“I have intensely studied the biophysics of radiofrequency and have also applied RF treatments for more than two decades. What I find truly shocking is that manufacturers of excellent machines employ not very smart people to write the training manuals and materials. One example is when kJ count is being used to determine the length and intensity of continuous movement RF / cavitation treatment, which results in thousands of therapists providing inferior treatment to their clients.”
How do you determine RF / ultrasound treatment strength?
KiloJoule count for radiofrequency / ultrasound treatments makes no sense today | In summary
Total energy applied during treatment means nothing (for continuous movement RF or ultrasound)
If kJoules mean nothing, how do we measure treatment intensity?
Infrared thermometer to the rescue
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KiloJoule count for radiofrequency / ultrasound treatments makes no sense today | In summary
In modern radiofrequency (RF) and ultrasound cavitation treatments using continuous movement techniques, the total energy delivered, measured in kilojoules (kJ), is largely irrelevant. Unlike older static methods (stamp or pulse), where energy count per area mattered, continuous movement treatments focus on maintaining effective therapeutic temperatures for a sustained period.
Delivering the same amount of energy over different durations can lead to vastly different outcomes—from effective fat reduction and skin tightening at optimal temperatures (around 39–41°C), to ineffective results or even burns if the temperature is too low or too high.
The key to effective treatment lies in accurately controlling temperature and treatment time, not total energy. Therefore, using a reliable infrared thermometer to monitor skin temperature is essential.
Relying on total kJ alone can lead to underperformance or harm, highlighting the need for improved therapist training and a shift away from outdated energy-based protocols still promoted by some equipment manufacturers.
Total energy applied during treatment means nothing (for continuous movement RF or ultrasound)
Back in the early 2000s, when RF treatments were static (using the “stamp” or “pulse” method), counting the total amount of energy applied on the skin (as measured in Joules, kiloJoules to be precise), meant something: it signified how strong the treatment was for each ‘pulse’ on that particular area.
Today this stamp/pulse method is only being used for one specific ultrasound machine, one specific RF machine and for all RF microneedling and HIFU treatments.
If you have been following this blog you would know that we are not big fans of the stamp method (and consequently HIFU and RF microneedling), as at reasonable intensities it limits effectiveness/efficiency and at high intensities it causes burns.
Nowadays most RF and ultrasound cavitation treatments use the continuous movement method, as opposed to the stamp/pulse method. This allows us to provide high amounts of energy on the tissues per unit of time, for better efficiency and without skin burning - as long as a well trained and responsible therapist provides the treatment.
So for continuous movement RF and continuous movement ultrasound cavitation, total energy used means nothing.
This is because if one applies e.g. 100kJ (kiloJoules) of RF or cavitation over 20 minutes it will not be at all the same treatment as one where 100kJ are applied over 40 minutes on the same body area.
In the former case the tissue could be treated at, say 39-41°C for 20 minutes (great for good results) while in the latter case it could be treated at, say, 36-38°C for 40 minutes (i.e. pointless).
Despite the longer session time, treatment in the second case will produce no results, simply because at 36-38°C no fat is released and no skin tightening occurs, i.e. a waste of 40 minutes.
In both cases the therapist would have achieved what the “protocol” suggested, i.e. 50kJ of treatment on the same area - but results couldn't be any more different.
Even worse, if someone completed the same 100kJ treatment in 10 minutes skin temp could rise to, say, 45ºC, in which case there could possibly a tissue burn.
Unfortunately, many good aesthetic equipment manufacturers still use total Joule power in their protocols for different treatment areas, which is absolutely pointless, and at some point they have to up their game when it comes to therapist training protocols.
In one case a client can have amazing results with 100kJ; in another they have a pointless RF/ultrasound massage; and in another they may get burned.
For continuous movement ultrasound and continuous movement radiofrequency, total energy power (measured in kJ) means little.
If kJoules mean nothing, how do we measure treatment intensity?
It’s simple. For the client (and consequently for us therapists) what matters is results. And results in radiofrequency (and quite often in ultrasound cavitation) depend on how long a good therapeutic temperature is maintained for a given amount of time.
So for our example above, what would make sense is to focus on keeping the particular area of the body at a particular temperature for an X amount of time - all to be determined according to the client’s needs.
If we applied the same temperature for half the time, treatment would probably be inadequate; while if we did so for double the time treatment would probably be excessive.
Infrared thermometer to the rescue
So for continuous movement RF and ultrasound, forget about total energy used, buy a good infrared thermometer and measure treatment temperature and treatment time instead. This will make more sense in terms of treatment efficacy and treatment safety too.
(Don’t save the pennies though, as most IR thermometers are quite inaccurate and you may think you treat at 40°C when in reality you only reach 38°C; this may be fine for cooking but it is a big difference for our purposes.)
Please note: all the above temperatures, total treatment energy and treatment time are imaginary, for example’s sake. Also, deep acting treatment will provide higher deep skin temperatures than more superficially acting ones, even if both display the same skin surface temperature on the infrared thermometer.
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At LipoTherapeia we have specialised 100% in skin tightening and cellulite reduction for more than two decades and 20,000+ sessions.
This is all we study and practise every day and have researched and tried hands-on all the important skin tightening equipment and their manufacturers.
As strong, deep acting radiofrequency and deep-acting, high-power ultrasound cavitation are the technologies of choice for skin tightening and cellulite reduction, we have invested in the best RF/ultrasound technologies in the world.
(Of course, we keep looking for new technologies every day and if/when a better technology materialises we will be the first to provide it. However, we will never follow the latest ineffective gimmick, just because it’s good marketing to offer the latest hyped up - yet ineffective and/or unsafe treatment.)
Furthermore, over the last two decades we have developed advanced RF and cavitation treatment protocols in order to make the most of our technologies, for maximum results, naturally and safely.
And for even better, faster results, we now combine our RF/ultrasound treatments with high-power red/infrared light LED treatment.
Our radiofrequency/ultrasound/LED treatments are comfortable, pain-free, downtime-free, injection-free, 99.5%+ safe and always non-invasive.
(No unsafe and ineffective RF microneedling or HIFU and no safe but ineffective acoustic wave therapy, superficial RF (bipolar/tripolar/multipolar etc), low power RF/cavitation, electrical muscle stimulation, lymphatic massage, cupping, dry brushing and no ridiculous bum bum creams.)
Our focus is on honest, realistic, science-based treatment, combined with caring, professional service, with a smile.
We will be pleased to see you, assess your cellulite, skin laxity or fibrosis, listen to your story, discuss your case and offer you the best possible treatment.
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Why train with The Cellulite School™?
We all know that training in cellulite reduction and skin tightening is as basic as it gets. It is typically a 4-6 hour training, involving only basic instruction from the manufacturer on how operators can use the machine; lots of myths, erroneous information and misconceptions; and some basic health and safety on how to use the machine.
There is no proper, real training in the science or cellulite, skin tightening, radiofrequency, ultrasound and all related technologies is non-existent - worldwide.
Do you want to deeply understand radiofrequency, ultrasound cavitation, LED phototherapy, cellulite and skin tightening?
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