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Difference between laser treatment and the effect of phototherapy to improve spots and skin quali...



Difference between laser treatment and the effect of light treatment to improve spots and skin quality as a whole

Many people who are suffering from skin problems may have multiple symptoms that they want to improve, such as "I'm worried about spots and pores."

In aesthetic medicine, there are treatments that work on complex skin problems such as age spots, pore openings, and lack of firmness . That is light therapy . Light therapy uses the heat of light to improve skin problems.

Similarly, there is laser treatment as a treatment to improve skin troubles by heat action, and knowing the mechanism of phototherapy, the effect of treatment, and the difference between phototherapy and laser treatment will lead to the selection of treatment that you will not regret. I will.

Characteristics of light emitted by phototherapy

Light treatment is a treatment that aims to improve the overall skin quality by irradiating the skin with special light to improve spots, freckles, pore openings, lack of firmness, etc.

The heat action of light destroys the causes of skin troubles and activates "fibroblasts" that produce collagen and elastin, which give the skin firmness and elasticity, leading to improvement of skin problems . In phototherapy in cosmetology, light called IPL (Intense Pulsed Light) is often used. IPL is a splash lamp that strongly emits instantaneous light like a camera flash, and is light with a wavelength per near-infrared light from visible light from which harmful ultraviolet rays have been removed.

Light is a type of electromagnetic wave

Light and laser are a type of electromagnetic wave, and electromagnetic waves are classified into gamma rays, X-rays, ultraviolet rays, visible rays, infrared rays, microwaves, and high frequencies according to the difference in wavelength.

Light, such as an IPL, contains multiple wavelengths. Wavelength is the length of a wave from peak to peak (or valley to valley) that repeats peaks and valleys, and is expressed in nanometers (nm), which is one billionth of a meter.

The wavelength of sunlight, which is natural light, is about 300 nm to 3000 nm, and the wavelength of visible light that can be seen is about 400 nm to 750 nm. When the wavelength changes, the color of the visible light changes as follows.

purple 380 nm-435 nm
Blue 435 nm-500 nm
green 500nm-570nm
yellow 570nm-590nm
Orange 590 nm-620 nm
red 620 nm-750 nm

Wavelengths shorter than visible light are called ultraviolet rays, and wavelengths longer than visible light are called infrared rays. The wavelength of IPL is about 500 nm to 1200 nm, which corresponds to infrared rays from visible light, and includes multiple wavelengths .

Explanatory image of electromagnetic waves

Unlike light, laser treatment lasers, which are often compared to phototherapy, have a single wavelength, such as the 694nm ruby laser and the 755nm alexandrite laser.

Characteristics of wavelengths contained in light

Generates heat by being absorbed only by a specific substance

Wavelengths have the property of being absorbed only by specific substances, and in cosmetology, the effects of heat and shock waves generated by the absorption of wavelengths are used to improve skin problems.

Since specific substances differ depending on the wavelength, select the required wavelength, such as the wavelength absorbed by the melanin pigment if you want to improve the spots, or the wavelength absorbed by the hemoglobin of the blood if you want to improve the reddish face. Will be done.

Since IPL contains wavelengths that are easily absorbed by melanin pigment, hemoglobin, and water, it can be said that one machine can improve complex skin problems with phototherapy.

Irradiation by cutting unnecessary wavelengths in phototherapy

The phototherapy machine has a filter that cuts unnecessary wavelengths, and you can change the irradiation wavelength by changing the filter depending on the treatment content. For example, to improve blemishes, use a filter to select a wavelength band that is well absorbed by the melanin pigment that causes blemishes .

When a 755 nm filter is used, wavelengths below 754 nm are cut and light with a wavelength of 755 nm to 1200 nm can be irradiated. In other words, the filter cuts wavelengths shorter than that value. Also, the closer the wavelength is to the filter value, the stronger the irradiation.

The effect of phototherapy is to improve spots and redness and improve skin quality.

Light therapy acts on the epidermis and dermis layers of the skin

Skin structure Human skin is layered from the outside with the epidermis layer, dermis layer, and subcutaneous tissue.

In addition, the outermost epidermis layer is divided into four layers from the outside: the stratum corneum, the stratum granulosum, the stratum spinosum, and the basal layer, which is the metabolism of the skin, "turnover". I'm repeating. Turnover is the cycle from when cells are generated in the basal layer to when they are pushed up to the upper layer and become dirt and peel off.

Moderate heat damage to the epidermal layer with light treatment activates turnover .

