Lips: Anatomy, Lip Filler, and Safety Care
The lips are one of the most requested areas in orofacial harmonization and one of the most sensitive to excess. They sit at the center of the lower third and weigh heavily in how age, femininity, and profile balance are read. A good lip plan respects the proportions of the face and each patient's anatomy, not a standard shape.
What are the anatomical boundaries of the lips?
For aesthetic assessment, the lips are divided into parts:
- Vermilion: the reddish portion, which patients usually call "the mouth".
- Vermilion border (white roll): the transition between the vermilion and the skin.
- Cupid's bow: the "M" shape of the upper lip border.
- Philtrum: the two vertical columns running from the cupid's bow to the columella of the nose.
- Tubercle: the central volume of the upper lip.
- Commissures: the mouth corners.
The orbicularis oris muscle forms the body of the lips. In proportion, many faces have a lower lip slightly fuller than the upper one, but this relationship varies between people and ethnicities.
Vessels and nerves to watch
- Superior and inferior labial arteries, branches of the facial artery, which run along the lips and anastomose with those of the opposite side.
- Facial artery, lateral to the commissures.
- Infraorbital (upper lip) and mental (lower lip) nerves, responsible for sensation.
The position of the labial arteries varies between patients. A vascular occlusion in the lips can cause necrosis of the mucosa and skin, and deserves attention even though it is a very common procedure.
What do patients usually ask for?
Requests vary quite a bit:
- "I want a fuller mouth."
- "My upper lip is too thin."
- "I want to define the outline of my mouth."
- "My lips are getting deflated with age."
- "I have these little lines above my mouth."
The small vertical lines on the upper lip are lip lines (barcode lines). They can be softened with delicate filler and other skin techniques, but they rarely disappear completely.
During the assessment, observe the proportion between the lips, the relationship with the nose and chin in profile, tooth show, asymmetries, and the tissue available. Requests based on photos of other people call for a conversation about what fits the patient's face.
Which procedures can be done on the lips?
The main procedure is lip filler with hyaluronic acid of a consistency suited to the area, soft enough to follow movement. The goals can be:
- Hydration and glow, with very small volumes.
- Definition, to outline the vermilion border and the cupid's bow.
- Volume, to increase the body of the lip.
- Asymmetry correction.
The lip is often treated together with mouth corner filler, so the new volume does not reinforce a drooping commissure look. Technique, plan, and instrument are the decision of the licensed professional, according to the rules of their professional council in Brazil.
What are the usual volumes for the lips?
Usual ranges in ml of hyaluronic acid, at the discretion of the licensed professional, after assessment:
| Goal | Usual range per session | Note |
|---|---|---|
| Hydration or fine-tuning | 0.3 to 0.5 ml | Patient's first experience |
| Definition and moderate volume | 0.5 to 1 ml | Most common case |
| Greater volume | 1 to 1.5 ml | Consider splitting across sessions |
| Durability | Generally 6 to 12 months | Varies with product and patient |
In patients who have never had filler, starting with a smaller volume and completing at a follow-up usually gives a more natural result.
Care, contraindications, and complications
General contraindications: active cold sores, active infection, pregnancy and breastfeeding, uncontrolled autoimmune disease, allergy to the components, and unrealistic expectations. A history of cold sores should be recorded, and preventive management is the professional's decision.
Reported complications:
- Significant swelling in the first few days, very common in the lips.
- Bruising.
- Facial asymmetry between the right and left sides.
- Lumps and palpable product.
- Migration of the product beyond the vermilion border.
- Vascular occlusion, with a risk of necrosis.
Hyaluronidase must be available in the clinic. See the overview of safety and complications.
How to assess lip proportion?
Before setting a volume, it is worth looking at the lips within the face, not in isolation. Some practical points for assessment:
- Relationship between upper and lower lip: in many faces the lower is slightly fuller. Reversing this relationship tends to look artificial.
- Upper lip height: long upper lips, with little tooth show at rest, may call for a different approach than pure volume.
- Profile: the position of the lips relative to the nose and chin changes the perception of projection. Sometimes what looks like a lack of lip is a lack of chin.
- Prior asymmetries: record them in a photo before the procedure, so you do not attribute to the filler a difference that was already there.
Facial assessment by thirds and standardized clinical photography help document this starting point.
How do the lips appear in Harmy?
In Harmy, the area is the Lips point in the marking step. After the frontal photo, the app detects the face on the device and shows the points with labels. Tap Lips to include them in the plan.
In the Plan, set the volume in ml (0.5 ml steps, from 0.5 to 5 ml). The simulation on this site used 1 ml. The AI respects the volume: the more ml, the more noticeable. It does not apply lipstick or makeup, does not change the expression, and does not retouch the skin: the projected lip keeps the color and texture of the original photo.
See the step by step in marking areas and volumes.
How to talk to the patient about the lips
The most common fear is "ending up with duck lips". An illustrative simulation with a moderate volume on the patient's photo shows that the goal can be subtle, and lets you compare 0.5 ml with 1 ml before deciding.
Present the projection as a support tool, never as a promise, and record the choice in the informed consent. To handle the most common doubts, see patient objections and answers.
Frequently asked questions
How long does lip filler last?
Generally 6 to 12 months, depending on the product, the volume, and the patient's metabolism. Lips move a lot, which tends to shorten the duration.
How many ml are used in lip filler?
Generally 0.5 to 1.5 ml per session, at the discretion of the licensed professional after assessment. Patients who have never had filler usually start with smaller volumes.
Can lip filler trigger cold sores?
The procedure can trigger an outbreak in people with a history of cold sores. That is why this history should be taken during the assessment, and preventive management is the professional's decision.
Can I see how the lip will look before filling?
You can show an illustrative simulation. In Harmy, you mark the Lips point on the patient's photo and set the volume in ml, and the projection shows only that change.
Harmy images are illustrative simulations generated by AI from the patient's photo to support the conversation between practitioner and patient. They are not a promise of results. Indication, technique, product and volume are solely the decision of the licensed practitioner. This content is for information only and does not replace a clinical assessment.