Blog Science What’s Beneath the Skin? The Science of 5 At-Home Skin Therapies 
What’s Beneath the Skin? The Science of 5 At-Home Skin Therapies 
What’s Beneath the Skin? The Science of 5 At-Home Skin Therapies 

Authors: Therabody Scientists: Tim Roberts, MSc; Rachelle Reed, PhD, MS, ACSM-EP; Kyle Silvey, PhD, CSCS; Michelle Darian, MS, MPH, RD, LDN 

Your skin is more than just a protective barrier — it’s a complex organ with numerous vital functions. As we face increasing environmental stressors and the natural effects of aging, traditional skincare routines may not address all skin concerns.  

Fortunately, advancements in skincare technology have brought professional-grade therapies into our homes. From light-based treatments to temperature and vibration therapies, these innovative approaches target skin cells and tissue at a deeper level.  

In this article, we’ll explore the science behind your skin’s functions and delve into well-researched therapies — red, infrared, and blue light, cold and heat therapy, and vibration therapy — revolutionizing at-home skincare routines. 

What Are the Skin’s Main Functions?  

The skin is the largest organ in the body. It’s made up of water, protein, fat, and minerals. The skin is primarily composed of three layers: the epidermis, dermis, and subcutaneous tissue: [1

  1. Epidermis: The outermost layer of the skin that protects from water and the environment. 
  2. Dermis: Located beneath the epidermis, this layer contains blood vessels, hair follicles, sweat glands, and more. 
  3. Subcutaneous Tissue: Also called the hypodermis, this is made of fat and connective tissue. 

Together, the three layers of the skin perform several crucial functions: [1

  1. Protection: The skin acts as the body’s first physical barrier against the external environment. It shields against microorganisms, dehydration, and ultraviolet light. 
  2. Sensation: When you touch something, the skin detects it, and the nerves start interpreting it. This includes pain, temperature, touch, and pressure. 
  3. Mobility: The skin allows smooth movement of the body. 
  4. Endocrine Activity: You may have heard that spending time in the sun helps to increase your vitamin D levels. The skin initiates the biochemical processes involved in vitamin D production, enhancing calcium absorption and maintaining bone health (in addition to several other functions like immune and heart health, sleep, aging, and more). 
  5. Exocrine Activity: The skin produces and releases various substances, including oils (sebum), sweat, and chemical messengers. This helps protect the skin, regulate body temperature, maintain fluid balance, and more. 
  6. Immunity: The skin helps defend against pathogens, contributing to overall immune health. 
  7. Temperature Regulation: The skin regulates body temperature through several mechanisms, including conserving or releasing heat. It helps to maintain a proper core body temperature and contributes to overall functioning. 

Now that we’ve explored the skin’s multifaceted functions, let’s discuss how popular therapies help to improve and maintain it. Five treatments have been making waves in skincare, and for good reason: red and infrared light, blue light, heat, and cold therapies. These aren’t just trendy spa offerings — they’re supported by scientific research to impact skin health by leveraging the skin’s natural properties and functions. Let’s dive into the science of how each of these therapies works. 

1. Red & Infrared Light Therapy for Fine Lines and Wrinkles 

Light therapy in skincare has exploded in popularity as this technology is now available at home. These handheld devices deliver light to specific areas of the skin for short periods or through a mask that covers the entire face at one time. These devices use light-emitting diodes, or LEDs, that produce various wavelengths of light to stimulate the skin — including the dermis and epidermis. [2, 3

Red light, the longest wavelength of visible light, ranges from 620 to 750 nm and can penetrate through the skin and target your cells.  

Red light targets fine lines by increasing collagen production. Collagen is a structural protein that helps maintain the skin’s firmness and elasticity. When collagen production declines (a process that happens naturally with age), your skin loses some of its integrity, and fine lines can form.  

Collagen production naturally starts decreasing in your 20s and accelerates after 40, resulting in thinner and less elastic skin. Environmental factors like sun damage can then accelerate this process. [4

Red light therapy can support your body’s natural collagen production. Specifically, red light’s wavelength targets the cells’ energy-producing mitochondria in a process called photobiomodulation — increasing energy production. This fuels cellular repair processes, skin rejuvenation, and collagen production. [5

Red light also targets collagen synthesis more directly by stimulating fibroblasts, the cells responsible for collagen production. [3] It can also be anti-inflammatory, creating a more favorable environment beneath the skin for collagen production and skin repair. 

Devices often pair red light therapy with infrared light therapy for even more benefits. Infrared light has a longer wavelength than red light therapy (around 830 nm) and can penetrate even deeper into the skin. This high wavelength isn’t visible to the eye — but you can feel it. Infrared light therapy creates a warming sensation on the skin, increasing blood flow to the treatment area. [5

Dr. Neera Nathan, MD, MSHS, Harvard-trained medical and cosmetic dermatologist and fellowship-trained Mohs micrographic surgeon, and Therabody Scientific Advisory Board Member weighs in on how red and infrared light therapies have real benefits to the skin. “By combining red and infrared light, you’re getting to different layers of the skin to maximize benefits. Red and infrared LED light in general have been shown to improve skin wrinkles and texture, and can improve skin elasticity and firmness." 