In addition, the dermis layer below the epidermis layer contains components that play an important role in making the skin firm and elastic. About 70% is collagen, which is a fibrous protein, and collagen is bundled with elastic fibrous protein called elastin. And the space is filled with jelly-like hyaluronic acid that holds water. It is "fibroblasts" that produce this collagen, elastin, and hyaluronic acid.

When fibroblasts are stimulated by the heat of phototherapy, new collagen, elastin, and hyaluronic acid are produced .

In this way, phototherapy can be expected to have the following effects by adding action to the epidermis layer and dermis layer to activate turnover and fibroblasts.

Improvement of spots and freckles

In phototherapy, cells containing melanosomes that store melanin pigment are heat-damaged at wavelengths that respond to the melanin pigment. The turnover activated by phototherapy promotes the excretion of melanin pigment , leading to improvement of age spots and freckles.

Heat-damaged cells form a thin scab-like microcrust and then fall off within a week or two .

Improvement of acne and redness of skin

Acne and redness of the face are manifested by the dilation of the capillaries under the skin that can be seen through the skin. The wavelength that reacts with the red pigment of hemoglobin in phototherapy can be expected to have the effect of constricting capillaries and improving the redness of the skin .

In addition, if you choose a phototherapy machine that irradiates light that has the effect of killing acne bacteria, you can aim for a skin quality that is less likely to cause acne .

Promotes collagen production and improves skin quality

The heat generated by the absorption of the wavelength of phototherapy by water, melanin pigment, and hemoglobin causes changes in the properties of proteins such as collagen and elastin in the dermis layer (protein denaturation). Then, it works to be reconstructed, and in the process, collagen and elastin are newly generated, the skin's firmness and elasticity are restored, fine wrinkles and pore opening are improved, and you can aim for healthy skin with smooth texture. ..

According to a research presentation on the effectiveness of IPL (light) treatment on Asian skin, 97 patients received multiple light treatments using 550 nm and 570 nm IPL at intervals of 2 to 3 weeks. However, although cases of temporary erythema and mild blisters were observed, the results showed that it was effective against pigmentation, telangiectasia, and skin texture after the third treatment [* 1]. Is shown to have been obtained.

[* 1] Photorejuvenation for Asian skin by intense pulsed light: National Library of Medicine

Methods: Ninety-seven patients were treated for photoaging using IPL. The cutoff filters of 550 nm and 570 nm were utilized for three to six treatments at intervals of 2 to 3 weeks. Results: Treatment results were evaluated and rated by both patients and physicians A combined rating of "good" or "excellent" was given to more than 90% of the patients for pigmentation, more than 83% for telangiectasia, at the end of the third treatment based on improvement in pigmentation, telangiectasia, and skin texture. And more than 65% for skin texture. There were some minor complications in four cases: one had erythema that continued to the next day and three had minor blisters leaving no marks.

Those who are suitable for phototherapy

  • I'm worried about spots and freckles
  • Dull skin
  • I want to cure my red face
  • I want to improve the redness of acne
  • I'm worried about slack due to lack of elasticity
  • I have a fine wrinkle
  • I'm worried about the opening of pores
  • I'm worried about wrinkles on the back of my hand

According to a paper investigating hand rejuvenation using standard IPL in Asian patients, 45.3% of 128 Japanese patients (mean age 58.1 years) were "excellent", 14.8% were "good", and 37.5%. It was evaluated as "no change" and 2.3% as "bad" [* 2]. [* 2] Hand rejuvenation using standard Intense Pulsed Light (IPL) in Asian patients

Subjects and Methods: The subjects were 128 Japanese patients (average age 58.1) who had lentigines and wrinkles on the dorsa of both hands, and the wavelength spectra of 560 – 1200 nm and 515 – 1200 nm were applied. In general, the number of treatments was not fixed, and further treatments beyond the first treatment were added only when asked for by the patient. Lentigines were assessed on 4 levels and wrinkles on 3 levels. Results: The results in lentigines were graded “Excellent” in 45.3%, “ Good ”in 14.8%,“ Unchanged ”in 37.5% and“ Bad ”in 2.3% of the patients. Dark-toned lentigines in particular improved after one treatment. On the other hand, the results in wrinkles were graded as“ Effective ”in 25.0%, “Hard to tell” in 39.1% and “Ineffective” in 35.9% of the patients after the first treatment, but there was increased improvement in some cases after multiple treatments.

Difference between light therapy and laser therapy

Light therapy can be expected to improve overall skin quality

Light, unlike lasers, has multiple wavelengths rather than a single wavelength. By that amount, it can be expected to be effective for various symptoms, and by changing the filter, one machine can handle a wide range of complex skin problems.

