Q-switch lasers use a “Q-switched” technique to emit tight pulses of concentrated photons (light energy). The laser beam is powerful enough to penetrate deep into the skin yet gentle enough to treat the face. The FDA considers the Q-switch laser safe and effective for its intended uses.
This article reviews the various types and uses of the Q-switched laser. It discusses how Q-switch lasers work for tattoo removal and addresses the side effects associated with Q-switch laser procedures elsewhere on the body.
Uses
The Q-switched laser serves many purposes in cosmetic dermatology.
Since it is non-ablative, the Q-switch laser can heat deeper layers of skin without damaging or scarring skin tissues. This makes it a valuable tool in skin resurfacing (i.e. wrinkle reduction), not to mention its various medical uses.
Tattoo Removal
Q-switch lasers come in different wavelengths. Lasers with 1064 nanometer (nm) wavelengths are used to remove dark blue or black tattoos, while those with 532 nm wavelengths can remove red, sky blue, and green colors.
Q-switch lasers remove tattoos by penetrating into the skin then heating tattoo ink until it shatters. The ink is then filtered out of the body through the lymphatic system.
When used correctly, Q-switch lasers break down tattoo ink without damaging or scarring the surrounding skin.
For one 2015 study, 12 blue or black tattoos were each treated three times with a 1064 nm wavelength Q-switched laser. The improvements were significant, although none of the tattoos were completely gone after three sessions.
The report also mentions that the most significant improvements were seen in tattoos that were done at least 10 years before.
Skin and Vascular Lesions
Q-switched lasers can be used to treat pigmented skin lesions and vascular (vein) lesions, including but not limited to:
Nevus of Ota is hyperpigmentation on the face and sometimes in the eye, usually on just one side. In 2014, researchers noted excellent improvements in nevus of Ota following Q-switch laser removal. No adverse side effects were reported and little to no recovery time was needed.
Lentigines are flat, hyper-pigmented spots caused by sun exposure or aging skin. Q-switched lasers are effective for gradually reducing them but come with a risk of increased hyperpigmentation, particularly in darker skin types. A 2016 study showed significant improvements in lentigines after just one Q-switched laser session.
Melasma is a condition in which hyper-pigmented spots or patches form, typically on the face. Studies show that Q-switched laser treatments can fade them substantially within three, once-per-month treatments. Only mild, temporary side effects like itching have been reported.
Cafe-au-lait are flat patches of hyper-pigmented skin seen on newborn infants. For a 2019 study in China, cafe-au-lait spots in 471 children were treated with Q-switch lasers. An overall success rate of 79% was reported for cafe-au-lait removal with no adverse side effects reported.
Spider angioma are sometimes called spider veins due to their red or purple spider-like appearance. Spider angiomas are caused by dilated (widened) blood vessels near the surface of your skin. Q-switch lasers have been used to reduce spider angiomas in the face and neck with favorable results.
Skin Rejuvenation
Laser liposuction is a non-invasive alternative to liposuction with little to no recovery time. Q-switched lasers are widely used in laser liposuction, as they can effectively reduce unwanted fat while minimizing tissue damage. One 2014 study found that Q-switched laser liposuction resulted in 54% less blood loss compared to traditional liposuction.
Acne scars can be effectively treated with a Q-switched laser. A 2022 study published in the journal Medicina showed significant acne scar improvements within three, 1064 nm Q-switch laser treatments, done every eight weeks. No significant side effects were reported. The Q-switch treatments were regarded as safe and effective.
Skin resurfacing procedures are commonly done using Q-switched lasers. Treatments aim to improve skin tone and texture, diminish wrinkles, and reduce the skin’s oil production. A study published in 2022 found that Q-switch laser treatments substantially reduced dark circles and wrinkles under the eyes within six treatments.
How Q-Switch Lasers Work
There are several different brands of Q-switched lasers, including the Q-switched Nd:YAG lasers, Q-switched Ruby lasers, Q-switched Alexandrite lasers, and Picosecond Alexandrite lasers.
Q-switched lasers are available in different wavelengths. In terms of tattoo removals and hyperpigmentation, Q-switched lasers with wavelengths of 1064 nm and 532 nm are most beneficial. Longer wavelengths penetrate deeper into the skin.
For example, since black tattoo ink is deposited into the epidermis (second) layer of skin, a 1064 nm wavelength is needed to remove it. Freckles, on the other hand, are a build up of melanin in the skin’s dermal (first) layer of skin, so a 532 nm laser is better suited to treat them.
