Where not to inject lip filler: Navigating Critical Zones

Medically Reviewed
Medically Reviewed by Dr. Aurora Kalmanson on
Written by Fillers Editorial Team, plastic surgery specialists.

Lip filler injections can enhance the fullness and shape of lips, but certain areas must be avoided to prevent serious complications. Key no-go zones include the vermillion border, high-risk vascular areas, and regions with dense nerve networks.

Incorrect injections can lead to vascular occlusion, tissue damage, inflammation, asymmetry, filler migration, and more. Understanding these risks and the anatomy of the lips is crucial for safe and effective lip enhancement. It’s crucial to seek treatment from experienced professionals who are knowledgeable in the delicate art of lip filler injections.

Anatomy and High-Risk Zones for Lip Filler Injections

A comprehensive understanding of lip anatomy and the recognition of high-risk zones are essential for safe and effective lip filler injections.

The Vermillion Border and Its Importance

The vermillion border is the distinct line where the pink-red lip tissue meets the facial skin. It plays a crucial role in the aesthetic contouring of the lips.

Risks of Incorrect Vermillion Border Injections: Injecting filler into the vermillion border requires precision to avoid a blurred or undefined lip line. Incorrect injections can lead to an unnatural appearance, with the lips losing their crisp, defined edge. Additionally, overfilling this area can cause a ‘duck lip’ look or the filler to spread into the surrounding skin, leading to an unattractive outcome. It’s essential to respect the natural anatomy of the vermillion border to maintain the lips’ harmony and balance with the rest of the face.

The Role of the Orbicularis Oris Muscle

Complications from Intramuscular Injections: The orbicularis oris muscle plays a vital role in lip movement and expression. When lip fillers are incorrectly injected into this muscle, patients may experience a range of complications. These can include difficulty articulating and performing basic functions like speaking, eating, and kissing. Intramuscular injections can also lead to unnatural stiffness and a loss of expressive capability. To avoid these issues, fillers should be carefully placed in the correct anatomical plane, and practitioners should have a detailed understanding of the muscle’s structure and function.

The Philtrum Columns and Cupid’s Bow

Maintaining Natural Contours: The philtrum columns and cupid’s bow are defining features of the upper lip, contributing to the lip’s aesthetic appeal and distinctiveness. Preserving the natural contours of these areas during filler injections is essential for a harmonious appearance. Overcorrection or improper placement of filler can distort the philtrum’s delicate ridges or flatten the cupid’s bow, leading to an unnatural look. Skilled injectors must navigate these areas with finesse, enhancing their prominence without compromising the lip’s natural shape and symmetry.

The Mucosal Membrane and Inner Lip Surface

Avoiding Deep Injections in the Mucosal Area: The mucosal membrane of the inner lip is a sensitive area that requires cautious consideration during filler injections. Deep injections in this zone can cause significant discomfort and increase the risk of complications such as prolonged swelling, hematoma formation, and even infection. The mucosal tissue’s unique properties require a gentle approach with fillers specifically designed for superficial placement. This ensures a smoother integration with the lip’s natural tissue and minimizes the potential for adverse reactions.

Lateral Lip Area and Nasolabial Folds

Vascular and Tissue Damage Risks: The lateral lip area and nasolabial folds are regions where precision in filler injections is crucial due to the presence of critical blood vessels and nerves. Incorrect injections here can lead to vascular compromise, resulting in tissue ischemia or necrosis. Additionally, the dynamic nature of the nasolabial folds means that fillers must be placed with care to avoid an unnatural appearance. Understanding the complex anatomy of these areas is key to preventing damage and achieving a natural, youthful result.

Direct Injection into Blood Vessels

Vascular Occlusion and Tissue Necrosis: Direct injection of lip filler into blood vessels is a critical error that can lead to vascular occlusion, an emergency situation where blood flow is blocked, starving tissues of oxygen and nutrients. This can result in tissue necrosis, a condition where lip tissue dies, potentially causing severe disfigurement. Symptoms such as blanching, pain, and changes in skin temperature should be treated immediately to prevent permanent damage. Practitioners must be adept at recognizing and managing these symptoms promptly to mitigate the risks of serious complications.

Area Between Upper Lip and Nose

Complex Vascular Network Considerations: The area between the upper lip and nose is characterized by a complex vascular network, making it a high-risk zone for filler injections. Precision is very important in this region to avoid interfering with the blood supply to the nose and upper lip. An in-depth understanding of the vascular anatomy is essential to prevent complications such as vascular occlusion. Practitioners should exercise extreme caution and use advanced techniques to ensure the safety and efficacy of treatments in this delicate area.

Frequently Asked Questions

What are the most common complications of incorrect lip filler injections?

The most common complications include vascular occlusion, tissue necrosis, inflammation, asymmetry, lumps, migration of the filler, and allergic reactions.

How can I ensure my lip filler procedure is safe?

Ensure your procedure is performed by a qualified and experienced professional who uses high-quality, FDA-approved fillers and adheres to strict hygienic standards.

Why is it important to avoid certain areas when injecting lip fillers?

Avoiding certain areas is crucial to prevent complications such as vascular occlusion, nerve damage, and asymmetry, ensuring a safe procedure and natural-looking results.

Are there any FDA warnings I should be aware of regarding lip fillers?

Yes, the FDA advises against using fillers in certain off-label areas like the breasts, buttocks, or between muscles due to risks of serious injury or death.


In conclusion, lip filler injections can significantly enhance one's appearance when done correctly. It is vital to understand the risks, high-risk zones, and the importance of a conservative approach to achieve the desired aesthetic results. Always seek a qualified professional who uses high-quality products and adheres to the highest safety standards. Stay informed about FDA guidelines and ensure a thorough consultation before proceeding with any lip filler treatment for a safe and satisfying experience.

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Singh, K., & Nooreyezdan, S. (2020). Nonvascular Complications of Injectable Fillers-Prevention and Management.

Dr. Aurora Kalmanson

Always Consult a Medical Specialist

The information provided in this blog is for informational and educational purposes only and should not be interpreted as personalized medical advice. It's crucial to understand that while we are medical professionals, the insights and advice we provide are based on general research and studies. They are not tailored to individual health needs or conditions. Thus, it is essential to consult directly with a healthcare provider who can offer personalized medical advice relevant to your specific situation.