Research Team

Does Marijuana Cause Hair Loss? A Review of the Evidence

Weed, Mary Jane, pot, grass, reefer – all of these refer to the most commonly used illicit drug in the United States and around the world: marijuana (1).

In this post, I’ll offer a brief introduction to marijuana. I’ll then discuss a potential side effect of the drug that is not often talked about – hair loss.

You’ll learn the ways in which marijuana may contribute to thinning and hair fall, as well as signs to look out for. At the end, I’ll then share some tips on combating marijuana-induced hair loss.

Let’s get started!

Marijuana: An Introduction

Marijuana, more commonly referred to as weed, is a psychoactive drug from the Cannabis plant. This drug has been used for centuries, both recreationally and for medical purposes.

The most common effects of marijuana usage are a change in perception and heightened mood. But there are other effects – both short-term and long-term – including dry mouth, imparied short-term memory, and altered brain development (2).

A Curative Substance or a Health Threat?

While marijuana is gaining legal ground across the globe, there is still much debate as to its true long-term effects (3). And there are also questions about its actual efficacy as a medicinal treatment (4).

Marijuana – or more specifically the cannabinoid Tetrahydroannabinol (THC) – has been studied extensively for decades. It has been indicated as an effective treatment for everything from chronic pain to epilepsy and even Post-Traumatic Stress Disorder (PTSD) (5, 6, 7).

The anecdotal evidence of success is overwhelming, and there are many proponents for its use.

However, the drug has gained a dubious reputation in more recent years with research showing the effects of long-term use.

So, is marijuana a curative substance or a health threat?

The truth is likely somewhere in the middle.

There is no doubt that marijuana can have significant effects on mood and perception, and it can be a helpful treatment for many conditions under the watchful eye of a physician.

But too much of anything – even a ‘good’ thing – is bad. This is why moderation is key.

Can Marijuana Cause Hair Loss?

There is a lot of research – both peer-reviewed and not – that outlines the health benefits and risks of regular marijuana use.

While hair loss is not often the focus of these studies, there is evidence to suggest that marijuana may contribute to thinning and hair loss.

Marijuana is Linked to Hormonal Changes

There are an array of hormones that play a role in the male reproductive system.

Testosterone is the one that’s most often thought of, but other hormones including LH and FSH also contribute to sexual reproduction (8).

In fact, LH and FSH are gonadotropins which contribute to the production of testosterone. This means that an imbalance – either too much or too little – of these hormones can have some noticeable effects on the individual.

As you very likely know, testosterone is the hormone that’s responsible for a man’s, well, manliness.

This hormone is responsible for regulating fertility, muscle mass, fat distribution and storage, and red blood cell production (9). As you might imagine, then, an imbalance can cause many side effects.

But did you know that testosterone also plays a role in the progression of Androgenetic Alopecia (AGA) (10)? AGA, also known as Male-Pattern Baldness (MPB), is the most common cause of hairline recession and balding in men.

There are many factors hypothesized to contribute to AGA, but a sensitivity to the androgen hormone Dihydrotestosterone (DHT) is the most widely believed. And coincidentally, testosterone is a precursor to DHT.

One study on the endocrine effects of marijuana use in men showed that the drug can lower LH and FSH levels (11).

This sounds great in theory, as lower testosterone levels mean decreased production of DHT. However, an underproduction of testosterone can itself lead to numerous side effects (12).

The most common of these effects are sexual in nature. These include reduced sex drive, inability to get and keep an erection, and even infertility.

And while the link between marijuana use and hair loss may not be direct, I would be concerned about using a substance that has been proven to alter hormone levels.

It Can Slow Cellular Activity

From the outside, the growth of hair seems to be a simple process. But there are actually a lot of factors which contribute to hair growth (or lack thereof).

One factor is the rate at which cells divide.

Cellular division occurs in the part of the hair follicle known as the matrix. When cells divide as they should, this results in hair growth. But when division is slowed down – or even halted entirely – then problems will arise.

