Dermal fillers have become one of the most popular non-surgical cosmetic treatments worldwide, promising a youthful appearance with minimal downtime. When administered correctly by a qualified professional, hyaluronic acid (HA) fillers can provide safe, reversible, and natural-looking results. However, the rise in popularity has also led to a parallel rise in complications, particularly when treatments are performed by unlicensed individuals or when the wrong substances—namely silicone—are used. Understanding the types of complications that can arise is crucial for anyone considering this procedure.

The Golden Rule: Know What Is Being Injected

Before discussing complications, there is one non-negotiable principle you must follow. Do not let anyone inject you with silicone.

If you are considering filler, your first question to the provider must be: “What filler are you using? Is it HA filler or silicone?”

Hyaluronic acid (HA) fillers (such as Juvederm, Restylane, Belotero, Maili or Saypha) are the industry standard. HA is a substance naturally found in the body, making these fillers temporary and, most importantly, reversible.

Silicone is a permanent synthetic oil. Unlike HA, silicone cannot be removed without surgeries. If a complication occurs—migration, infection, or disfigurement—you cannot inject an enzyme to dissolve it. The only solution is invasive surgical excision, which often leaves significant scarring. Reputable, qualified medical professionals do not use liquid silicone for facial volumization. If a provider offers it, walk away immediately.

Vascular Occlusion: The Emergency

The most urgent complication of dermal fillers is vascular occlusion. This occurs when filler is accidentally injected into an artery or when the filler compresses a vessel. By blocking blood flow, the filler starves the surrounding tissue of oxygen.

If not recognized within hours, this leads to tissue necrosis (death of the skin) or, in the worst-case scenario involving the glabellar region (between the brows), blindness. Signs of occlusion include sudden severe pain, blanching (whitening) of the skin, mottling, and delayed capillary refill. Treatment requires immediate injection of hyaluronidase (the enzyme that dissolves HA filler) to break down the product and restore blood flow. This is why HA filler is safer; it is reversible. With silicone, there is no such enzyme—once a vessel is blocked, the damage is often irreversible.

Nodules and Granulomas

Lumps and bumps are among the most common complications. They are categorized as either inflammatory or non-inflammatory.

• Non-inflammatory nodules often appear soon after injection due to improper technique, overcorrection, or superficial placement. These can sometimes be massaged or dissolved.
• Granulomas are delayed inflammatory reactions that can occur months or even years after injection. The immune system suddenly identifies the filler as a foreign body and mounts an attack, causing hard, painful, red bumps under the skin. While HA granulomas can often be treated with steroids or hyaluronidase, silicone granulomas are notoriously difficult to treat. Because silicone is permanent and the body cannot break it down, silicone granulomas often require surgical excision to remove the hardened, inflamed tissue.

Infection 

Infections can be categorized as bacterial or biofilm-related. Bacterial infections occur soon after injection, presenting with erythema (redness), warmth, pus, and fever. This is usually due to poor aseptic technique.

Biofilms are more insidious. They occur when bacteria colonize the filler material, creating a persistent, low-grade infection that does not respond well to standard antibiotics. In cases of silicone, biofilms can be nearly impossible to eradicate without surgically removing the silicone itself.

Tyndall Effect and Discoloration

This is a technical complication often resulting from superficial injection. The Tyndall effect refers to a bluish discoloration visible under the thin skin of the tear troughs or lips. It occurs when filler is placed too close to the surface, causing light to scatter. While this is easily corrected with hyaluronidase in HA fillers, permanent silicone placed too superficially will leave a permanent blue tint that can only be removed by cutting out the affected tissue.

Edema and Swelling

Prolonged or delayed swelling is a common complication. While acute swelling is normal for the first 24 to 72 hours, some patients experience intermittent swelling months or years later, often triggered by illness, allergies, or dental work. This is particularly common with permanent fillers like silicone, where the persistent foreign body creates a reservoir for fluid accumulation.

Migration

Filler does not always stay where it is placed. Inadequate product consistency or poor injection technique can cause filler to migrate to adjacent areas. The most infamous example is over-inflation of the lips, where filler migrates above the vermilion border, creating the dreaded “filler mustache.” While HA migration can be dissolved, silicone migration is permanent. Once liquid silicone moves to an unintended area (such as the upper lip or under the eyes), it can only be removed through complex surgery, often resulting in significant disfigurement.

The difference between a successful filler treatment and a medical nightmare often comes down to two factors: the substance used and the injector’s qualifications. Hyaluronic acid fillers offer a safety net—they can be dissolved, allowing for correction of errors. Silicone offers no such safety. It is permanent, un-forgiving, and when complications arise, they cannot be resolved with a simple injection; they require surgeries that often leave permanent scars.

If you are considering dermal fillers, always verify that your provider is a licensed medical professional. Ask specifically what product they are using. If the answer is “silicone” or a permanent industrial-grade substance, seek treatment elsewhere. In the world of aesthetics, reversibility is safety—and safety should always be the priority.