Hyaluronic acid (HA) fillers are among the most common facial injections, used to restore volume in the cheeks and temples, shape the chin and lips, and soften folds around the nose and mouth. Before deciding, most people want three answers: what side effects to expect, how long it lasts, and whether it can be undone if they are unhappy. This guide covers all three, including the rare complication that deserves the most respect, vascular occlusion. It draws on our dermal filler page and published medical literature. Your own plan is confirmed at consultation.
What are the common side effects of dermal fillers?
The most common effects are temporary redness, swelling, tenderness and bruising at the injection sites, which usually settle over several days, with occasional bruising lasting a little longer. Lips and under-eyes tend to swell more. These are normal injection reactions, and most people return to their usual routine quickly, following the aftercare notes they are given.
In more detail:
- Swelling is most noticeable in the lips, which can look bigger than planned for the first few days before settling. Judge the shape after the swelling has gone.
- Bruising is more likely in areas with more blood vessels. Our treatment page notes that micro-cannulas are used where appropriate to help reduce it.
- Tenderness and slight unevenness: early on the area can feel firm or a little lumpy, and this usually improves as swelling settles. Do not massage it hard yourself; your physician decides whether massage is needed.
- Injection marks heal quickly. Our aftercare notes suggest no makeup for 24 to 48 hours.
What less common problems should I watch for?
- Small lumps or nodules, from uneven product placement or a local tissue reaction. Some settle on their own; some need treatment, which can include dissolving.
- Asymmetry or overfilling, usually linked to dose, depth or existing differences between the two sides, and adjustable at review.
- The Tyndall effect: HA placed too superficially, especially under the eyes, can show a faint blue tint through the skin.
- Infection or delayed inflammatory reactions: uncommon, and may appear weeks or longer later as redness, swelling, firmness or pain. These need a physician's assessment.
- Allergic reactions: people allergic to hyaluronic acid or lidocaine should not have filler.
If a lump persists, grows, or comes with redness, warmth or pain, contact the clinic rather than treating it yourself.
What is vascular occlusion, and which warning signs need urgent help?
Vascular occlusion is a rare but serious complication of HA filler: product enters or compresses a blood vessel and blocks blood flow, which can damage the overlying skin and, very rarely, affect vision. The medical literature, such as DeLorenzi's 2014 review of vascular complications in Aesthetic Surgery Journal, treats it as a key risk every injector must plan for. Severe pain, skin that turns white, dusky or mottled, or blurred or changed vision after treatment means you should contact the clinic or go to emergency immediately.
These signs can appear during treatment or after you have left the clinic. Do not wait to see whether it improves; time matters for the outcome.
Steps that lower the risk include knowing the facial vascular anatomy, choosing the right depth and tool (such as a cannula) in higher-risk areas, injecting small amounts slowly, watching skin colour throughout, and having hyaluronidase and an emergency protocol on hand. None of this removes the risk entirely, but it means a problem is recognized and treated early.
The nose, the area between the brows, the upper part of the nasolabial fold and the temples are generally regarded as higher-risk zones. Your physician takes extra care there and may advise against treating them or suggest another approach.
How long do dermal fillers last?
Our treatment page notes that results typically last 9 to 18 months, depending on the product and the area treated. Areas that move a lot, such as the lips, tend to break filler down faster, while deeper, less mobile areas such as the cheeks and chin often hold longer. Metabolism, lifestyle and the amount used also play a part, so individual results vary.
Your body gradually absorbs HA, so the effect fades slowly rather than disappearing overnight. It is usually wiser to discuss a top-up once the effect has softened than to keep adding while the area is still full, which is how faces drift towards looking overdone.
Can hyaluronic acid filler be dissolved?
Yes. HA filler can be broken down with an enzyme called hyaluronidase. It is used in two situations: urgently, in adequate amounts, for vascular occlusion; and electively, to correct asymmetry, overfilling, lumps or the Tyndall effect. Your physician decides whether and how much to use.
Worth knowing:
- It only works on HA fillers. It has no effect on other types, such as collagen-stimulating fillers, so tell your physician everything you have had before.
- It may take more than one session, and it can also break down some of your skin's own hyaluronic acid, so the area may look a little hollower than expected for a while before recovering.
- Hyaluronidase itself can cause allergic reactions, so your physician will ask about allergies.
- After dissolving, it is usually advised to let the tissue settle for a while before considering new filler.
Being reversible is a genuine safety advantage of HA filler, but it is not a reason to treat casually and dissolve later.
What should I do after filler treatment?
Our aftercare notes:
- Do not touch, press or massage the area for 24 hours.
- Skip saunas, hot baths and strenuous exercise for 48 hours.
- Avoid makeup for 24 to 48 hours.
- Gentle cooling can help with swelling.
- Contact your physician about persistent pain or lumps.
Also avoid dental procedures for 2 weeks before and after treatment.
Who should not have dermal fillers?
Fillers are not suitable, or need a physician's assessment first, during pregnancy or breastfeeding, with active infection or inflammation at the site, with an allergy to hyaluronic acid or lidocaine, after recent facial surgery or filler, or with autoimmune or bleeding disorders.
One more situation to think through: if the main concern is marked skin laxity and sagging, filler alone often ends up heavy and unnatural. Your physician will say so plainly and may suggest a different or combined approach.
How should I prepare for my filler appointment?
- Our pre-care notes: avoid alcohol and medications that increase bruising, such as aspirin, for 48 hours beforehand. Your physician decides whether any medication should change; do not stop one on your own.
- Do not book dental work within 2 weeks before or after.
- Tell your physician about every filler you have had: when, where, and what type if you know. Mention it especially if you are not sure what was used.
- List your medications, supplements and allergies.
- Write down your questions: is this a higher-risk area, needle or cannula, how do I reach the clinic if something feels wrong, and is hyaluronidase kept on site?
How does RAAC approach dermal fillers?
At RAAC, a medical team led by Dr. Charles Jiang, a licensed physician in British Columbia, starts with a proportion-based facial assessment to decide whether the concern is volume loss, missing structure or laxity, and then whether filler suits you, which type and at what depth. Cannulas are used where appropriate, and the aim is balance rather than overfilling. Pricing depends on the product and areas and is explained after consultation. Consultations are available in English, Mandarin and Cantonese.
The clinic is on No. 3 Road in Richmond, BC, a short walk from Lansdowne Station on the Canada Line.
Frequently asked questions
I can feel a small lump. Is that normal? Slight firmness or unevenness early on is common and usually improves as swelling settles. If it persists, grows, or becomes red, warm or painful, contact the clinic.
Will filler stretch my skin over time? With sensible amounts and intervals, it generally does not. Problems tend to come from stacking more filler on top in a short time. Reassessing once the effect has softened is the safer rhythm.
Can I have radiofrequency or ultrasound treatments after filler? Usually yes, but tell your physician where and when you had filler so the order and spacing can be planned.
Further reading
- A guide to lip filler
- The science behind subtle facial fillers
- Dermal fillers and collagen biostimulation
This article is for educational purposes only and does not constitute medical advice. Please consult with a qualified healthcare professional before undergoing any treatment.