The most common problem is that of thinning, or poorly growing hair. And if not treated, it can result in total loss of that particular hair strand and any other strands affected.

So, what does marijuana have to do with cellular activity? According to a 2007 research study, quite a lot actually (13)!

Cellular activity can be impacted by many things and, according to the results of the aforementioned study, endo- and exocannabinoids are two of them.

Cannabinoids are a class of chemical compounds that utilize cannabinoid receptors in cells to alter neurotransmitter release in the brain (14). Endocannabinoids are those which are naturally produced by the body, while exocannabinoids are found in plants such as marijuana.

There are cannabinoid receptors all throughout the body, including at the hair follicle. And cannabinoids such as marijuana have been shown to inhibit cellular division in the follicle.

In some cases, the presence of cannabinoids even caused the hair to prematurely enter catagen phase!

Marijuana May Induce Stress

There is a certain belief that seems to connect weed with relaxation. But according to extensive research on the topic, the opposite is true.

During periods of mental or physical stress, the body produces an excess of the hormone cortisol (15).

THC, the main component of marijuana, has been shown to increase cortisol levels and, therefore, induce a stress response (16).

So, what’s the link to hair?

Well stress can induce a form of hair loss known as Telogen Effluvium (TE).

There are three stages in the hair growth process: anagen (active growth), catagen (transition), and telogen (resting).

The majority of your scalp should be in the anagen phase at any given time. But stress – either physical or mental – can cause the follicle to enter telogen phase prematurely.

When this happens, the hair stops growing and, eventually, it sheds.

The condition then leads to an increased amount of shedding, which contributes to thinning and even hairline recession.

The good news is that TE is often a temporary condition.

Once you stop smoking and the body has been given time to detox from the presence of THC, then the condition will often improve.

The Signs of Marijuana-Induced Hair Loss

Alopecia triggered by marijuana is essentially the same as many other types of hair loss. This means that you’ll see signs similar to those in men with Male-Pattern Baldness (MPB).

Here are just a few signs to look out for.

Hairline Recession

MPB, also referred to as pattern hair loss, is a genetic condition. If left untreated, it triggers a progressive form of balding that starts at the temples.

The beginning stages of this loss will take on the shape of the letter “M”. But as the skin at the temples are thinner, it makes sense that hair loss caused by other things – including marijuana – would affect the follicles there, too.

You’ll likely notice that the hair at your temples is seemingly thinner. This will slowly morph into hairlines that recede behind the natural hairline on the forehead.

Thin, Wispy Hairs

When the follicles are unhealthy, it’s difficult for them to produce strong, healthy hair strands. Because of this, you’re likely to notice that your hairs are thinner and weaker as the hair loss continues.

The cause of this is likely related to inflammation, which can occur due to irritation or even increased cortisol levels.

As the follicle becomes inflamed, the hair strands are strangled. They are, therefore, thinner when produced.

The most common place to notice these hairs is at the temples. However, you may also see it at the forehead, or even the crown.

Increased Shedding

Before you begin to notice thinning on the scalp, you’re likely to notice an increase in shed hairs.

We naturally shed anywhere from 50 to 150 hairs per day. But if you see more hair in the drain after your shower, or on the pillow in the morning, then you may be experiencing an increase in shedding.

This is a natural part of the hair growth process, as hairs must be shed during telogen phase for new growth to occur. When your follicles are prematurely pushed into telogen, though, this is when you’ll notice significant loss in a short amount of time.

How to Combat Hair Loss Caused by Marijuana

Whether you’ve been partaking for years or you’ve just recently begun, you may be wondering how to combat (or even prevent) marijuana-induced hair fall. Here are a few tips for your consideration.

Decrease Usage

The most obvious solution to stopping marijuana-induced hair loss is to halt use altogether. But if you’re using marijuana as a medicinal supplement under the guidance of your doctor, your next best bet is to decrease usage.

Increase Nutritional Supplementation

If decreasing usage isn’t a possibility, or if you feel you’re otherwise lacking, then I strongly recommend you increase your nutritional supplementation.

