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Can Laser Hair Growth Caps Really Regrow Hair? Evidence Review
Dr Meena Zareie (GMC)
Medically reviewed by
Dr Meena Zareie (GMC)
Updated on February 13, 2024

The hair growth industry is unfortunately flooded with ineffective, unproven products and treatments which promise to magically cure your hair loss. So it is natural to wonder whether laser hair growth caps can really help regrow your hair. While effectiveness largely depends on the type of product you choose, you will be happy to know that the kind of treatment they provide, red light therapy for hair growth, has scientifically proven benefits [1]. 

Research shows that this type of low-level laser therapy (LLLT) can be beneficial in increasing hair density for several types of alopecia, such as androgenetic alopecia [1][2][3], alopecia areata or chronic telogen effluvium [4][5]. Caps are only one of many kinds of devices that incorporate this technology, such as helmets, combs, or headbands. Studies performed on laser hair growth caps show they can be as effective as other LLLT home treatment devices, provided the necessary specifications are respected [1]. 

However, that does not mean that any kind of hair loss can be treated with a laser hair growth cap. So if your hair is falling out, it is important to see a trichologist to get an accurate diagnosis and personalised treatment recommendations.  

Keep reading to find out all you need to know about:

  • How these products work to stimulate hair growth
  • How effective laser hair growth caps are against alopecia
  • The best way to use laser hair growth caps
  • How to choose an effective laser hair growth cap
  • Hair loss treatment alternatives to laser hair growth caps
Table of Contents
red laser cap

What are laser hair growth caps?

Laser hair growth caps are red light home therapy devices. That means that they may look like a regular baseball cap on the outside, but on the inside, they are lined with diodes which emit light in a red or near-infrared range, which penetrates your scalp.

While there are other types of red light home therapy devices as well – such as helmets, combs or headbands [1], many people opt for caps. That is because they are light, discreet, comfortable and easy to use and their shape makes it easy for light to reach the entirety of your scalp at once. 

Do laser hair growth caps really work for hair loss?

Yes, there is evidence that shows laser hair growth caps can be beneficial against certain kinds of hair loss, as long as they are built according to quality standards. That is because they are essentially portable red light therapy devices. This therapy has shown promising results stimulating hair growth in mild to moderate forms of androgenetic alopecia (for both male pattern baldness and female pattern baldness) [1][2][3], alopecia areata and chronic telogen effluvium [4][5].

One study performed on 44 women with female pattern baldness who used a commercially available laser hair growth cap for 30 minutes every other day over 17 weeks revealed a 51% increase in their hair count [3].   

A similar study conducted on 44 men with male pattern baldness revealed a 35%  increase in hair density after 60 sessions with a red light therapy helmet [6]. 

These findings were confirmed by a clinical trial performed on 40 subjects of both genders with androgenetic alopecia [2]. 

before and 24 weeks after red light therapy
Before and after 24 weeks of red light therapy [2]

However, if your hair loss is too advanced or if you are experiencing a kind of scarring alopecia, such as lichen planopilaris or discoid lupus, it is unlikely that laser hair growth caps will be effective in improving your hair shedding without any other treatment.  

informational graphic showing where red light penetrates on the scalp

How do laser hair growth caps work?

Red light therapy is a form of low-level laser therapy that uses focused beams of red or near-infrared light to enhance your cell metabolism and dilate the blood vessels in your scalp, stimulating blood flow to your hair follicles [7]. Moreover, this kind of light is absorbed by an enzyme called cytochrome c oxidase, activating it.

The enzyme plays a role in enhancing the efficiency of the mitochondria (the energy-producing stations of the cell), which, in turn, improves overall cell function. The increased amount of energy and nutrients hair follicles receive helps them remain in the hair growth phase for longer, stimulating natural hair growth and preventing premature hair shedding.

woman showing off the inside of a red laser hair growth cap

How to choose the best laser cap for hair growth

There are several things to look out for when choosing a laser cap for hair growth, to increase your chances of purchasing a safe and effective device:

Wavelength range

The normal range of red light is between 630-750 nanometers, while near-infrared light ranges between 810-850 nanometers. However, cytochrome c oxidase, the enzyme that is activated by this therapy, absorbs the most red light at 660 nanometers. So it is best to make sure that the light produced by the device you are planning to buy emits at this wavelength for optimum results, as not all light frequencies are effective at stimulating hair growth.  

Light intensity

Laser hair growth caps normally contain 2 types of light sources: light-emitting diodes (LEDs) and laser diodes (LDs). LDs have been demonstrated to emit light of much higher intensity than LEDs, which makes them more effective. The therapeutic range to look for in a laser hair growth cap is 2-4 joules/cm² [1].

