Red Light Therapy For Hair Growth: Worth The Hype!

I'm getting these questions all the time:

• "What does red light therapy do for hair?"
• "What are the red light therapy benefits for hair growth?"
• "And how effective is red light therapy for hair growth?"

I'll answer all these questions in my red light therapy for hair growth article! The simple answer here is that red light therapy works for hair growth, but it's also as almost always, part of a bigger picture.

If you're short on time, just read my summary below to understand the basics of this topic. If you want a deep dive, keep reading this entire article below!

Hair Basics

First up, let's talk about the basics of hair. We'll need that background to better understand the effects of light therapy later on in this article:

So, let's talk about hair growth science. There are loads and loads and loads of scientific reviews published on this topic, simply because it's such an important part of people's aesthetical appearance (1; 2; 3; 4; 5; 6; 7; 8; 9; 10). Reviews, here, analyze and integrate previous publications on the topic.

Human Hair Basics

So here's what you need to know. Human hair typically grows at a third of a millimeter daily (1). Humans also lose 100 hairs per day under normal circumstances (1). Here, you can see a hair follicle integrated into the human skin:

As you can see, there's a sebaceous gland near the hair, which also expels oil (12). But it's mostly the hair follicle that holds the hair, which is problematic in many cases - such as with hair loss. Hair loss strongly affects many people psychologically (1).

(Not me, as I'm thrilled shaving my hair and no longer have to deal with it since a decade!)

You don't have hair for aesthetical purposes only, however. Hair has a protective function, gives your body tactile input, and helps maintain your body temperature (3; 13).

The area around your hair is very metabolically active. That metabolism is necessary to maintain hair health. Anything that impairs overall metabolism thus impairs hair growth and can potentially induce hair loss. About that topic, researchers write:

"As the hair follicle develops, blood vessels originating from the deep dermal vascular plexus surround it. These vessels nourish the hair follicle and support nutrient delivery, waste elimination, and growth. Loss of blood supply to the hair follicles is associated with some forms of hair loss." (13).

So, with improper blood flow or nutrient delivery, you can imagine your hair health is impaired! Hair also have muscles and nerves - for an easy way to imagine the role of muscles here, think about your eyebrows that can move (13). Muscles also help your hair stand up straight when it's cold - such as on your lower arms and legs.

Next up:

Hair Growth Cycles

Hair growth has a natural cycle (2).

• The first "anagen" (growth) phase lasts 2 - 7 years (14). This is where the hair actively grows out of the hair follicle. Rapid cell division is the mechanism here, by which the hair grows. As a result, your hair grows longer and longer.
• Secondly, there's the "catagen" phase - which is a transitory period of 2 - 3 weeks long. Here the hair follicle shrinks and blood supply is impeded, meaning that hair growth stops.
• Thirdly, there's the "telogen" phase - at which nothing happens - lasting 2 - 4 months (14). After this phase is over, you lose the hair, and the growth phase starts again!

Most of the hair you have at normal times, is in the "anagen phase" - assuming your hair is healthy! Of course, under certain conditions, this is not the case, for instance, people with hair loss will have inhibited the ability of the body to be in the anagen phase, for at least part of their normally present hair pattern!

So the goal here, by maintaining metabolism and blood flow, is to keep your hair in the anagen phase without it shifting too quickly to the catagen and telogen phases. If you've got poor hair growth, your hair may not spend sufficient time in the anagen phase.

Potential Hair Loss Causes–Or Poor Hair Growth!

Stress can cause hair loss, but genetics can also play a role, and cancer treatment such as radio or chemotherapy can play a role (14). And, an absence of light can disrupt these hair growth phases, which is what has been happening in modern society. People are living indoors and no longer exposing their scalp to the sun, thereby very likely inhibiting hair growth!

I'll come back to this topic later. But, generally, any stressor can inhibit hair growth. And health promotion in general will promote hair growth.