Unlike other types of common lasers that emit one continuous laser beam, Q-switched lasers emit brief pulses of more condensed light energy with a uniform wavelength. The advantage of this is that it allows for more precision while minimizing heat build-up and tissue damage under the skin.
Tattoo Removal
Laser tattoo removal is the only method proven to remove tattoos without scarring. To remove a tattoo, the Q-switched laser is pulsed over it, directing its light energy towards the ink. The energy is absorbed by the ink particles, which then shatter into tiny fragments.
In the days following the laser procedure, the body’s immune system absorbs the ink particles through the lymphatic system, which are then filtered out of your body. Following the procedure, the tattoo will gradually fade over the coming weeks.
Laser treatments are typically done every six weeks. Depending upon the size and color of the tattoo, multiple sessions may be needed, sometimes up to twenty. This can depend on the tattoo’s colors, the type of ink that was used, when the tattoo was done, and more.
Many times, tattoos are unable to be removed completely. In particular, multi-colored and layered tattoos, such as tattoo cover ups, may be more difficult to remove.
Hyperpigmentation
Hyperpigmentation occurs when there is an excess production of melanin, the natural pigment in skin, hair, and nails. Melanin is produced in the skin’s epidermis (second layer), where collagen is produced.
Q-switch lasers reduce hyperpigmentation in a similar way that they do tattoos. The Q-switch laser directs light energy into the epidermis, shattering excess pigmentation. The excess melanin is then absorbed by the lymphatic system and filtered from the body.
In the days and weeks after a Q-switch laser skin treatment, the treated skin will get to work producing collagen, helping skin cells to repair the skin as the tattoo fades.
Before Treatment
Consultations with a healthcare provider or dermatologist are typically required before a laser procedure. During your consultation, your provider may:
Evaluate your skin type and general health statusAsk about your skin care regimeAsk about your medications or allergies, if anyAsk what you want to achieve from your procedureDiscuss your optionsRecommend a course of treatmentProvide an estimate for the number of laser sessions needed
The consultation is a great time to ask questions.
Whether you choose to follow through with a procedure after your consultation is entirely up to you. In some cases your provider may be able to perform the procedure within the same day. Other times, you may need to book for a later date.
In the lead up to your procedure, your provider may ask you to avoid using scrubs, exfoliants, bleaching creams, or retinoids on the skin area being treated. They may also ask you to avoid the sun.
Treatment Day
Your provider may or may not have you wear a medical gown. They may apply a numbing cream or local anesthetic to your skin before the procedure begins. You will also be given eye shields to protect your eyes.
For Q-switched laser treatments, providers should do a ’test spot’ on the skin to ensure the laser and its settings are compatible with your skin type.
Q-switched laser treatments can take anywhere from 10 to 45 minutes, depending on the procedure and how big or layered the treatment area is.
Afterwards, you may be given the option to schedule your next laser treatment, if needed. There should be at least six to eight weeks between each laser session.
Recovery
Once your Q-switched laser treatment is finished, your provider will cover the treated area in a sterile bandage. Your provider may ask you to:
Keep the treated area covered for 24 to 48 hoursAvoid soaking the skin area in water Avoid direct sunlightAvoid touching, itching, or picking at the treated area
You may need to apply an antibiotic or antiseptic ointment to the treated area and keep it covered for 7 to 10 days.
Q Switch Laser Safety
Q-switched laser technology is widely regarded as safe and effective. In addition, studies have found high levels of patient satisfaction following Q-switched laser treatments.
One such study from 2022 evaluated the safety and efficacy of a 1064 nm Q-switched laser for treating dark circles and wrinkles under the eyes.
Before and after photos show Q-switched laser treatments resulted in clear reductions in wrinkles and melanin. The only side effects reported were mild irritation and redness, lasting just a few days post-procedure.
Possible Side Effects
Side effects after Q-switched laser treatments are uncommon but can include:
Hyperpigmentation, sometimes due to inflammation or having laser treatments too close togetherA low risk of scarringRarely, an allergic reaction to fragmented tattoo inkSwelling and bruisingItching
Contact your healthcare provider right away if you develop blisters or signs of infection.
Summary
Q-switched lasers are a commonly used laser to help treat many skin conditions, from pigment changes to tattoo removal. The type of laser and the wavelength given is dependent upon each person and the reason they are having laser treatment.
A Word From Verywell
Q-switched laser therapy can be an effective treatment for your skin condition or tattoo removal. Whatever the reason, be sure to ask your healthcare provider about any questions you may have about the procedure, and any special instructions you need to follow to get the best outcome.
