Dermal Filler Side Effects: Risks, Aftercare & Warning Signs

Dermal fillers are gel‑like substances injected under the skin to soften lines, restore volume and enhance features. Most are temporary and break down naturally over time. As with any medical treatment, side effects can occur: many are mild and short‑lived, but uncommon reactions and rare emergencies are possible, particularly if filler enters a blood vessel.

This article explains what’s normal after fillers and what isn’t. You’ll learn how side effects happen, typical timelines, and red‑flag symptoms that need urgent help. We compare risks by filler type and treatment area, who should avoid or delay treatment, medicines that increase risk, and the practical aftercare that reduces problems. We also cover options for reversing fillers and the UK safety rules and reporting routes—so you can make informed choices and know exactly when to act.

What dermal fillers are and how side effects happen

Dermal fillers are injectable gels placed beneath the skin to smooth wrinkles or restore volume. Because a needle enters living tissue and a material is added, the body can react in several ways. Short‑lived redness, swelling and bruising are usually from injection trauma. Less commonly, the immune system may form nodules or granulomas, or bacteria introduced at injection can cause infection. The most serious events occur if filler enters a blood vessel, blocking blood flow and risking skin necrosis, stroke or even blindness; these complications are rare but can be permanent.

• Mechanical trauma: Needle entry causes temporary swelling and bruising.

• Inflammatory/immune response: Allergic reactions, nodules or granulomas.

• Infection: Local cellulitis, rarely abscess.

• Placement issues: Lumps, asymmetry or migration.

• Vascular occlusion: Accidental injection into a vessel leading to tissue damage or vision problems.

Common short-term side effects (what’s normal and how long it lasts)

Right after treatment, most people notice mild, local reactions from the injections. These common dermal filler side effects are expected and reflect normal tissue response to needle entry and the product. They tend to appear immediately or within hours and usually settle on their own within a few days to about two weeks.

• Redness and swelling: Typically mild and short‑lived; often improves within a few days and may take up to 1–2 weeks to fully resolve.

• Bruising: Variable; can last several days and sometimes up to two weeks depending on the area and your tendency to bruise.

• Tenderness or soreness: Usually mild and improves over several days as injection sites heal.

• Itching or mild rash: Local and transient; should ease within days.

• Back‑of‑hand treatments: May cause temporary difficulty with activities (hand indication only), which resolves as swelling subsides.

If symptoms persist beyond two weeks, worsen, or are accompanied by increasing pain, heat, or fever, contact your practitioner promptly.

Less common side effects that need attention

Most dermal filler side effects are short‑lived, but some less common reactions warrant a timely check‑in with your practitioner. These aren’t usually emergencies, yet leaving them to “settle” can let problems smoulder. Act early if you notice any of the following after the first few days, or if they develop weeks later.

• Prolonged or worsening inflammation: Redness or swelling lasting beyond 1–2 weeks, or flare‑ups after illness, vaccination or dental work.

• Lumps or nodules/granulomas: Firm or tender bumps that persist and may need medical treatment.

• Infection signs: Increasing pain, heat, redness, fever, pus, open or draining wounds.

• Allergic reactions: Rash, itching or swelling; higher risk with animal‑derived products.

• Product migration or asymmetry: Filler movement or unevenness that doesn’t improve as swelling resolves.

• Leakage from injection sites: Oozing of product.

• Sensory or skin changes: Numbness, pimples that resemble acne.

Sudden skin colour changes, severe escalating pain or vision symptoms require urgent assessment (see next section).

Serious complications to know about (vascular occlusion, blindness, stroke)

The most serious dermal filler side effects happen when product is inadvertently injected into, or compresses, a blood vessel. This “vascular occlusion” can cut off circulation and lead to skin necrosis (tissue death) and, if vessels supplying the eye or brain are affected, rare but devastating complications such as blindness or stroke. While uncommon, the FDA stresses that these outcomes can be severe and permanent, so rapid recognition and action are critical.