Aging And Hair Loss

With age, problems arise. Here's what a recent review writes about that process:

" Studies estimate that 70% of men and 40% of women are affected by androgenetic alopecia. Men will classically present with receding temporal hairlines, described as hair thinning and loss in an “M” shape. Women will typically present with a widening part and thinning at the top of the scalp. A genetic predisposition to increased hair follicle sensitivity to circulating androgens causes this type of hair loss." (13).

So it's possible that if you do nothing, you'll end up with hair loss in older age, especially as a man! Personally, I already had a beginning "M" shape when I was 17, working in construction, and my supervisor commented that I'd get hair loss at an early age.

It is what it is!

One thing I do question is whether the "genetic predisposition to increased hair follicle sensitivity to circulating androgens causes this type of hair loss.". Many experts in the field, such as those in the Ray Peat community, question this belief. These people don't believe that androgens - primarily "male" hormones such as DHT - are responsible for hair loss!

This is a complex discussion. What's more likely is that low energy production, poorer thyroid health, worse circulation, chronic inflammation and other factors cause the hair loss and lower hair growth, in my opinion. My case there is complex though and I may publish an article on that in another day.

Nevertheless, keep in mind that red light therapy affects all these factors I've mentioned above - energy, inflammation, circulation, thyroid health, etc! We don't have any direct studies investigating those mechanisms, however, but it would be great to have more data on this topic!

The Importance Of Identifying The Correct Hair Loss Cause

The simple fact here is that it's generally harder to retain a full head of hair as you age, for both sexes! Identifying the correct causes is important there. You may have hair loss because of an infection, for instance. Fixing that infection may then reverse the hair loss.

Or, you may have a light exposure deficiency, such as very little red and near-infared exposure to your scalp - which often happens when people are spending all of their times under artificial blue light. Modern LED and fluorescent lighting emit tons of blue light and very little red, creating a light exposure environment that is dramatically different from what your ancestors would be exposed to.

Loads of evidence also shows that psychological stress can induce hair loss (15; 16; 17; 18). I've not experienced quick hair loss in my life, but I did experience quick graying during a difficult period! Many different mechanisms, such as stress hormones (cortisol), immune overactivity, and oxidative stress, can induce that hair loss (15; 16; 17; 18).

Other causes of hair loss are nutritional deficiencies and prescription medication. I'll return to the first later on in this article. The latter situation is complex, however, and a study states the following about that process:

"However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication." (19)

So, disease can cause hair loss, your body is under lots of pressure. That pressure makes your body allocate scarce resources towards your immune system, for instance, while giving lower priority to hair health. That dynamic is straightforward to explain from an evolutionary perspective - survival matters first and foremost during disease–not maintaining beauty!

So, in case of hair loss, it's essential to identify the correct cause of the issues.

What About Promoting Hair Growth?

I'll come back to this topic later on in this article. For now, know that countering chronic psychological stress, ensuring adequate high-quality nutrition, massages (that promote scalp blood flow), not smoking and drinking, and some prescription medication can all promote hair growth.

So hair growth and hair loss, in some sense, are two sides of the same coin. Generally (although there are exceptions), the more you promote hair growth, the less hair loss happens, and vice versa. This is a general principle in the animal kingdom - just think about an old lion who has lost his territory and now looks like a shadow of its former self, with hair falling out everywhere (4)!

Fortunately, there's good hope! As more and more science is emerging on reversing graying hair, the same is valid for promoting hair growth (5). So, let's consider the science on this topic, as red light therapy may be a game-changer here.

Here's what a review states about the developments on hair growth advancements:

"These [developments] include finasteride, minoxidil, topical prostaglandins, natural supplements, microneedling, low-level laser light, platelet-rich plasma, fractional lasers, cellular therapy, Wnt activators and SFRP1 antagonism." (7).

Not all of these are great, however. But let's explore one great option mentioned there, "low-level laser light", or "red light therapy" as it's now commonly known:

How Effective Is Red Light Therapy For Hair Growth?

So here are a few questions I want to answer, given the science on this topic:

• "Is red light therapy good for hair growth?"
• "How often to use red light therapy for hair growth?"
• "How much red light therapy for hair growth is necessary?"

