What Are the Risks of Dermal Filler?
Every injection carries some risk. The common, minor ones are bruising, swelling, and temporary lumps or asymmetry while everything settles. The rarer but serious risk is vascular occlusion, where filler is accidentally injected into or compresses a blood vessel, which can affect skin or, in the most serious cases involving the areas around the nose and glabella, vision. This is why injector training and anatomy knowledge matter more than almost anything else in this field. I trained extensively in facial anatomy, and I always keep hyaluronidase on hand for immediate reversal if a problem develops.
The common, expected risks
Bruising and swelling are the most common side effects, and they are simply part of introducing a needle and a gel into tissue. Most patients see this resolve within a few days to a week, and I recommend avoiding blood thinners, alcohol, and strenuous exercise for a day or two beforehand to minimize it. Temporary lumps or firmness right after treatment are also common and usually smooth out as the product integrates and any swelling resolves, generally within one to two weeks.
Less common but still relatively minor
Some patients experience temporary asymmetry while swelling settles unevenly, which typically resolves on its own. Small nodules or firm areas can occasionally persist longer term, particularly with thicker filler placed too superficially, and these are usually manageable with time, massage, or dissolving if needed.
The rare but serious risk: vascular occlusion
This is the one I take most seriously and the one that drives most of my technique decisions. If filler is injected directly into a blood vessel, or placed in a way that compresses one, it can cut off blood supply to the surrounding tissue. Depending on the vessel involved, this can cause skin damage, and in the rare cases involving vessels connected to the eye, most commonly around the glabella and nose, vision loss. This is an emergency that requires immediate recognition and treatment with hyaluronidase, which is why I always have it on hand and why understanding facial vascular anatomy is central to safe injecting. It is also why I am cautious about certain high-risk areas and adjust my technique, injection depth, and pressure specifically around them.
Infection and other rare complications
Infection at the injection site is uncommon with proper sterile technique but is possible with any injection. Delayed inflammatory reactions, sometimes triggered by an unrelated illness or even a dental procedure months later, can occasionally occur with any filler and are typically manageable with anti-inflammatory treatment.
How risk is minimized in practice
The single biggest factor in avoiding serious complications is injector training and anatomical knowledge, not the product itself. I inject slowly, aspirate where appropriate, use blunt cannulas in higher-risk areas when it makes sense, and choose depth and technique based on the specific vascular anatomy of the area I am treating. Patients should feel comfortable asking their injector about their training and what their plan is if a complication occurs.