If you experience any of the following during or after treatment, treat it as an emergency and seek urgent medical help:

• Sudden severe pain at or near the injection site, especially if it escalates rather than eases.

• Skin colour changes: blanching (paleness), a dusky/mottled appearance, or cool, numb skin.

• Vision symptoms: sudden blurred or lost vision, seeing shadows/curtains, eye pain or headache.

• Stroke‑like symptoms: facial droop, difficulty speaking, or weakness/pain on one side of the body.

What to do now: stop any further injections, contact your practitioner immediately, and go straight to urgent care/A&E (in the UK, call 999 for severe vision or stroke‑like symptoms). Early assessment offers the best chance to limit tissue damage and protect sight or neurological function.

Delayed and long-term complications (weeks to years later)

Not all dermal filler side effects appear straight away. The FDA notes that reactions can emerge weeks, months, or even years later, and may flare after illnesses, vaccinations or dental procedures. These delayed issues are less common, but acting early prevents them becoming entrenched.

• Delayed inflammation: Recurrent redness or swelling near injection sites, sometimes triggered by infection, vaccination or dental work.

• Nodules/granulomas: Firm bumps from a foreign‑body response; may need injections, oral antibiotics or surgical removal.

• Chronic or late infection: Increasing pain, heat, pus or a non‑healing wound weeks after treatment.

• Product migration/asymmetry: New unevenness as filler shifts over time.

• Scarring changes: Hypertrophic scarring or visible surface vessels (telangiectasia).

• Cold sore reactivation: Recurrent herpes labialis is reported after lip augmentation.

If you develop any of the above—especially if symptoms persist or worsen—contact your practitioner promptly for assessment and treatment.

Risk by filler type (HA, CaHA, PLLA, PMMA and fat grafting)

Not all dermal fillers carry the same risk profile. Temporary HA and CaHA generally cause short‑lived reactions and break down within about a year; semipermanent PLLA lasts longer; PMMA is permanent. Long‑acting fillers show higher rates of complications (e.g., infection, nodules), and some materials are difficult or impossible to remove. Fat grafting uses your own fat, is long‑lasting, but involves liposuction and downtime. Knowing how type influences dermal filler side effects helps you choose wisely.

• HA (hyaluronic acid): Temporary (around 6–12 months); usually mild, short‑term reactions; degradable.

• CaHA: Suited to deeper folds; lasts about 1 year; similar injection‑related risks.

• PLLA: Stimulates collagen; lasts two years or more; delayed inflammation or nodules can occur.

• PMMA: Permanent (results up to ~5 years); higher complication rates; bovine collagen warrants allergy checks; hard to remove.

• Fat grafting: Long‑lasting autologous fat; adds surgical risks and about 1–2 weeks’ recovery after liposuction.

Higher-risk areas of the face and why technique matters

Some parts of the face are riskier because they contain dense, important blood vessels—including vessels that communicate with the eyes. In these zones, a misplaced bolus or high‑pressure injection can compress or enter a vessel, increasing the chance of vascular occlusion, skin damage and, rarely, vision problems. Careful patient selection, product choice and meticulous technique by an experienced, licensed injector reduce dermal filler side effects and serious complications.

• Around the eyes (periocular/tear trough and brow area): Closest to vessels linked with the eyes; blindness has been reported when filler blocks arterial flow.

• Upper face (forehead/brow region): Rich vascular networks demand precise depth and placement.

• Lips: Highly vascular, so more bruising and swelling; cold sores can reactivate after lip augmentation.

• Areas with previous fillers, scars or inflammation: Higher likelihood of prolonged swelling or nodules.

How technique lowers risk:

• Qualified injector and approved products: Use licensed clinicians with FDA‑approved fillers; avoid needle‑free “pens”.

• Low volume, slow, controlled injections: Favour small aliquots and gentle pressure to maintain control.