On the other hand, a laser with a single wavelength narrows down the target that can be targeted, so in order to improve multiple skin problems with the laser alone, it is necessary to change to a machine that responds to each problem and perform the treatment.

Main types of laser wavelength Absorbed skin substances
hemoglobin melanin moisture
KTP laser 532nm
Die laser Around 585nm-595nm
Ruby laser 694nm
Alexandrite laser 755nm
Diode laser Around 810nm to 1450nm 〇 at 1450nm
Nd: YAG (neodymium yag) laser 1064nm
Er: YAG laser 2940nm
Carbon dioxide laser 10600nm

Differences in spot treatment

Phototherapy causes thermal damage and laser treatment destroys

The irradiation time per shot oscillated by phototherapy or laser treatment is called "pulse width", which is in milliseconds (1/1000) seconds, nano (1/1 billion) seconds, and pico (1 trillion minutes). 1) There are seconds, etc., and the pulse width of light is in milliseconds.

The shorter the pulse width, the greater the ability to destroy targets such as melanin pigment. Therefore, in laser treatment with a shorter pulse width than phototherapy, the shock wave of the pico laser or the heat of the Q-switched laser destroys the melanin pigment. To do.

On the other hand, in phototherapy, cells containing melanin pigment are damaged by heat instead of being destroyed, and excretion is promoted by turnover, so the process of excretion of melanin pigment is different from laser treatment.

Light therapy causes less post-inflammatory hyperpigmentation

When laser treatment destroys melanin pigment, there is a high possibility that heat action will spread to the surroundings and cause post-inflammatory hyperpigmentation, but since phototherapy has a weak output, post-inflammatory hyperpigmentation is more likely than laser treatment. It is said that the risk is low.

Light therapy has less downtime

A laser is a collection of the same wavelength, with peaks and valleys of wavelength matching, and it travels straight in one direction with high energy density and high output energy. Since light contains multiple wavelengths and has irregular wavelengths, its output is weaker than that of a laser. The weaker the output and the longer the pulse width, the smaller the effect on the treatment site, so it can be said that the "downtime" for the treatment site to recover to the state before the treatment is shorter for phototherapy.

Light therapy is mildly painful

Light treatment is painful as if it were snapped with a rubber band, but many people can tolerate it and do not need anesthesia . It can be said that even those who are vulnerable to pain with less redness after the treatment can receive it with confidence.

Benefits of phototherapy over laser therapy

Light treatment is not a treatment that destroys the target, so it is common to perform the treatment multiple times. Therefore, it is necessary to receive treatment on a regular basis, but it can be said that by receiving treatment on a regular basis, normal turnover can be maintained and skin problems can be prevented .

Laser treatment has a short pulse width and strong energy, so it is likely to be painful and the treatment site will become a scab, and laser treatment is not preferred in cases where spots and freckles are scattered throughout the face.

On the other hand, phototherapy does not have as great an effect on the skin as laser, so even if a wide range of treatments are performed, the skin will recover quickly after the treatment, and not only spots but also dullness will be improved and the texture of the skin will be smoothed. You can aim to improve the quality of your skin .

IPL treatment Laser treatment
Feature Corresponds to various symptoms such as spots, redness, and open pores Corresponds to one symptom
Treatment interval Multiple times a month Often once
downtime Makeup is possible immediately after the procedure The treatment site needs tape protection
pain Treatment without anesthesia May require anesthesia

Main machines capable of phototherapy

Various types of machines that perform phototherapy have been developed by multiple manufacturers, and the filters that cut wavelengths, the pulse width that oscillates light, and the cooling function are different .

Photofacial M22 (515nm-1200nm)

The Photofacial M22 is a machine developed by LUMENIS of Israel, a pioneer of IPL machines. It is possible to irradiate wavelengths from 515nm to 1200nm, and it is a mechanism to convert and irradiate the optimum wavelength for treatment by using 9 types of filters according to skin problems such as age spots and reddish face that you want to improve.

In addition, it has a cooling function that allows you to irradiate the IPL while cooling the skin, so it is said that you will not feel any pain during the procedure . It is a medical device (approval number: 22500BZX00469000) [* 3] that has been approved by the Ministry of Health, Labor and Welfare, and has also been approved by the FDA (US Food and Drug Administration) [* 4], so the effectiveness of treatment and It can be said that it is an IPL device whose safety has been recognized.