The good thing is tbat Vladimir Heiskanen has a datasheet that contains 8,500 red light therapy studies on many different topics (20). He's also got a section on hair growth specifically - so let's look at these studies for their outcomes:

Hair Growth Studies - In Vitro And Animal Studies

Here, I'll explore in vitro (Petri dish) and animal studies on red light therapy for hair growth. In the Excel Sheet, Heiskanen has only included these foundational laboratory and animal studies here under the "hair growth" category (20). Nevertheless, these studies are useful, so let's go over them one by one.

First, the animal studies:

• A mice study compares 670, 680, 780, and 880 nm over 14 days and showed that a combination of two wavelengths worked better than a single one (21).
• Another mouse study compares 465 blue light, 513 nm green light, and 629 red light (22). Both green and red light stimulated hair growth at a 0.2 J/cm2 dose.
• A rat study tested 650 nm red light at 4.25 J/cm2 (23). The study shows that penetration depth matters for the best outcome.
• One more mice study uses 655 nm at 3 J/cm2 (24). Here, if there is skin damage, the light lowers the consequences for the hair follicles.
• Moreover, a 635 nm mouse study shows that light therapy activates stem cells and reactivates inactive hair follicles that have become small (25). Hair regeneration is the result.
• Another mice study uses 650 nm (26). Hair growth was increased by about 80% (27).
• A combination of 635 and 665 nm shows a negative outcome for the first time, whereby follicle length is lower in the group receiving the light therapy (28). Ten sessions of light therapy were used.
• One more 638 nm study has a positive outcome in mice (29). Here's a quote:

"Our data here suggest that red LED stimulates hair growth in mice and induces several potential mediators to stimulate hair growth from human dermal papilla cells. Therefore, red LED is a hopeful therapeutic modality for hair loss diseases. In addition, although LED light and low level laser share some characteristics, LED light source is more cost efficient and portable, can irradiate more surface area and produces less heat than LLLT. Therefore, LED therapy can be a convenient and safe strategy for hair growth from aspect of clinical practice." (30).

Then, there are the in vitro studies (31; 32; 33; 34; 35; 36; 37; 38; 39). These in vitro studies have positive outcomes and use blue, red, and near-infrared light. These studies have somewhat limited clinical applicability, though, but you can read them if you think they are fascinating! Total doses of 0.5 - 6 J/cm2 are used here.

Lastly, there's also one editorial published on blue light, but much more research is needed here (40; 41). Blue light affects the peripheral circadian rhythm, according to the article - the 24-hour day and night cycle in your body.

I'll supplement this opinion, however, with my article on red light therapy for hair loss - because the "hair growth" science that's specifically published is really minimal:

My Earlier Hair Loss Article

So, about a year ago, I went through all of the science on red light therapy for hair loss. I've included this topic in this article because, as I've stated before, there's a really good argument to be made that the processes of hair loss and hair growth are linked to each other and that the factors causing hair loss are counteracted by promoting hair growth.

Simple as that...

Here, I mainly investigated the "androgenetic alopecia" and "alopecia areata" conditions that cause people to lose their hair. Androgenetic alopecia is the most common form of hair loss for both men and women, contrary to what the name implies! Alopecia areata is an autoimmune disorder that leads to patches of hair loss on the skin.

Red light therapy can fortunately help in both conditions, although the evidence is by far the best in the former. There was not much research on alopecia areata when I wrote this article. Today, nothing has changed there in terms of evidence.

Now, you know the drill, probably if you're reading this...

Traditional medicine often uses prescription medication to counteract hair loss. Minoxidil is used directly on the skin where the hair loss occurs, and finasteride is taken orally (with, in my opinion, substantial side effects!)

So you and I need a better solution for different hair loss types!

That's where red light therapy comes in...

Most of the studies on red light therapy for both androgenetic alopecia and alopecia areata are positive! Studies show that 630 - 660 nm red light therapy promotes hair regrowth and improves hair density. There's better evidence here for the 660 and 670 nm range than for 630 nm. Loads of studies have come out on this topic in the last decade, fortunately!