• Correct plane and sterile practice: Accurate depth minimises intravascular or superficial placement; clean technique reduces infection.

• Stop at warning signs: Escalating pain or colour change requires immediate reassessment and action.

Who should avoid or delay dermal fillers

Fillers are elective medical treatments, and there are times when it’s safer to wait—or not have them at all. If any of the situations below apply, discuss with a qualified practitioner and consider postponing treatment to reduce dermal filler side effects and complications.

• Under 22 years: FDA approvals for dermal fillers are for adults 22+; safety in younger patients isn’t established.

• Pregnant or breastfeeding: Elective injectables are not recommended; defer until after.

• Active skin problems at the site: Rash, active acne, hives or infection—treat first.

• Bleeding disorders: Higher risk of bruising/bleeding; seek specialist advice.

• Severe allergies to filler components: Especially animal‑derived collagen; allergy testing may be needed.

• Prone to keloids/hypertrophic scars: Increased risk of problematic scarring.

• Unwell, recently vaccinated or having dental work: These can trigger inflammatory flares—separate timing.

• History of cold sores (lip treatments): Avoid during an outbreak; ask about antiviral prophylaxis.

• Seeking body contouring (breasts/buttocks): Fillers are not approved for large‑scale body enhancement—avoid.

Medicines and health factors that increase your risk

Certain medicines and medical factors can raise the likelihood or severity of dermal filler side effects, especially bruising, prolonged swelling, infection and inflammatory flares. Always tell your practitioner about every prescription, over‑the‑counter medicine and supplement you take, plus recent illnesses, vaccinations or dental work, before you book.

• Blood thinners: Prescription anticoagulants/antiplatelets and some OTC pain relievers that affect clotting increase bruising and bleeding.

• Supplements affecting clotting: Some herbal/vitamin products can thin the blood and worsen bruising.

• Recent illness, vaccination or dental work: Can trigger inflammation or swelling at previous filler sites.

• Active skin issues at the site: Rash, acne, hives or infection heighten infection/inflammation risk.

• Bleeding disorders: Increase bleeding/bruising complications.

• Severe allergies to filler components: Especially animal‑derived collagen; allergy testing may be required.

• Prone to keloids or hypertrophic scars: Higher risk of problematic scarring.

• Cold sores history (lip treatments): Lip augmentation can reactivate herpes labialis; discuss antiviral prophylaxis.

Before your appointment: safety checklist for choosing a provider

The single biggest way to limit dermal filler side effects is to choose the right clinician and setting. Look for a licensed, experienced injector using approved, prescription‑only products in a proper medical environment. Ask clear questions about products, technique and emergency plans before you book.

• Verify credentials: Licensed clinician with specific training in dermatology/plastic surgery injectables.

• Medical setting only: Not at home, parties or mall kiosks; clean, clinical standards.

• Approved products: Properly labelled, sealed vials or pre‑filled syringes; prescription‑only.

• No DIY or pens: Never buy fillers online or use needle‑free “pens”.

• Informed consent: Review patient information, treatment areas, benefits, risks and alternatives.

• Full medical history: Disclose medicines, supplements, allergies, bleeding disorders, illness, vaccines and dental work.

• Complication protocol: Ask how they manage infection, inflammation and rare vascular/vision events, and same‑day contact routes.

• Aftercare and follow‑up: Clear written instructions and easy access for reviews/concerns.

• Safety red flags: Avoid anyone offering body contouring (breasts/buttocks) or treating under‑22s with fillers.

Aftercare: what to do in the first 48–72 hours

The first three days are about calming swelling and bruising, protecting skin, and spotting anything that isn’t normal. Follow the plan your clinician gives you for the specific product and area treated; good early care reduces common dermal filler side effects and helps results settle smoothly.

• Cool the area: Apply a clean, wrapped ice pack intermittently on day one to ease swelling and discomfort.

• Hands off: Don’t press or massage the sites unless your practitioner specifically tells you to.

