3 DEEP Laser Principle Explained

There is a question that people who have received the 3DEEP lifting laser often ask in the clinic. "Why does it get better? What is the principle?" It is a curiosity that naturally follows because you felt the effect. In this article, rather than indications or expected effects, we will focus on explaining what the device called 3DEEP actually does inside the skin—its mechanism of action and principle. Once you know how radiofrequency energy turns into heat and why that heat touches collagen, the picture of the procedure becomes much clearer.

Although "laser" is attached to the name, the core working principle of 3DEEP is not light but radiofrequency energy. What is commonly called RF, radiofrequency, is a type of electromagnetic energy, usually sending an oscillating current in the 0.3 to 10 MHz band into the skin. Its starting point differs from the method of shooting light to handle pigment or the surface.

So how does current become heat? The key is the tissue's own resistance. As explained by Ohm's law, the tissues of our body have a certain resistance when current passes through. When the radiofrequency current rapidly changes direction, the ions and molecules inside the tissue oscillate along with it and collide with one another, and heat arises from this friction. In other words, the device does not heat the skin from the outside; rather, the skin tissue itself resists and generates heat from within. This is precisely the basic mechanism of radiofrequency summarized in U.S. dermatology literature.

The way radiofrequency is delivered is broadly divided into two branches. It is also a part often explained by drawing a picture in the clinic.

• In the monopolar method, the current starting from one electrode passes through the body and flows to a grounding pad far away. Because the path is long, the energy goes in deep, but as deep as it goes, pain or epidermal temperature management can be tricky.
• In the bipolar method, the current flows only between two electrodes placed close together. Because the path is short, it is stable, but the reach depth tends to be shallow, about half the gap between the two electrodes, so it is hard to reach deep layers.

The two methods have clear pros and cons. Monopolar has depth as a strength, and bipolar has stability and surface safety. As Director Lee Dong-hee pointed out in the original article, if you use the two separately, the weakness of one side remains as is. This is where the design intent of 3DEEP is revealed.

The most distinctive part of 3DEEP's working principle is that it ties monopolar and bipolar together in one place. In medical literature, such a method is called combined or multi-source radiofrequency. With multiple electrodes matching their phases and exchanging energy, it is a structure that distributes heat across multiple depths, from the shallow layer just beneath the epidermis to the deep layers of the dermis.

In this way, the design intent of using the depth of monopolar and the stability of bipolar at once holds. It is the concept of handling the skin structure three-dimensionally by aiming at the collagen of the deep and shallow layers simultaneously. Studies handling facial wrinkles and skin elasticity with hybrid-type radiofrequency have been reported, and there may be individual variation in results. You can understand it as the same line of thinking as procedures using a similar combined principle, such as Big Hit Lifting, or Collagen Toning, which handles the collagen environment of the dermis.

If you are curious about the principle, it is fine to ask sufficiently before the procedure. Consult about the 3DEEP principle

So what does the warmed heat do inside the skin? The mechanism of action is easier to understand when divided broadly into two stages.

The first stage is immediate collagen contraction. When the dermis temperature rises above a certain level, the triple-helix structure of the existing collagen fibers is partially denatured and shortens in length. The literature explains this immediate contraction as the first response of RF thermal action.

The second stage is collagen regeneration that occurs over time, so-called neocollagenesis. The thermal stimulation sends a mild recovery signal to the tissue, and in this process, heat shock proteins involved in the folding and stabilization of collagen increase and fibroblasts are activated. As a result, it is reported to lead to a flow in which new type I collagen and elastin are made over time. Radiofrequency skin regeneration studies archived in the U.S. National Library of Medicine deal with this two-stage mechanism.

A concept that cannot be left out of the working principle of radiofrequency procedures is selective heating. The goal is to heat the dermis and the layers beneath it, not to burn the outermost epidermis. The literature explains keeping the epidermal surface at a relatively low temperature while raising the dermis temperature to the range in which collagen responds, as the key to safe operation.

In the clinic, this balance is precisely the most important task in radiofrequency device design. If it is too weak, the dermis does not respond sufficiently; if the balance breaks, the epidermis takes a burden. That 3DEEP is designed to deliver energy divided across multiple depths can also be seen as an approach to strike this balance. Its starting point of safety strategy itself differs from the way skin lasers, which handle the surface, have light absorbed.

3DEEP contains several automatic skin-sensing feedback mechanisms. The technical basis for the part where Director Lee Dong-hee explained in the original article that it can be used without concern about burns is precisely this.

The principle is as follows. Even in the same person, the tissue's resistance, that is, impedance, differs by site, and as the procedure proceeds the temperature also keeps changing. The feedback mechanism reads this change in real time and adjusts the energy delivery. It is a structure in which the balance of selective heating explained earlier—that is, the balance of heating the dermis sufficiently while not overheating the epidermis—is assisted not only by human sense but together by the device. This is only a general working principle, and the actual procedure intensity and suitability may differ depending on one's skin condition, and consultation through an examination is needed.

In summary, the mechanism of action of 3DEEP is summarized in three sentences. Radiofrequency current makes heat within the dermis through the tissue's resistance; that heat contracts the existing collagen while simultaneously sending a signal for new collagen to be made; and that process is carried out in a balanced way while protecting the epidermis. Once you know the principle, what was a vague procedure is drawn much more clearly. If you read it together with articles dealing with similar concerns—such as why skin loss of elasticity is connected to a collagen problem in the dermis, or the story of vaginal laxity and the principle of tightening laser treatment—you will grasp the big picture of heat-based procedures.

Even if the principle is the same, the suitable intensity and method differ from person to person. If you want to be consulted step by step starting from the principle, please ask via chat.

Author: Lee Dong-hee Chief Director · Obstetrician-Gynecologist · View staff profile

First published November 22, 2023 · Last reviewed May 30, 2026

References: Plastic and Reconstructive Surgery Global Open (2020), Dermatological Reviews (2022), National Library of Medicine PMC (2010)

This article is intended to provide general health information and does not replace individual diagnosis or treatment. If you have symptoms, please consult through a medical examination.