By Raymond Schoeman
This is something that I would never have thought of doing, both offering as a service to clients or have it done myself. Yet, it seems to be the thing of the day. And all that in my lunch break.
Just imagine, smooth as a baby in six quick, easy and pain-free session.
Just how realistic is it?
Off cause, a full-body treatment is possible. But, does it make sense to do it in one session? To my knowledge, the answer is no. And as usual, I’ll tell you why I think so.
Hair growth cycles.
We all know that hairs have different growth cycles, and therefore we need multiple treatments to get rid of most of them. But, some of us prefer to forget that the hair growth cycles differ over the human body. The average cycles are (remember that this is not set in stone):
- Neck and head: 4 to 6 weeks.
- Body (shoulders to pubic): 7 to 9 weeks.
- Legs and feet: 12 to 14 weeks.
Doing a neck and head treatment every 4 to 6 weeks make sense. Doing a body treatment every 4 to 6 weeks, I can still imagine some logic, not necessary the most effective way of doing it. Doing legs every 4 to 6 weeks?
I have this sneaky feeling that you will have a happy client until treatment 6 is done, and they stop. During the course of treatments, you have shedding after every treatment. This is not difficult, it’s the body’s first reaction when the follicle is heated over 40 °C. Six months after your client stopped, you’re going to have a very unhappy client.
Each and every person that just mention the idea of laser hair removal will get her full opinion of what a scam it is. She paid a fortune and had such little result that she can only advise against it. “And if you’re really going to try it against my advice, I recommend at least that you stay away from …”
Just imagine how much your investment is going to be worth with a reputation like this.
That’s not all… fluence.
Yes, that old fashioned word everyone tries to ditch nowadays. Fluence is the energy spread over a surface, J/cm2. What this means in practice is that you have to apply a minimum amount of energy to every cm2 of area to be treated. This will allow for the hair to heat up and transfer the heat to the surrounding tissue, to kill the dermal papilla. If you do not apply enough energy, you will under heat and the results will be disappointing, or worse. You can cause hair growth stimulation, ending with darker and thicker hair.
Since most lasers on the market now are diode lasers (mainly the less expensive type), you will find that fluence and pulse duration are linked.
You can either work with a lower fluence and higher frequency (pain-free technique) or with a higher fluence and longer pulse duration, stepping technique. If you choose for the pain-free technique, you need to compensate for the reduction in fluence by increasing the time you scan over a given area.
Imagine a row of holes where you want to plant carrots. You can put a carrot plant into every successive hole and close it before you go to the next hole. At the end of the row, you’re done. This is how you can imagine the stepping technique. You treat every cm2 fully at once before you move on to the next cm2. And at the end of the row you know you can go to the next row because this row is completed.
Now, another way of planting your carrots is to put a plant into every third hole and when you reach the end of the row, you’re not done. You have to come back to the beginning of the same row and put a plant in every second hole that is still open. When you reach the end of the row, you’re still not done. You have to go back to the beginning of the same row one last time and put a plant in each of the remaining holes. When you reach the end of the row this time, you’re done planting this row, and you can move on to the next row. This is how you can visualize the gliding (or pain-free) technique.
In laser hair removal, this means that you have to calculate the surface area and the energy required for that area. Next, you have to calculate the time you will need to repeatedly scan the area (row) before you can go on to the next area. The more expensive machines do this for you, the less expensive machines don’t.
If done correctly, the pain-free technique requires more time than the stepping technique. This is because you compensate with time for the lower fluence. If you don’t, you reduce the results of your treatment.
But, let me come back to my lunch break. 75 minutes, I notice this is the magic time it takes for my full-body treatment. Now since I’m a man and have chest and stomach hair, maybe a bit on my back, and you don’t want to see my legs. I imagine that I have a lot to benefit from this.
I’m a skin type 3 with dark hair and will say with average pain tolerance. My stomach and chest is about 38 cm by 45 cm = 1710 cm2. If I’m treated with a 12 mm x 12 mm (1.44 cm2) handpiece it means that I need on this area alone 1188 pulses (1710 / 1.44), at about 25 J/cm2 for a first treatment. Given the Thermal Relaxation Time for hair and the Thermal Damage Time for the dermal papilla, it is best to work at least at 200 ms. I will even recommend 400 ms. This means that you can work at most on 2 Hz. But, I can tell you upfront, my pain tolerance will not allow it. Thus, we’re on 1 Hz.
The actual time the laser pulse is on for this part of my treatment is 8 minutes (1188 pulses x 400 ms). If you add one second skin cooling time per pulse, you add 20 minutes. Thus, 30 minutes – in theory. I can say that I have not done a treatment at this energy level in such a short time (I’ve been doing this now for more than twenty years). Realistically, we will spend about 90 minutes on my chest and stomach treatment alone.
Anyone with experience will know that by this time my pain tolerance has decreased, and my irritation level started to rise.
I don’t have a problem on my back, so we skip and go to my legs. I have about 2500 cm2 per leg, a total of 5000 cm2 for both legs. This is 3 times the surface of my chest and stomach. Going through the same calculation as with my chest and stomach, we end up with 270 minutes, or about 4.5 hours. Off cause, we decided that for a first treatment we can reduce the fluence and work a lot faster, lower it to 2.5 hours.
By this time, the accumulative effect of the treatment lowered my pain tolerance to 0% and increased my irritability to 100%. It is time to stop the treatment.
I still wanted to do my pubic, arms, axilla and just how much easier will life be without this beard…
To conclude.
To watch a sci-fi film (or Chinese training video) where it only takes one stroke of a gentle laser beam to solve all problems, remains an imaginary exercise.
Not respecting the hair growth cycles during a course of treatments, doesn’t improve your results. To the contrary, it diminishes your results. Trying to fit the whole body’s cycles into one session will not work in a treatment course of 6 treatments. If you extend it to a 21 treatment course, it may. But, how do you plan to sell 21 treatment to your client when everyone else promise 6 treatments?
A sensation free treatment guarantees a result free treatment. You need to cause heat at a level in the skin where there are a lot of nerve sensors present. Your client should have some sensation. But, it should remain tolerable to your client.
To generate enough heat, you have to apply a minimum level of energy.
It is not only heat that counts. You also need time for the hair to heat up, spread the heat to the surrounding tissue, and heat the surrounding tissue long enough to kill the dermal papilla. Thus, you require a long pulse duration.
A pain-free hair removal session doesn’t mean a sensation free hair removal session. It means you have the skill to ensure an effective treatment for your client at a certain comfort level. A sensation free treatment does guarantee a result free treatment.
It is normal for the body to shed its hair when the follicle is heated over 40 °C. It sometimes even happen after a severe fever. You will have shedding when you under treat. But, you will have no permanent results.
Think twice about the promises you make to your clients. The person selling you the machine will not take responsibility over from you when your door is lined with unhappy clients. If you’re going to make the investment in equipment, take the time first to educate yourself before you spend the money.