[* 3] Medical device insurance coverage: Ministry of Health, Labor and Welfare

[* 4] 510 (k) Premarket Notification: FDA

Light therapy = photofacial is misunderstood

If you search for phototherapy, you will find many words "photofacial", but "photofacial" does not mean the machine name of phototherapy, but refers to the treatment using the IPL device manufactured by Luminous . Since the trademark is registered and the treatment is a medical practice, photofacial treatment can only be provided by medical institutions such as cosmetology dermatologists and cosmetology clinics.

Machines used in treatments such as "photo facial beauty treatment salon" and "light beauty treatment salon" provided at beauty salons have restrictions on IPL output, so they cannot be expected to be as effective as the IPL treatment received at medical institutions. It is said that.

"Photofacial" and "Photofacial" are registered trademarks of Luminous Japan Co., Ltd.

Photo Silk Plus (500nm-950nm)

The machine developed by DEKA's machine in Italy is Photosilk Plus, which irradiates a wavelength of light called UPL (U-Shape Pulse Light), which is said to have a higher ability to decompose melanin pigments than IPL .

The wavelengths that can be irradiated are 500 nm to 950 nm, and it is said that burns are less likely to occur because the wavelengths above 950 nm are cut to prevent absorption of the skin into water . In addition, it is a medical device that has not obtained regulatory approval in Japan.

Limelight (520nm-1100nm)

The IPL device developed by Cutera in the United States is Limelight. It is an IPL device that a Japanese doctor was involved in the development, and since it can irradiate wavelengths of 520 to 1100 nm, it can be expected to have the effect of improving problems such as dull skin, chloasma, fine wrinkles, and pore opening.

In addition, Limelight is a handpiece developed by Cutera that is attached to the tip of a medical device called Xeo (zero) , and when undergoing treatment, Limelight is attached to Xeo to irradiate IPL. Both Limelight and Xeo are FDA-certified [* 5] [* 6] medical devices.

[* 5] LimeLight IPL Handpiece Medical Device Identification: FDA

[* 6] xeo Laser System Medical Device Identification: FDA

Icon (500nm-670nm, 870nm-1200nm)

The IPL device developed by Cynosure of the United States is an icon, and you can select the wavelength to irradiate by changing the handpiece according to the purpose of treatment, so a wide range of skin problems such as spots and lack of firmness are mainly used. It is a machine that can support. Since it has a function to cool the skin, it is said that you will not feel any pain during the procedure, and you do not need to apply a cooling gel.

The icon is a machine [* 7] approved as a medical device (JMDN code: 70606000) in Japan, and has also been approved by the FDA [* 8].

[* 7] Information provision website for medical device standards, etc .: PMDA

[* 8] 510 (k) Premarket Notification: FDA

I2PL Norris (400nm-950nm)

Nordlys is a machine developed by Ellipse A / S of Denmark and has been approved by the FDA [* 9]. A double filter cuts specific wavelengths that damage the skin and irradiates the IPL with an irradiation method called "I2PL (I2PL)", which enables highly safe treatment. ..

Ellipse was merged into Syneron Candela in the United States in 2018.

[* 9] 510 (k) Premarket Notification: FDA

Cyton BBLs (400nm-1000nm)

It is a phototherapy machine developed by SCITON in the United States and irradiates a wavelength band called broadband light (BBL) . There are seven types of compatible filters, and by using each filter separately, the wavelength suitable for the purpose of treatment such as skin tightening and fine wrinkle treatment is selected and irradiated from the wavelength range of 400 nm to 1000 nm.

In addition, Saiton BBLs are machines [* 10] that are approved as medical devices (JMDN code: 70606000) in Japan, and are managed medical devices (class II) that mean that the risk is relatively low in terms of classification.

[* 10] Information provision website for medical device standards, etc .: PMDA

What you need to know about the risks and side effects of phototherapy

Realize the effect of phototherapy with multiple treatments

Light treatment is performed while finely adjusting the output according to the pain and skin condition. Therefore, some people will see the effect with one treatment, while others will realize the effect with multiple treatments.

Basically, the effect of the treatment tends to increase as the number of treatments increases, and although it depends on the type of skin trouble, it is recommended to perform the treatment about 5 times every 3 to 4 weeks .

If the treatment is interrupted in the middle of the recommended number of times, it will take time to improve the skin troubles and the effect that should be obtained cannot be expected, and there is a possibility of recurrence .