For the best results, red light therapy should be applied three to four times weekly. Lasers and LEDs both show promising results, but as a consumer, it's best to opt for LEDs as a consumer as they are generally far cheaper. Also, according to the latest science, you don't need a super high power output for great results in this domain!

The most common-sense device to treat hair loss or hair growth is a red light therapy helmet. However, these devices aren't the most versatile and for most people, I recommend getting a red light therapy panel and using that light to be projected at your head (scalp). A helmet is often costly and only treats your head, and with a red light therapy panel, you can treat your head and your full body.

Hence, panels are a better investment - I'll give you some options in a later section!

With a panel, you'll just need a few minutes of treatment per day per area that's affected by the light. Then, you should be getting results...

We're not in heaven yet, though. Concerning hair loss, we need more studies on human beings. Long-term studies with treatment are also necessary and currently lacking. Often, you can get better results with longer-term treatment, but these results won't show because such long-term studies are costly to fund.

Also, before treatment with red light therapy, I recommend you still consult your physician. You'll want to rule out chronic psychological stress, infections, nutritional deficiencies, prescription medicine interactions, and so forth as factors that can inhibit your hair growth!

Nevertheless with red light therapy, you'll have a great non-invasive approach to promote hair growth and counteract hair loss conditions. Hopefully, as research progresses, red light therapy becomes a far more widely accepted treatment option for hair growth!

One thing I will do, however, is now go through some very recent reviews that have been published in 2024 and 2025 on this topic - to see whether I need to update my viewpoint from my red light therapy for hair loss article:

Latest Red Light Therapy And Hair Loss Reviews

So, let's consider the recently published red light therapy for hair growth reviews.

First, we've got a very recently published 2025 review study (42). The review included 34 previous studies on the topic of androgenetic alopecia. The somewhat controversial conclusion of the study is:

"The combination of minoxidil and [red light therapy] does not significantly improve outcomes compared to minoxidil alone for treating androgenic alopecia." (42).

There were no differences between the 8 and 12 weeks post-treatment. Even though the study pooled all the statistical outcomes of these studies (called a "meta-analysis"). According to this review, there was no difference in hair growth or diameter.

Remember that minoxidil alone was compared with minoxidil and red light therapy. So, if you're using the former, it may be less useful to integrate red light therapy into your routine.

Then there's a 2024 review (43; 44). This general review looks at various therapies for countering hair loss, including microneedling and Pulsed Electro-Magnetic Frequencies (PEMF). I'll focus on light therapy here, however. There's loads of discussion of using different lasers for hair loss as well, and combination therapies such as microneedles that are put into the skin and that contain a laser.

Here you can see an example of a specialized laser for hair loss:

And, here you can see the different options for light therapy, as well as their combinations:

Lastly, you may want to know about the different mechanisms this review has found, in which aspects of hair loss can be influenced by light therapy. Figure 5 of that review displays these biological mechanisms in great detail - so this shows that light therapy affects overall hair health and growth at many different levels:

It's great to see how much more detailed these reviews have become in the last few years since I wrote my original red light therapy for hair loss article! Here's what the researchers write in their conclusion:

"In particular, low-level laser therapy demonstrates significant potential due to the photobiomodulation effects on mitochondria, which can enhance cellular energy production and potentially stimulate hair growth. The other light sources, including fractional and nonablative lasers, as well as blue and yellow light therapies, offer a range of options that are becoming increasingly popular treatment options for AGA, particularly as adjunct treatments for individuals who are non-responsive to FDA-approved solutions." (44)

Overall, there's excellent efficacy with minimal to no side effects. The issue is, however, to find the best protocol. With the many different wavelengths used and many different methods of applying the light therapy - such as ablative lasers, microneedling lasers, or a plain LED helmet - you can't yet say what protocol is best because all of them haven't been compared to each other yet.

I wish I had an easy answer!

Another 2024 review had a similar approach and doesn't just look at light therapy but any therapy to counter androgenetic alopecia (45). Here's the outcome, which is quite good in my opinion, as it accords to my general strategic approach in holistic health:

"We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management." (45).

