Density and Oligio — Before Comparing, You Have to Settle Which Oligio

Oligio X is an extension within radiofrequency; Oligio Kiss adds a different kind of energy to radiofrequency — the directions themselves differ. In this article “Oligio” refers to the monopolar radiofrequency base unit unless stated otherwise. The three products are distinguished in why Oligio Kiss put two things in one device.

The several rows reading “we could not verify” mean we could not find that value in the manufacturer’s published specifications, not that the feature is absent. We have left it as written so as not to blur that distinction.

What Density puts forward is that it switches polarity in sequence. In monopolar the current passes through the body and exits at a return pad; in bipolar it flows only in the narrow span between two electrodes.

But what sets the depth is not polarity itself but the shape and arrangement of the electrodes — for monopolar the heating depth is governed by the size of the electrode, for bipolar by the spacing between electrodes. The presence of a return pad only determines whether current passes through the body; it does not determine the current distribution a few millimetres beneath the surface. In fact, for a small monopolar electrode the heating falls off as the fourth power of the sum of the electrode radius and the distance, so a 0.5 mm radius electrode penetrates only about 140 µm.

This mechanism does not mean “Density gives a better result than Oligio.” There is no study comparing the two devices in humans. A description of mechanism and a clinical result are sentences at different levels. The relationship between polarity and depth is detailed in monopolar and bipolar — what differs.

The key point is that neither has a control group. Without a control you cannot tell how much of the observed change was due to the treatment. Across radiofrequency lifting generally, of the 15 papers and 1,230 people gathered by the 2026 systematic review, only one was a randomised controlled trial.

There is a judgement that comes before the device name.

• Is this problem in radiofrequency’s domain? Radiofrequency lifting treats the dermis and the structures beneath it with heat, and laxity is its domain. Skin that is thin and dull belongs to the injectable domain. The two often occur together, and then we plan the order separately. Set out in booster first or lifting first.
• What neither can solve. Hollowed volume, pigment and the surgical excision of excess skin are outside the scope of both devices.
• When to judge. The assessment point for radiofrequency is not the same day but two to three months later. In an assessor-blinded study of 20 Korean women, radiofrequency was not significant on clinician assessment at 4 weeks but was at 12 weeks, with a peak at 4–6 months.

Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Every study cited above is given together with its design, its size and the limitations the authors themselves recorded, and where we could not find data, we have said that we could not find any.