What is Cold Laser Therapy and How Does It Work?

What is Cold Laser Therapy and How Does It Work?

What is Cold Laser Therapy?

Cold laser therapy, also called low-level laser therapy (LLLT), is an FDA-approved treatment modality that utilizes a non-invasive laser light source that penetrates the skin. 

It is called cold because the low levels of light generated by the device are not enough to heat body tissues. It is referred to as low-level because it uses light at lower energy densities than other forms of laser therapy. The resultant effect of Cold laser therapy is not thermal but photochemical.

This is a painless, sterile, and drug-free therapy that has been used for many years to treat various conditions that cause acute and chronic pain. It can also stimulate healing, improve blood circulation and reduce fat.

Cold laser therapy is known by various other names such as photo biostimulation, soft laser biostimulation, Low emitted diodes (LED) therapy, and Low-power laser therapy (LPLT).

What is the difference between Laser Therapy and Cold Laser Therapy?

Laser (an acronym for Light Amplification by Stimulated Emission of Radiation) is a machine that makes an amplified, single-color source of light. 

It stimulates atoms or molecules to emit light at a particular wavelength. It then amplifies the light, producing narrow beam radiation. This heats up the target tissue which can cut tissues, destroy tumor cells or coagulate tissues.

Cold laser therapy, on the other hand, is a low-intensity laser-based treatment. The non-thermal photons of light generated by the device do not heat the body tissues, nor does it produce any sound or vibrations.

How does Cold Laser Therapy work?

Cold laser therapy is a handheld device the size of a flashlight.  It uses low-level diodes of different wavelengths which are applied to target areas. 

The light passes through the different layers of skin: epidermis, the top layer; the dermis, the middle layer, and subcutaneous tissue, the lowermost fatty layer.

When the light energy passes through the layers of skin, the tissues absorb the light. The laser light interacts with the light-sensitive cellular elements. The light elicits biochemical changes within the cells which are comparable to the process of photosynthesis in plants. 

Similar to how sunlight absorbed by plants is converted into usable energy, cells absorb light energy which triggers a physiological reaction.

Stimulation of specific cellular receptors promotes the production of energy, growth, and proliferation of cells, enhancing biochemical reactions and synthesis of proteins and growth factors. 

The light also causes an increased flow of blood and oxygen to the desired area. This will eventually control inflammation, repair damaged tissues, reduce pain and healing time.

The lights used in cold laser therapy are in the red or near the infrared region of the light spectrum.  These wavelengths can penetrate skin along with hard and soft tissue. These lights have been proven to be effective in many experimental human trials.

Cold laser therapy devices use two lights: one of the wavelengths between 600 and 700 nanometers (nm) and the other between 780 and 950 nm. 600-700 nm light is used to treat superficial tissues. 

Melanin pigments in our skin absorb light of this wavelength very well which inhibits bacterial growth and promotes cellular development. It has incredible results in scar tissue regulation and wound healing.

780-950 nm light increases ATP production in muscles and soft tissues.

What is Cold Laser Therapy used for?

LLLT therapy can stimulate the proliferation of muscles, ligaments, nerves, fibrous tissue, nerve fibers, etc. This can be applicable in a wide range of clinical settings including rheumatology, physiotherapy, dentistry, and dermatology.

Rheumatology and physiotherapy

Cold laser therapy used in musculoskeletal conditions, including chiropractic laser therapy are:

• Osteoarthritis

• Rheumatoid arthritis

• Low back pain

• Disc herniation

• Tendinitis

• Fibromyalgia

• Sports injuries

• Carpal tunnel syndrome

• Nerve pain (Sciatica)

• Temporomandibular disorders

• Shoulder or hip bursitis

• Tennis elbow

• Plantar fasciitis


The application of cold laser therapy in dentistry lies in alleviating dental pain caused by:

• Orthodontic procedures

• Third molar surgery

• Dentine hypersensitivity


Cold laser therapy is used in:

• Acne and related scars

• Burns

• Psoriasis

• Vitiligo

• Rashes

• Dermatitis

• Accelerating healing in skin ulcers

• Stimulating hair regrowth in balding individuals

Other serious diseases

LLLT is being considered for the treatment of serious neurological conditions and degenerative brain diseases such as:

• Stroke

• Spinal cord injury

• Traumatic brain injury

• Degenerative central nervous system disease

• Parkinson’s disease

• Alzheimer’s disease

• Amyotrophic lateral sclerosis (ALS)

Veterinary medicine

Veterinary conditions that are treated include:

• Acute and Chronic Otitis

• Degenerative disc disease

• Anal glands

• Gingivitis and periodontal disease

• Arthritis

• Lick granulomas

• Hip dysplasia

• Hot spots and other dermatological disorders

How to use Cold Laser Therapy?