So, the goal is not to restrict yourself to just one strategy but to use multiple ones that have proven efficacy to achieve a goal. You could try light therapy, for instance, and platelet-rich plasma (PRP), which is low risk, and enhancing your nutrition and supplementation program, and opt for an inexpensive hair transplant in Turkey, for instance. All of these I would personally use before I'd ever take finasteride for hair loss, which suppresses the male DHT hormone and, therefore, has horrible side effects, in my opinion.

Recent reviews show that these drugs, such as dutasteride, are very effective (46). But dutasteride blocks even more types of 5-alpha-reductase enzymes and, therefore, should have an even worse profile than finasteride - which has many horror stories on the internet! In my opinion–this is not medical advice–if you value your health, you're better off saving a few thousand USD for medical tourism and getting a hair transplant!

But these are the most recent reviews on red light therapy for hair loss, published in 2023 - 2025!

Red Light Therapy Protocol For Hair Growth

Overall, I'd still mainly use 630 and 660 nm red light wavelengths. And I'd use a total dose of up to 10 J/cm2 per day. The in vitro studies use even less than that dose, up to 6 J/cm2, although their value is lower than the animal and especially the human studies.

There's still less evidence of using near-infrared light for hair growth or loss. Treatment should occur three or four times weekly. For the best results, you don't just use red light therapy but many other strategies for promoting overall health and hair growth.

Next up, let's explore the results we've been getting with these protocols:

Red Light Therapy For Hair Growth Before And After

So here I want to talk about my good friend Alex Fergus, who is also the founder and owner of this website. Alex has had hair loss just like me and wanted to promote his hair growth, ideally restoring it. It's a bit of an example of what not to do, which is the same for me, as we both waited very long until our 30s until starting treatment here.

The general perception of many people using red light therapy for hair growth and loss is that it works much better if you start from an early age. So, if you've got the first sings of thinning hair, or some patches that start to have less density, you'll ideally start treatment immediately!

If you wait for many years until starting treatment, or even a decade, you'll have to temper your expectations big time!

So here's Alex Fergus' 6-month experiment with topical minoxidil used on the head, combined with a laser red light therapy helmet:

There are other options, though, as here's Alex using an LED helmet for months as you can see:

But if you've watched the videos, you can see that the treatment didn't result in better hair growth for Alex. That's unfortunate but reality. Do you wish access to much more red light therapy for growth before and after success and failure stories? Then join our Facebook group below - as I've found a dozen+ threads you can interact with:

Fortunately, unlike the videos listed above, many people in our Facebook group have found great benefits to hair growth and loss!

Best Red Light Therapy Devices For Hair Growth

The answer here isn't really simple. Technically, you'd think that the red light therapy helmets would be the best option here. These are the following that my friend Alex Fergus has reviewed:

• For the Currentbody Skin LED Hair Regrowth Device use code CBALEX for 15% off with the following link.
• For a Mito Red Light Helmet review product, either the laser or LED, use THIS link and code ALEX5

However, the best option depends on how long your hair is. You're likely better off with a panel if you've got shorter hair. The reason to get a helmet is because you can project the light far closer to the hair follicles.

But with shorter hair, red light therapy panels are a far better option because they're far more versatile for health. You can opt for a budget tabletop panel, for instance, that not only allows you to treat your hair but many body parts such as joints, your facial skin, etc! Or you could opt for a bigger wall panel - and as long as the light hits your scalp, you should be getting the benefits!

Many Other Treatments to Consider for Hair Growth

So, let's talk about hair growth and hair loss in context. Both are highly dependent on your general health - just like libido and fertility are! You may have noticed that people lose their libido the first thing once their health deteriorates. That happens because the organism focuses on survival first.

This is a topic I've written about before in my article on red light therapy for hair loss. Your digestion, your overall inflammatory levels, stress levels, and hormones all have a massive impact on hair growth and overall hair health.