• Avoid heat extremes: Steer clear of saunas, steam rooms, very hot showers and intense sun exposure while swelling settles.

• Ease back on exercise: Skip vigorous workouts for 24–48 hours; your clinician may advise a brief pause to limit swelling and bruising.

• Medications: If needed, over‑the‑counter antihistamines or anti‑inflammatories can help reduce itch/redness—check with your practitioner first.

• Lips and cold sores: If you’re prone to herpes labialis and had lip injections, follow any antiviral plan your clinician provided.

• Monitor symptoms: Worsening pain, heat, spreading redness, pus or fever can signal infection—contact your practitioner promptly; seek urgent help for severe pain, skin colour changes or any vision symptoms.

What not to do after fillers (dos and don’ts)

Good results depend on what you avoid in the first few days. The aim is to limit swelling and bruising, prevent irritation and reduce the chance of delayed inflammatory flares. Use this quick checklist to steer clear of the most common pitfalls linked to dermal filler side effects.

• Don’t massage or press the area unless your clinician tells you to — it can move product or worsen irritation.

• Don’t expose the skin to extremes of heat or cold (saunas, steam rooms, very hot showers, skiing in harsh cold) while swelling settles.

• Don’t do strenuous exercise for 24–48 hours; your provider may advise a short pause to limit bruising and swelling.

• Don’t book vaccines, dental work or elective procedures right away; these can trigger inflammation at filler sites — separate the timing.

• Don’t try to “fix” anything yourself — never buy fillers online or use needle‑free pens; only licensed clinicians should inject.

• Don’t ignore red flags; severe pain, colour change, vision issues or stroke‑like symptoms need urgent help.

• Do keep the area clean and cool as advised.

• Do contact your practitioner early if anything feels off rather than waiting it out.

Managing common side effects at home

Mild swelling, redness, bruising, tenderness and slight itch are the most common dermal filler side effects and usually improve within a few days, settling by 7–14 days. Simple measures help you feel more comfortable while things calm down; avoid DIY “fixes” or massaging product unless your practitioner has told you to.

• Cool compresses: Apply a clean, wrapped ice pack intermittently on day one to ease swelling and soreness.

• Hands off: Keep the area clean; don’t press, pick or massage unless specifically advised.

• Bruising: Expect it to fade over several days (sometimes up to two weeks); continue gentle cooling in the first 24 hours.

• Itch or redness: An over‑the‑counter antihistamine or anti‑inflammatory may help if your practitioner says it’s suitable for you.

• Lips/cold sores: If you’re prone to herpes labialis and had lip injections, follow any prescribed antiviral plan promptly.

If symptoms are getting worse rather than better, or haven’t settled by two weeks, contact your practitioner for review.

Red-flag symptoms: when to call your practitioner or seek urgent help

Serious dermal filler side effects are uncommon, but delay makes harm more likely. If something feels wrong, act fast. Use this guide to decide whether to contact your practitioner the same day or go straight to urgent care/A&E. Rapid assessment can prevent skin necrosis, protect vision and reduce the risk of stroke‑like complications.

• Call your practitioner urgently (same day) if you have:

  • Worsening pain, heat or swelling after the first 24–48 hours.

  • Spreading redness, fever, pus or an open/draining wound (possible infection).

  • New, persistent lumps or nodules that are tender or inflamed.

  • Product leakage from an injection site.

• Go to A&E or call 999 now if you develop:

  • Sudden, severe or escalating pain at or near the injection area.

  • Skin colour changes: blanching (pale/white), dusky/mottled patches, or skin that feels cold or numb.

  • Any vision change: blurred or lost vision, double vision, eye pain, or a sudden severe headache.

  • Stroke‑like symptoms: facial droop, slurred speech, or weakness/pain on one side of the body.

  • Signs of a severe allergy: widespread hives, swelling of lips/tongue, difficulty breathing.

When in doubt, treat symptoms as urgent and seek medical help immediately—then inform your practitioner.

