Capacitive RF vs resistive RF treatment

Capacitive vs resistive radiofrequency treatment: what is best for cellulite and skin tightening?

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• Resistive RF vs capacitive RF: what are they and what do they practically mean for you?

• What is resistive radio frequency?

• What is capacitive radio frequency?

• Deep vs superficial radio frequency

• Capacitive RF for superficial treatment, resistive RF for deep treatment

• How do I know what kind of RF treatment I am receiving?

• RF at very high frequencies is by definition always capacitive

• Check our professional consultancy for a masterclass in radiofrequency, ultrasound cavitation, cellulite and skin tightening

Resistive RF vs capacitive RF: what are they and what do they practically mean for you?

There are many iterations of radio frequency technology for aesthetic treatments, depending on how the technology is applied. So we may have:

• Bipolar vs monopolar vs unipolar RF

• Capacitive vs resistive RF

• Destructive vs stimulative RF

• Low frequency vs high frequency RF

On this article we are discussing the distinction between capacitive and resistive radio frequency and how it can affect the depth, quality and safety of treatment offered.

This aspect is not as well known as bipolar vs monopolar vs tripolar, but it is equally important if you wish to choose correctly the best RF radiofrequency machine for your clients/patients or the best radio frequency treatment for yourself.

What is resistive radio frequency?

In simple terms, when the radiofrequency handpiece that gets in contact with the body during treatment is made of uncoated metal, and thereby allows electricity to pass through to the skin relatively unimpeded, then we are talking about resistive radiofrequency.

This is because in this case the surface of the skin (epidermis) acts as a resistor.

Resistive RF is applied with the aid of a gel, glycerine or cream.

As in this case the skin has very low impedance/resistance (always depending on the type of contact gel/cream used too), the skin surface does not get too hot, allowing the radio frequency current to work deeper, where there is much more impedance/resistance from the fat, especially if we also use monopolar RF.

So combined resistive AND monopolar RF results in deeper treatment.

Resistive RF tends to be low frequency radiofrequency, almost always <1,000 kHz.

What is capacitive radio frequency?

When the radiofrequency handpiece that gets in contact with the body is coated with a ceramic, teflon, plastic or other material that does not conduct electricity, and thereby necessitates electricity to "jump" through to the skin, then we are talking about capacitive radio frequency.

This is because in this case the ceramic/teflon/plastic coating of the handpiece acts as a capacitor, while the epidermis and the contact medium act as a combination of capacitors and resistors.

In this case, heat develops in the interface between skin and handpiece, which is covered with contact medium (gel, cream, glycerine etc), so treatment is unavoidably very superficial, and the epidermis gets very hot.

This means that capacitive RF treatment is more superficial, especially so when a bipolar/multipolar electrode arrangement is used. With a monopolar capacitive arrangement, treatment is a bit deeper, but still very very superficial. So:

• Combined capacitive AND bipolar/tripolar/multipolar RF results in superficial treatment

• Combined capacitive AND monopolar RF results in somewhat deep treatment

Capacitive RF is usually of higher frequency, typically >1,000 KHz, but low frequrncy capacitive machines (from around 450kHz) also exist.

Deep vs superficial radio frequency

There is nothing wrong with superficial/epidermal treatment, if you are trying to treat acne or perhaps dilated skin pores.

But superficial treatment is a waste when it comes to skin tightening (especially deep skin tightening) and cellulite reduction, as these require treatment deep inside the skin.

In any case, for superficial treatment, you do not need a multi-thousand pound RF machine to heat the epidermis. You can do that with an infrared lamp, hot pack, sauna or even hot water, at a much lower cost - or no cost.

Radiofrequency was developed in order to help us provide deep treatment, not to be an expensive superficial treatment.

Capacitive RF for superficial treatment, resistive RF for deep treatment

To treat anything deeper than the epidermis and the papillary/superficial dermis (ie for anything other than acne, superficial skin tightening, simple facials), capacitive radiofrequency is not such a smart solution compared to resistive RF as it:

• Is generally very superficial

• Requires very high RF generator power to provide decent power on the skin itself

• Necessitates the need of superficial cooling in order to protect the epidermis

For treatment applications of deeper tissues (reticular dermis, hypodermis and superficial fascia), such as cellulite removal and deep skin tightening, resistive radiofrequency is a much smarter option, as it generally acts deeper (with depth still depending on other factors, though).

On the other hand, capacitive RF is a useful addition to a system that also provides a resistive option, as it offers a nice, gentle superficial treatment.

This allows the operator to switch between deep, medium or superficial treatment, according to the needs of the client.

A handful of quality machines offer both a capacitive and a resistive option to offer full flexibility to the operator.

However, capacitive RF is not necessarily needed for superficial treatment, as with the right settings and treatment medium used, superficial treatment can also be applied with resistive RF.

RF at very high frequencies is by definition always capacitive

This is because the stratum corneum outer epidermal layer offers no resistance at those frequencies, unless wetted by a treatment medium. Such high frequencies used in physiotherapy and beauty are 27.1 MHz (shortwave RF), 40.68MHz (shortwave RF), 2.45GHz (microwave RF).

This is a whole different category to the RF discussed above and these treatments at these frequencies can be anything from superficial to deep, depending on equipment design and/or treatment settings.

How do I know what kind of RF treatment I am receiving?

The answer is very simple:

• If the handpiece makes contact with your skin via a stainless steel tip, then you are having resistive treatment

• If the tip is made of ceramic, teflon or plastic, then treatment is capacitive

The issue between capacitive vs resistive is of less importance than the issue between bipolar and monopolar radio frequency.

This is because monopolar RF is always superior to bipolar RF.

So if you use a bipolar machine, your hands are tied completely with such equipment, regardless of how much experience you have.

On the other hand, a well-trained, experienced and knowledgable therapist may generally be able to do a good job with either a capacitive or resistive machine, as long as the machine is monopolar.

Check our professional consultancy for a masterclass in radiofrequency, ultrasound cavitation, cellulite and skin tightening

Do you want to deeply understand radiofrequency, ultrasound cavitation, cellulite and skin tightening? Attend a half-day, 1-day, 2-day or 3-day professional consultancy / one-to-one training and confidently offer your clients the safest, strongest and most effective treatment possible. Service available via Zoom or at our central London practice.