Cold laser therapy is being used by doctors, physiotherapists, dentists, chiropractors, veterinarians, and pedicurists. The handheld laser device is pointed at the skin where the treatment is required. The device will be very close to your skin or will touch it. The cold laser therapy device will send quick pulses into the target area that typically lasts between 30 to 60 seconds.

Can you use Cold Laser Therapy at home?

Yes, cold laser therapy devices can be used at home, and home-use devices are readily available. These devices have wavelengths from 600 to 890 nm. They are easy to use, portable and convenient. You can use these devices while you are traveling or on animals. Even the elderly who are not comfortable with newer technologies can manage using them.

Some of the best cold laser therapy devices are FDA-approved, have a long-lasting battery, are rechargeable, light-weight with a variety of time and power settings.

How often can you use Cold Laser Therapy?

Cold laser therapy requires more than one treatment session to get the desired results. It can take as little as 8 to a maximum of 30 treatment sessions. You will need 2 to 4 sessions per week.

What are the benefits of Cold Laser Therapy?

• Cold laser therapy is regarded as a gentle and painless procedure.

• One of the main cold laser therapy benefits is that it is a non-invasive procedure. It does not require a surgical incision nor does it need a prolonged recovery time.

• It is a safe procedure when performed under the care of qualified medical personnel.

• It is also a drug-free therapy so there are no hassles of taking medications daily.

What are the disadvantages of Cold Laser Therapy?

There are only a few disadvantages of cold laser therapy. They are:

• Cold laser therapies are not covered by health insurance.

• Requires multiple sessions (as many as four treatments per week) before you can gauge its effectiveness. Patients typically do not get relief from their symptoms at the first session.

• Old injuries may be aggravated for a few days. This is, however, temporary and lasts only a couple of days.

How long does Cold Laser Therapy last?

Most sessions of cold laser therapy typically last as little as 3-5 minutes to as long as 20 minutes. The duration depends upon many factors that will be evaluated by your service provider. 8-15 sessions are required to experience its benefits, sometimes with many as four treatments in a week.

Do I need any preparation for the therapy?

There are no preparations that are required to undergo cold laser therapy. You can get back to your daily activities right after the procedure.

What are the side effects of laser therapy?

Cold laser therapy is generally regarded as a safe procedure. However, it is not without some adverse effects. Some of the infrequently encountered cold laser therapy side effects are:

• Bleeding

• Scarring

• Pain

• Skin color changes

• Infection

Am I a good candidate for cold laser therapy?

You may be a good candidate for cold laser therapy if:

• You have persistent or nagging musculoskeletal pain that is not improving with conventional treatment modalities.

• You suffer from discomfort or pain from previous surgery.

• You have a stubbornly non-healing wound that is bothering you.

• You are in good general health, apart from the condition that you are seeking cold laser therapy treatment for.

• You are looking for a non-invasive, painless method for improving your chronic pain or wound healing problem.

When should I not use Cold Laser Therapy?

Some contraindications of the use of cold laser therapy are:

• Pregnancy

• Children

• Cancer or areas suspicious of cancer

• Use in thyroid or eyes

• Use in epileptics

How much does Cold Laser Therapy cost?

The cost depends upon the size and power of the laser. It also depends on the specific treatment needed, wavelength, and the desired treatment outcomes.

The price of a cold laser therapy device varies depending upon the wavelength, various settings, additional tools, and size. The cost may vary from 500 to 5000 USD.

The bottom line

Cold laser therapy is a non-invasive treatment modality that can potentially provide relief from chronic pain without the use of surgery or medication. It is a new alternative treatment concept that has wide clinical applications in rheumatology, physiotherapy, chiropractic medicine, dermatology, neurology, and even veterinary medicine. It can be used alone or in combination with other treatment options.


• Cotler, Howard B et al. “The Use of Low Level Laser Therapy (LLLT) For Musculoskeletal Pain.” MOJ orthopedics & rheumatology vol. 2,5 (2015): 00068

• Dima, Robert et al. “Review of Literature on Low-level Laser Therapy Benefits for Nonpharmacological Pain Control in Chronic Pain and Osteoarthritis.” Alternative therapies in health and medicine vol. 24,5 (2018): 8-10.

• Saghaei Bagheri, Hesam et al. “Low-Level Laser Irradiation Modulated Viability of Normal and Tumor Human Lymphocytes In Vitro.” Journal of lasers in medical sciences vol. 11,2 (2020): 174-180.

• Chung, Hoon et al. “The nuts and bolts of low-level laser (light) therapy.” Annals of biomedical engineering vol. 40,2 (2012): 516-33. 

• Safdari, Roya et al. “The Impacts of Low-Level Laser Therapy - A Complementary Treatment in the Management of Side Effects After Implant Surgery.” Journal of lasers in medical sciences vol. 9,3 (2018): 207-211.