Removing or reversing fillers: options and limits

What can be done depends on the filler type, where it was placed and whether you’re correcting a look or treating a complication. Temporary fillers often soften as your body breaks them down, so time is part of the plan. When true complications occur, management aims to reduce inflammation, treat infection and protect tissue—remember that some products are difficult or impossible to remove, and any corrective procedure carries its own risks.

• Temporary fillers (HA, CaHA): Typically diminish over 6–12 months; minor asymmetry may settle as swelling resolves or with planned touch‑ups.

• Collagen stimulators (PLLA): Longer‑lasting; firm bumps (nodules/granulomas) may need injections, oral antibiotics or surgical removal.

• Permanent fillers (PMMA): Not absorbed; higher complication rates and often require surgical correction; full removal may not be possible.

• Fat grafting: Long‑lasting; adjustments generally require further procedures rather than simple “dissolving”.

Discuss realistic outcomes with your practitioner before treatment so you understand what can—and cannot—be reversed if dermal filler side effects arise.

Dermal fillers and botulinum toxin: combined treatments and safety

Fillers add or restore volume; botulinum toxin (e.g., Botox, Dysport, Xeomin, Jeuveau) relaxes muscles so lines show less. Used together, they can complement results, but the FDA notes the safe use of dermal fillers in combination with botulinum toxin has not been evaluated in clinical studies. If you choose both, your clinician may stage treatments so swelling doesn’t mask outcomes and to minimise dermal filler side effects.

• Know different risks: Botulinum toxin side effects include facial weakness, eyelid or brow drooping; less commonly pain, swelling, redness or bruising; rarely double vision, dry eyes, or difficulty swallowing/breathing.

• Don’t mix DIY: Only receive prescription products from a licensed healthcare professional in a medical setting.

• Not for pregnancy/lactation: Cosmetic botulinum toxin isn’t recommended if you’re pregnant or breastfeeding.

• Report problems promptly: Any red‑flag symptoms need urgent assessment.

UK safety and regulation: licensed products and reporting problems

In the UK, treat dermal fillers as a medical procedure: insist on licensed clinicians, approved products and a clinical setting. Regulators warn against needle‑free “pens”, DIY or buying fillers online, and against using injectable fillers for large‑scale body contouring. Protect yourself by checking the basics before anyone injects.

• Prescription‑only, sealed product: Pre‑filled syringes/vials must be properly labelled and unopened.

• Qualified injector, medical environment: No home visits, parties or kiosks.

• Patient information provided: Ask for the product’s patient leaflet and keep it.

• Record the details: Note the product name, batch/lot number and treatment areas.

• Clear consent and plan: Risks, benefits, alternatives and complication protocol explained.

If you experience a problem, contact your practitioner promptly; for urgent symptoms, seek immediate medical care. You can also submit a consumer safety report through the national adverse event reporting scheme and keep copies of all documentation to support follow‑up.

Key takeaways

Most dermal filler reactions are mild and settle within 7–14 days, but less common infections or inflammatory flares can occur, and rare vascular events can threaten skin, sight or brain. Choose a licensed injector, insist on approved products, time treatments around illness/vaccinations, follow aftercare carefully, and know the red flags so you can act fast.

• What’s normal: Redness, swelling, bruising, tenderness; usually settles within 1–2 weeks.

• When to check in: Persistent inflammation, lumps/nodules, asymmetry or signs of infection.

• Emergency signs: Severe pain, skin blanching/mottling, vision change, stroke‑like symptoms.

• Filler type matters: Long‑acting/permanent fillers carry higher, harder‑to‑fix complication risks.

• Safety basics: Licensed injector, approved products, medical setting; avoid DIY/needle‑free pens.

• Be transparent: Share medicines/supplements and health history; delay if pregnant/breastfeeding or unwell.

For personal advice and safe, clinician‑led treatment in Luton, book a consultation with Wigmore Smiles & Aesthetics.