Lip Flip Injection Sites Explained: Techniques, Dosage, and Safety Tips

Introduction

In recent years, lip flip injection has become increasingly popular in aesthetic clinics. Also sometimes called a “smile lip injection”, this procedure uses a small amount of Botox injected into specific points on the upper lip. It gently relaxes the muscles, allowing the lips that were slightly tucked inward to naturally flip outward, showing more of the lip’s color and creating a soft, light, and naturally “smiling” appearance.

Lip Flip Injection Principle

The core principle of a Lip Flip Injection is to selectively relax the muscles around the upper lip using Botox, which changes the dynamic tension of the lips and allows the upper lip to naturally flip upward.

Mechanism:

Botox works on the superficial fibers of the orbicularis oris muscle, reducing muscle contraction at the injection site. Once the muscle relaxes, the upper lip that was slightly tucked inward gently flips outward, revealing more of the lip color.

Key Effects:

· The upper lip takes on a natural, soft curl, giving a gentler smile;
· Lip volume is not increased, but the lip line and shape are improved;
· Results typically last 2–3 months, gradually returning as muscle activity resumes.

As shown in the image below, you can see the difference in the lips before and after a Lip Flip Injection.

Common Lip Flip Injection Sites

To achieve a natural upward flip of the upper lip, the common injection points for a lip flip are usually located at specific areas on the upper lip.

A. Cupid’s Bow (Sides of the Upper Lip Peak)

• Location:
  The Cupid’s Bow is at the center of the upper lip and forms the two most prominent peaks of the upper lip contour, usually located on either side of the midline below the nose. When viewed from the front, it creates the two tips of the “M”-shaped upper lip line. The Lip Flip injection points are located on the sides of these peaks, close to the lip border but not too close to the inner red lip, to avoid affecting the natural exposure of the lip color.

• Why Inject Here:
  Injecting on the sides of the Cupid’s Bow gently relaxes the fibers above the orbicularis oris muscle, allowing the center of the upper lip to naturally flip upward. This strengthens the lip peak and creates a more natural smile.

• Tips for Injection:
  - Use approximately 0.5–1 unit of Botox per side;
  - Inject into the superficial muscle layer and maintain symmetry;
  - Avoid over-injection to prevent excessive upward flip or a stiff appearance in the middle of the upper lip.

B：Upper Lip Sides (Vermilion Border)

• Location:
  The upper lip sides are located along the border between the red lip and the surrounding skin, near the corners of the mouth but not directly above them. From a front view, these injection points are along the outer edge of the upper lip, between the center of the lip and the corners.

• Why Inject Here:
  Injecting the upper lip sides helps naturally lift the corners of the mouth, improving the lip contour during a smile and creating a softer, more three-dimensional appearance.

• Tips for Injection:
  - Use approximately 0.5–1 unit of Botox per side;
  - Inject into the superficial layer and maintain symmetry;
  - Avoid over-injection to prevent affecting the corner expression or causing localized stiffness;
  - Coordinate with the central Cupid’s Bow injection points to ensure the upper lip has a natural overall shape.

Note: A standard Lip Flip injection is usually completed with four points on the upper lip.

Is the lower lip necessary?
Injecting the lower lip is generally optional. It is only considered when there is lip imbalance or tightness in the lower lip, to help balance the proportions between the upper and lower lips and create a more harmonious smile.

Lip Flip Injection Sites V.S Lip Filler Injection Sites

How to Master Lip Flip Injection Sites?

· Theory Study: Learn the anatomy of the lips and understand the main injection points and expected effects on the upper lip.
· Injection Point Mapping: Mark the Cupid’s Bow sides, upper lip sides, and optionally the lower lip on a model or diagram.
· Practice Injections: Use a training model to practice shallow injections, controlling depth, dose, and needle angle. To get more familiar with the injection points and feel, you can use our lip injection practice model for repeated practice, improving accuracy and confidence.
· Repetition: Practice multiple times to enhance precision and symmetry.
· Pre- and Post-Procedure Communication: Confirm the client’s desired results beforehand and observe/record outcomes afterward to optimize future procedures.

Summary

Lip Flip injections are ideal for clients seeking a natural, well-defined smile without adding lip volume. Mastering the injection points, dosage, and superficial technique is key, along with proper pre-procedure consultation and post-procedure guidance to enhance client satisfaction.

To practice and become confident with lip flip injection sites, you can use our facial injection model series, which includes both the single lip injection practice model and the more cost-effective full-face injection practice model.

📰Related Article:

· Botox Injection Sites Guide: Standard Charts, Risks, and Practical Tips