Threads with barbs and without barbs. What changes in the final result?

Threads with barbs (cogs) and smooth threads have different roles. Smooth threads primarily work to increase collagen in the skin, and their lifting power is limited, as understood in the field[1]. Threads with barbs grasp tissue and move its position—in other words, lifting itself is the job[1].

What do the barbs do?

They catch on tissue and hold the lifted position in place. Textbooks describe threaded lifting with barbed Thread lift as a low-burden technique in which threads are inserted through the skin to lift the soft tissues of the face and neck[2]. Today's threads are divided broadly into two types based on barb direction: those with bidirectional barbs and those with multidirectional barbs[3]。A study has also been published that measures and compares the fixation strength when these two are combined[3].

How do you differentiate from smooth Thread lift?

It depends on whether you want to improve skin quality or move position. Smooth single-line Thread lift causes new collagen to form and improves skin quality, but the lifting force is limited[1]。The barbed Thread lift is responsible for grasping and restoring position[1]。If you are seeking Sagging (skin laxity) improvement but only the former is proposed, verify that it aligns with your goal.

What changes with thickness and barb size?

The weight of tissue that can be handled changes. Thick Thread lift with large barbs are suited for lifting heavy, sagging lower facial tissue, while thin Thread lift with small barbs are suited for delicate areas like around the eyes[4]Even with the same **Thread lift**, it becomes easier to understand if you think of it as approaching a different treatment depending on which thread you choose.

PDO threads are designed to cause a mild inflammatory response as they dissolve, stimulating the activity of fibroblasts to create new collagen.[4]It works both to lift immediately and to produce skin changes that appear afterward.[4].

If the material is different, what changes?

The speed of dissolution and how it works on the skin. PDO threads are said to work within the dermis for approximately 6 months.[5]PLLA is a material made from lactic acid and has the property of adding volume to sagging areas.[5]PCL is the newest monofilament thread, and animal experiments on aged rats have reported that it increases dermal collagen density more effectively than PDO or PLLA.[5]Since these are animal experiment results, the same may not necessarily apply to humans.[5].

When are barbed threads insufficient?

When there is excess skin and heavy Sagging (skin laxity) is present. Since threads do not remove skin, they cannot reduce the excess skin itself.[2]In terms of research quality, systematic reviews point out that many reports have small case numbers and short observation periods, with insufficient objective evaluation metrics.[6]In actual practice, the use pattern is increasingly shifting toward combination with other treatments rather than as a standalone therapy.[7].

During your consultation, ask whether the thread you plan to use has barbs, what its thickness and material are, and what the combination aims to achieve. If you can get a separate explanation of whether Sagging (skin laxity) is from skin looseness or descent of deeper layers, you can get a sense of whether threads will be sufficient.