Research shows that when used together, red light and infrared light therapy can: [5,6

  • Improve skin tone 
  • Support collagen production 
  • Reduce the appearance of fine lines and wrinkles 

Light therapy is most popularly used on the face — yet red light and infrared light therapy can also be applied to the muscle. There, it stimulates blood flow and can help reduce stiffness and soreness. [7

2. Blue Light Therapy for Acne 

On the shorter side of the light spectrum is blue light therapy. This shorter wavelength (about 415 to 450 nm) doesn’t penetrate the skin like red and infrared light but can target its surface. Blue light therapy is recognized for its ability to target the acne-causing bacteria that live on the face. [8

Acne is a common (and rather persistent) condition that can result from many factors, including bacteria build-up. Having too much bacteria on the face can clog pores. This causes substances to build up and a pimple to form. [9

Blue light can reduce active acne because, at this wavelength, blue light is absorbed by the acne-forming compound that bacteria produce, called porphyrins. Once porphyrins absorb blue light over several days, they release a single oxygen molecule, killing the bacteria and effectively reducing acne. [10

Studies show that blue light therapy is beneficial in reducing acne. A study found that using blue light therapy for 4 weeks effectively reduced both blackheads and whiteheads. [10

A 2021 meta-analysis combined results from 8 trials and found that blue light did help treat acne, specifically improving the presence of inflammatory lesions. Further, the authors suggested that blue light therapy was generally well tolerated, making it an option for those with acne. [8

According to Dr. Nathan, “Blue light is a go-to for acne. Blue light may be anti-inflammatory, meaning it may decrease inflammation, and it may also have some benefits just by reducing some bacteria on the skin." 

It’s important to note that blue light isn’t recommended for everyone. “I do caution people about blue light because it can exacerbate pigmentation. A full-face light treat can make melasma, hyperpigmentation, or acne marks worse," says Dr. Nathan. Consult with a board-certified dermatologist to determine if light therapy is right for you.  

Blue light therapy is delivered through devices similar to red light therapy. Some technology will have red, infrared, and blue light therapy available within the same device.  

3. Cold Therapy for Depuffing 

Cold therapy, also known as cryotherapy, involves cooling the skin and lowering the temperature of surrounding tissues. It is traditionally used to control inflammation and swelling, such as a rolled ankle, but it can also be used on the face.  

Cooling helps reduce inflammation by narrowing blood vessels and decreasing blood flow to the treated area. This same logic can be applied to the skin to manage puffy eyes and facial swelling. In fact, the American Academy of Ophthalmology recommends using a cold compress to help reduce under-eye bags. [11, 12, 13

Cold therapy’s ability to limit blood flow to the area can help reduce puffiness and tighten the skin. Plus, it feels soothing.   

Dr. Nathan explains, “Overall, cold therapy is really excellent because it constricts blood vessels. When you constrict blood vessels, that leaky fluid that causes puffiness or lymph gets removed." 

Ideally, cold therapy for the face is localized and delivered at a safe and consistent temperature. Ice rollers (often stored in the freezer) are commonly used directly on the face. However, the temperature of these tools is inconsistent — starting off dangerously cold and dropping. The ideal temperature for cold therapy hovers between 45°F and about 59°F (and never below 32°F, which is what most freezers are set at). [14]   

Dr. Nathan cautions that using very cold temperatures on the skin can actually burn the face. “Certain temperatures can be therapeutic, and at a different temperature, it can be harmful." 

So instead, opt for devices that effectively deliver cold therapy at a safe temperature to your face.   

For those looking to depuff in a soothing treatment, add a cooling and temperature-controlled form of cold therapy into your routine.  

4. Heat Therapy for Increasing Circulation and Reducing Tension and Pain 

On the other end of the temperature spectrum is heat therapy, also known as thermotherapy, when something warm is applied to a surface on the body. As with infrared light therapy, heat therapy warms the skin, increases the temperature of surrounding tissues, and increases blood flow and circulation to the treatment area. [15]  

The heat also helps open pores up, allowing for better absorption of topicals. It also stimulates fibroblasts to enhance collagen production to further target skin tightness and fine lines. [15, 16

A good old-fashioned heating pad may not be a safe choice for your face. Instead, look for face-specific devices that deliver safe and consistent temperatures to skin.  

5. Vibration Therapy for Facial Wrinkles and Pain 

Vibration therapy uses mechanical vibrations that contact the skin and stimulate different receptors in both the skin and the tissue below it. These rapid oscillations have been shown to reduce pain, improve skin blood flow, and reduce inflammation. [17, 18, 19

This therapy works by stimulating short-term blood flow. [20] In fact, combining heat and vibration therapy stimulates short-term blood flow to a greater extent than either alone. [21]  

The gentle, rhythmic vibrations have been shown to increase elastin and collagen and improve sagging. [22] Furthermore, they have been shown to improve the appearance of facial wrinkles and skin texture when combined with topical skincare. The vibrations enhance the absorption of skincare products, making them more effective. [23]  

Research indicates that applying vibration therapy to a treatment area may help reduce pain perception. Vibration may offer relief for conditions like temporomandibular disorders (TMD), particularly TMJ (facial joint) pain. [24]  

When choosing a vibration therapy device, look for one with adjustable intensity stories designed for facial skin. 

*This article provides general information and discussions about health and related subjects. The information provided in this article and any linked materials are not intended for and should not be construed as medical advice, nor is the information a substitute for professional medical advice, diagnosis, or treatment. 

Key Takeaways 

  • The skin is the body’s largest organ, assisting with vital functions such as protection, temperature regulation, and immunity. 
  • Taking care of your skin means taking care of the tissues and cells that make it up.   
  • Red and infrared light therapy can stimulate collagen production and reduce fine lines and wrinkles. 
  • Blue light therapy targets acne-causing bacteria, helping to reduce breakouts. 
  • Cold therapy can help reduce puffiness by temporarily constricting blood vessels and decreasing inflammation. 
  • Heat therapy temporarily increases circulation, opens pores, and may enhance the absorption of skincare products. 
  • Vibration therapy may help improve wrinkles and relieve facial pain.  
  • Many devices on the market combine these therapies into one device, allowing you to take advantage of treatments back-to-back or as your concerns shift over the weeks, months, or years.   

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