neither has repeated long-term use. [1] For botox and filler, read [[botox-vs-filler]].

What to read next about fillers

The filler series covers each area, the brands and aftercare in separate articles, and each one uses official sources and research like this one.

• Lips: [[lip-filler]]
• Brands such as Restylane, Juvederm, Neuramis and EPTQ: [[filler-brands-compared]]
• Chin, temple and nose: [[chin-temple-nose-filler]]
• Nasolabial folds and cheeks: [[nasolabial-cheek-filler]]
• Aftercare, lumps and how long it lasts: [[filler-aftercare-lumps-duration]]
• Botox versus filler: [[botox-vs-filler]]
• Under the eyes: [[under-eye-filler-questions]]
• Skin boosters versus filler: [[skin-booster-vs-filler]]