While a device with more LDs generates a greater intensity than one with fewer ones, exposure duration is also important, so you may need to use a lower-intensity device for longer sessions than a higher-intensity one.   

User-friendly features

Programmable timers, adjustable intensity settings, a comfortable and intuitive design and a clear visual interface are only some of the helpful features that make a laser hair growth cap user-friendly. Be sure to compare what each of your main product options has to offer.

Customer reviews

It is generally a good idea to do some research and read other users’ reviews before settling on the laser hair growth cap that best suits your needs. This will not only give you an idea about how satisfied other users are with their achieved hair growth, but it will also help you discover hidden flaws or inconveniences in product design. 

Seller reputation

Make sure that any home therapy device you purchase comes from a reputable seller and a brand you are familiar with. Avoid purchasing used devices from strangers or buying your laser cap from an obscure brand. While you don’t need to get the most expensive product on the market, it is safe to be sceptical of prices that sound too good to be true. 

man taking off his red laser hair growth cap

How do you use a laser cap for hair growth?

It is quite simple to use most laser caps for hair growth. While there can be some variations, according to brand specifications, in most cases, all you need to do is:

  1. Make sure the portable battery is fully charged.
  2. Place the cap on your head.
  3. Connect the cap to the battery, then place the battery in your pocket, your bag or attach it to your belt.
  4. Turn the cap on and let it work. Different brands recommend that you keep the cap on for various amounts of time, depending on the technology and power they use. Generally, it is good to undergo 10-30 minutes of red light exposure from a home therapy device 3-5 times a week for 3-6 months to achieve hair growth.
  5. Gently wipe the inside of the cap down with a damp cloth or alcohol wipe and store it in a clean, dry place. 

Do laser hair growth caps have side effects?

Red light therapy has virtually no significant adverse side effects. If you are using an authentic device, you should be experiencing no pain or damage to your scalp. The light the laser cap emits is not hot, so you are in no danger of getting burned. 

However, some minor side effects may occur from the device itself. If it does not rest comfortably on your head, it may cause mild chafing, itching or tenderness on your scalp. Moreover, if it has been shared and/or has not been properly cleaned between uses, it may carry bacteria that could cause scalp acne. 

Man using minoxidil on bald scalp to treat hair loss

Treatments that can be used alongside laser hair growth caps to curb hair loss

There are several effective hair growth treatments that you can use alongside (or as alternatives to)laser hair growth caps to improve your hair loss. The most effective are:

  • Minoxidil – this versatile treatment is recommended for many types of alopecia. It is usually applied topically on your scalp and works by dilating your blood vessels, allowing more oxygen and nutrients to reach your hair follicles. A review of 15 studies, with 1172 patients in total, revealed that combining red light therapy with Minoxidil or Finasteride yields better results than any of these treatments can achieve on its own [8]. 
  • Finasteride – one of the most recommended medications for androgenetic alopecia, Finasteride is highly effective at preventing male pattern baldness. While it can also sometimes be prescribed for female pattern baldness, it is usually not recommended for premenopausal women.
  • Steroid creams – this treatment is often used to improve the symptoms of alopecia areata, but also to provide relief to patients with scalp psoriasis or eczema. 
  • Dermarolling for hair growth – a therapy that involves making microscopic punctures in your scalp using a small tool called a derma roller. This triggers the body’s natural healing process and at the same time, improves the penetration of topical medication applied on the scalp. 
  • A hair transplant – hair restoration surgery is a simple, effective and mostly painless procedure. It involves harvesting healthy hair follicles from an area on your scalp where you have a sufficient amount (e.g. the back or sides of your head) and reimplanting them in areas where your hair is falling out. It can work very well to fix a messed up hairline, correct frontal balding or cover a bald spot on the crown. And unlike other treatments, a hair transplant is permanent. That means that if you choose to get a natural-looking hair transplant today, you may be able to enjoy fuller, youthful-looking tresses for decades to come. 

Are you concerned about hair loss?

If you are experiencing hair loss, the best thing you can do is to book a consultation with a trichologist for the first signs of hair thinning and balding. That is because certain types of alopecia are progressive, which means they can get worse if they are not properly treated.

While laser caps can help achieve some hair growth, they are not effective against every scalp condition and will likely not be much help against advanced hair loss.

However, a trichologist will examine you, perform all the necessary tests, such as a dermoscopy or a scalp biopsy and recommend the best, personalised treatment for your hair loss. Whether that may involve a laser hair growth cap or a different kind of treatment, you can rest assured that your hair will be in the best hands.

Can Laser Hair Growth Caps Really Regrow Hair? Evidence Review, Wimpole Clinic

Dr Meena Zareie (GMC)
Medically reviewed by Dr Meena Zareie (GMC)Updated on February 13, 2024
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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