WHAT IS BEST FOR SKIN TIGHTENING?
A very common question I am asked is what is the difference between unipolar, monopolar, bipolar and multipolar (i.e. tripolar, tetrapolar, octipolar) radiofrequency? Which one is best for skin tightening?
First of all, let's make it clear: there are only two poles in electricity: plus and minus. That's basic Physics from high school. So all these names (tripolar, tetrapolar, octipolar whatever-polar) are a misnomer and a little bit of a gimmick, especially when it comes to eight poles, which is an overkill and unnecessary (more on that later). Let me first explain what is monopolar and bipolar, and then I will move to multipolar and unipolar.
But to answer the question on the title of this paragraph, let me just say that for both deep and superficial skin tightening, monopolar radiofrequency wins hands down.
WHAT IS MONOPOLAR RADIO FREQUENCY?
In monopolar RF the (+) and (-) poles are located quite far apart from each other. As a result, the current has no other choice but to traverse through ALL skin layers after entering the skin, travel through the body to the other pole, and exit there.
This means that with monopolar RF, and depending on some other factors too, we can treat not only the skin surface (epidermis) but also the middle skin layer (dermis), the deepest skin layer (hypodermis/subdermis) and even the subcutaneous fat deposits below the skin itself.
As I mentioned above, how deep we treat depends on some other factors too, not just on bipolar/monopolar arrangement. However, in most setups monopolar RF allows us the opportunity to go quite deep. Unfortunately this is not the case with bipolar RF, which is restricted to quite superficial treatment, no matter what gimmicks are used to make the current "go deeper".
WHAT IS BIPOLAR RADIO-FREQUENCY?
With bipolar radiofrequency the plus (+) and minus (-) poles are located very close to each other - too close for deep treatment.
Because the poles are close to each other (in most machines they are almost adjacent to each other), the current has no other choice but to briefly and superficially penetrate the skin (as little as one millimetre (i.e. the maximum depth of epidermis) and then exit the skin again from the other pole, not very far from where it entered. Quite often the "trajectory" of the current spans just the epidermis.
This means that if we want to properly treat the dermis (and even more so if we want to treat the hypodermis or subcutaneous fat), we must first literally burn the epidermis, which is in the way and absorbs almost all of the current. Because nobody would even want to burn the epidermis, treatment intensity is adjusted at lower levels. This keeps the epidermis happy but deeper skin layers are not treated properly.
Epidermal heating gives the impression of a very strong treatment, with lots of redness and quite often irritation, and there is some superficial tightening. However, not much collagen/elastin production is stimulated in the dermis/subdermis below and definitely no cellulite fat or deep fat reduction (which is located even deeper) ever occurs.
If intensity is increased, in order to work on deeper skin layers and produce some skin firming/lifting, the epidermis is burned/irritated and/or severe pain is experienced, hence some of these burn pictures and extreme pain stories in review websites.
In a few words, bipolar RF is just too superficial. Period.