For inflammation, you can find tons of evidence showing that inflammation is tied to androgenetic alopecia (47; 48; 49; 50). The same is valid for digestion although I cannot find tons of studies on the topic - likely because most researchers don't take a holistic health viewpoint (51; 52). And, surprise, surprise, stress, hair loss as well as poor hair growth are extremely solidly linked (53; 54; 55; 56; 57; 58).

This brings me to the many different health strategies I recommend anyone follow, regardless of context:

• Getting bright light exposure during the day, hopefully with some morning sunlight.
• Avoiding bright light exposure at night, especially blue light exposure to the eyes.
• Proper nasal breathing 24/7 - you only need to breathe through your mouth during extremely intense cardio sessions, approximating your max heart rate and VO2 max. Get a high-quality air purifier if you don't have access to healthy air (most cities)
• A healthy diet - follow a diet that works for you. Your diet not only affects your overall health but also your hair growth. Examples here are biotin (found in various foods but especially egg yolks and liver), zinc, iron, vitamin D, omega-3 fatty acids from fatty fish, shellfish, and similar. And, of course, simple protein!
• Prioritizing sleep and getting 7 - 9 hours of sleep at night - this is true for 80% of people, genetic freaks may sleep a little bit shorter.
• Movement throughout the day. Exercising a few times per week, whereby a combination of long-duration cardio and strength training or high-impact interval training is probably best.
• Minimizing psychological stress. Also try to avoid physical stressors such as noise and EMFs.
• Get a reverse osmosis filter for your water.
• Avoid toxin exposure in general, whether it's from cosmetics, or smoking, or drinking excess alcohol.

All of these factors should also promote your digestion and hormonal health, promoting hair growth in turn!

Next to that, you could use different strategies to promote hair growth, next to light therapy. Examples here are massage or microneeding for scalp health.

Stress management also directly promotes hair growth. Hair growth is impeded if you're running hard on cortisol and adrenaline. In my case, for instance, I can notice a real difference in hair growth if I simply don't ingest any caffeine - but my body breaks that substance down very slowly in my case (because of a genetic mutation).

Lastly, sure, you can combine light therapy, general health support, and supplements, if necessary, with compounds such as topical minoxidil. Personally, I'd always avoid finasteride and dutasteride, especially as a man, as the DHT hormone that's inhibited is just as important as testosterone, in my humble (but informed) opinion!

That's a topic for another day, however. But you can find plenty of free content on the effects of inhibiting DHT online nowadays! The information is everywhere!

Conclusion: Understand The Big Picture For Hair Growth!

Yes, yes, people may get sick reading my articles and me constantly zooming out, saying that the whole picture is far more complicated than a simple biochemical process that determines a topic. Whether you talk about joint health, or brain health, or hair growth, general health matters a lot. So your simple day-to-day habits greatly impact your hair growth in general.

Nevertheless, I hope I've given you more insight into questions such as "Should I use a red light therapy helmet for hair growth" or "What's the best red light therapy for hair growth at home?"

One of the hair growth helmets is best if you've got longer hair, in my opinion, and a panel should be great if you've got shorter hair. Theoretically, you can also use a red light therapy panel directly on the skin, against the scalp, if you've got long hair, but that isn't easy to use that way for most people.

Overall, however, the 630 and 660 nm wavelengths seem to still have the best level of evidence for hair growth. And I'd recommend using dosing parameters of up to 10 J/cm2 per day, with treatments three or four times weekly!

It's that simple! Good luck!

Items Mentioned:

✅ For the Currentbody Skin LED Hair Regrowth Device use code CBALEX for 15% off with the following link: https://aferg.co/currentbody
✅ For a Mito Red Light Helmet review product, either the laser or LED, use this link and code ALEX5: https://aferg.co/7d221

Writer Bio

This is a post by Bart Wolbers of Lighttherapyinsiders. Bart finished degrees in Physical Therapy (B), Philosophy (BA and MA), Philosophy of Science and Technology (MS - with distinction), and Clinical Health Science (MS), has had training in functional medicine and is currently chief science writer.

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