Light treatment may appear to darken the spots

A thin scab called a microcrust may appear on the peak approximately 3 days after irradiation, and the stain may appear darker. This is because the melanin of the spots that have been irradiated with light moves to the upper layers of the skin, and then it peels off in about a week in daily life such as face washing . The microcrust will come off naturally, so don't force it off, and avoid skin care that irritates the skin, such as scrubbing or peeling , for about a week .

Risks, side effects and downtime in phototherapy

Redness and tingling

The spots and the area around the spots may turn red or tingle, but it will settle in a few days at the longest.

If you have a strong tingling sensation, cool it with an ice pack to relieve the symptoms. If it doesn't go away after a few days, some medical institutions may prescribe an ointment or steroid cream to reduce inflammation.


On sunburned skin, dark skin, dark spots and freckled skin, the effects of heat can cause minor burns . If you experience blisters after the procedure, please consult a medical institution.

Post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation occurs when burns occur, but it disappears over time in about 3 to 6 months . In addition, quick improvement can be expected by using topical whitening agents such as tretinoin and hydroquinone.

Aftercare of phototherapy

Immediately after IPL irradiation, the skin is sensitive to UV rays and dryness. No protective tape is required, but it is recommended that you take proper UV protection and moisturize more than usual.

Those who cannot receive IPL treatment

  • Pregnant and lactating
  • Those who have an extreme sunburn
  • Those with a history of epileptic seizures

Those who are above cannot receive the treatment.

Cosmetology menu that goes well with phototherapy

Chemical peeling

Chemical peeling is a procedure that removes sebum and dead skin cells that have clogged pores by applying a drug to the skin and wiping it off.

By removing excess keratin by peeling and then performing phototherapy, the wavelength of light can easily reach the skin, and a higher therapeutic effect can be expected .

Hydra Facial

Similar to chemical peels, Hydra Facial is a peeling machine that can remove dead skin cells and excess sebum from pores. Chemical peels may not be suitable for the skin or may cause dryness or rough skin, but Hydra Facial is minimally irritating and prevents dryness as it not only removes dead skin cells and dirt but also moisturizes at the same time. can do.


Iontophoresis is a procedure that introduces the active ingredient into the skin using a device that conducts weak electricity.

Normally, human skin has a barrier function that prevents foreign substances from entering from the outside, and the ingredients of skin care products such as lotion only have a moisturizing effect on the surface of the skin and do not penetrate deep into the skin.

In the treatment by iontophoresis, if the drug to be introduced is negative, a negative electrode is applied to the skin, and if it is positive, a positive electrode is applied so that the active ingredient repelled by the electrode reaches deep into the skin beyond the barrier function of the skin. is.

By performing it after phototherapy, it supports skin recovery after treatment .

Beauty infusion / beauty injection that you want to use in combination with phototherapy

High-concentration vitamin drip Whitening, antioxidant action, skin collagen production assistance, etc.
Whitening drip (glutathione drip) Whitening, liver function improvement, detoxification, etc.

Oral medicine that you want to use in combination with phototherapy

Cinard Relief of pigmentation due to spots, freckles, rashes, etc.
Tranexamic acid Improvement of chloasma, anti-inflammatory effect of stains, etc.
Yubera Improving blood flow, improving sensitivity to cold, etc.
Sunscreen to drink (supplement) Antioxidant effect, etc.

Topical drug that you want to use with phototherapy

Tranexamic acid lotion Improvement of chloasma, moisturizing effect, whitening, etc.
Hydroquinone cream Decrease in melanocytes (cells that produce melanin pigment), suppression of melanin pigment production, etc.

How to choose a medical institution to receive phototherapy

Light treatment is less burdensome to the skin and works on complex skin problems with a single irradiation, but caution should be exercised when treating spots with overlapping "chloasma" that may be exacerbated by irritation. It is necessary and can cause burns depending on the condition of the skin. Therefore, it may be safe to have a medical institution that cherishes the time of counseling and thoroughly examines skin problems and skin conditions.

In addition, phototherapy may be effective with a single irradiation, but in general, it is a treatment that is effective by repeating the treatment. By performing regular treatments, you can improve the quality of your skin and aim for trouble-free skin. Therefore, it is a good idea to choose a medical institution that will guide you through aftercare .

Light therapy at a medical institution is a medical practice and is performed using a machine that is only allowed to be used by medical qualification holders. There are beauty salons that use similar machines, but there is a big difference in the output of phototherapy at medical institutions between beauty salons and home-use machines that can be operated by beauty salon staff. Under the medical examination of a doctor , aim to improve skin problems at a medical institution that has a menu that can be used in combination with phototherapy by making the most of the power of light while being safe and accurate .

(Updated January 2021)