There is much debate surrounding the effects of diet on hair. However, it’s obvious that a poor diet contributes to a poorly functioning body.

If you’re not getting enough of critical vitamins and nutrients – including vitamins A, B, C, and D, niacin, and iron – you could be putting your hairline at further risk.

And even if you change up your diet by increasing your intake of lean meats, fruits, and vegetables, you may still need a hand. That’s where dietary supplements come in.

If you suspect nutrient and vitamin deficiencies, the first place to start is with a doctor’s appointment. Your physician can run a panel to see exactly which vitamins you’re lacking, and then make recommendations to improve your levels.

Stimulate the Scalp

Stress, inflammation, and hormone imbalance can wreak havoc on the scalp. These issues – individually, and combined – can then lead to tension and even scalp calcification.

The good news? The effects of these problems can often be reversed if treated early enough. How? With scalp stimulation.

Scalp stimulation is manipulation of the scalp using your fingers (such as with massage) or a specialized device (such as with dermarolling). These techniques can break up the calcification, reduce tension, and increase blood flow to the follicles.

And if that sounds too good to be true, you’ll be happy to know there’s scientific proof to back these claims.

Mechanical stress is a process that’s believed to contribute to the progression of AGA (17).

Scalp stimulation exercises, such as massage, have been shown to reduce tension of the scalp so as to ensure a healthy environment for hair growth.

This technique works by applying varying levels of pressure to the skin so as to increase elasticity and break up any physical causes of scalp tightening (such as calcification) (18).

With a more relaxed scalp, there is also less of a barrier to the delivery of blood to the follicles.

While massage alone is a great technique to add to your routine, there are other techniques to consider. A more advanced one is microneedling.

Microneedling, also known as Collagen Induction Therapy (CIT), is a technique that utilizes tiny needles to penetrate the skin. When these micro wounds heal, they induce the three-step healing process (19):

  1. Inflammation
  2. Proliferation
  3. Maturation

This procedure has been shown to reduce scarring and decrease hyperpigmentation. But it’s also been shown to increase hair count after 12 weeks of consistent practice (20).

Even better, microneedling has been shown effective in those who didn’t respond to more traditional (e.g. Rogaine and Propecia) treatments (21).

While the studies linked above seem to focus mostly on pattern hair loss, there’s also reason to believe they could help thinning induced by marijuana. This is because many of the mechanisms of loss – such as inflammation and premature induction of telogen – are shared between the two.

Treat the Underlying Cause

There are many reasons to believe that marijuana can contribute to hair fall. That doesn’t mean, though, that there isn’t another underlying issue.

Pattern hair loss affects between 30 and 50 percent of men by the age of 50 (22). This number is lower for women, but it’s still a significant problem for them, too (23).

What I mean by this is there’s a very good chance that marijuana alone is not the cause of your sudden hairline recession and thinning. And if you are like 30 to 50 percent of the population, then pattern hair loss may be the problem.

Androgenetic alopecia is treatable, but there is currently no cure. However, many of the techniques mentioned above – including nutrient supplementation and scalp stimulation – can be a great way to combat thinning and balding.

There are also drugs on the market – namely Rogaine and Propecia – which target this form of hair loss specifically.

To treat hair loss effectively, you must treat the underlying cause. This is why I highly recommend that you consider all possibilities while investigating the cause of your current hair condition.

Conclusion

Marijuana is the most popular recreational drug in the United States, and it’s quickly becoming legalized in the US and around the globe. But legalization doesn’t mean that the drug doesn’t come with side effects.

The most common side effects are cognitive and mental, but one that many people do not discuss is hair loss.

There is scientific proof to show that regular use of marijuana can contribute to hormone imbalance, reduced cellular activity, and even stress. All of these can contribute to hair loss in their own way.

If you suspect you’re suffering from hair loss caused by weed use, your first step is to stop or reduce usage. You’ll then find the other steps recommended, including diet supplementation and scalp stimulation, to be helpful contributors to regrowth.

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