What Are Mono Threads? Smooth Threads and Their Intended Effect

Mono threads are thin, smooth threads, typically made of polydioxanone (PDO), a material used in dissolvable stitches. This page is part of our guide to mono threads.

What they look like

They are very fine, smooth filaments with no barbs or cones, usually supplied in a fine needle or cannula. Many are placed in a mesh or crisscross pattern.

The intended purpose

The aim is not to lift tissue mechanically. Instead, as the thread dissolves, the body responds around it, which is hoped to stimulate collagen and improve skin firmness, texture or tone. This is sometimes called biostimulation.

Where they are commonly used

Mono threads are mainly used on facial and neck skin, and in some body areas, to improve skin quality. They are not designed to add substantial volume.

Breast use

Mono threads in the breast are marketed with claims of tightening skin, improving the look of the chest or enhancing shape. Evidence for a lasting increase in breast volume is not established.

Material and duration

PDO is absorbed over several months. Any effect on skin may last longer than the thread itself, according to some providers, but the published evidence is limited and variable.

Questions to ask

• What material are the threads and how long do they dissolve?
• What exactly is the expected effect?
• Is there evidence for breast skin?