Marijuana is a drug used both recreationally and medicinally.
Although this drug may be of benefit to some populations suffering from specific diseases, the adverse effects of recreational marijuana may outweigh the benefits.
One of these adverse effects could very well be hair loss.
So, how does marijuana cause hair loss? In this article, I’ll explore the preliminary research that suggests marijuana may lead to excess hair shedding.
What Is Marijuana?
Marijuana is a plant that contains cannabinoids. These are active phytochemicals that exert different effects on the body by interacting with molecular signaling systems.
Marijuana, in contrast to other Cannabis plants like industrial hemp, contains high levels of tetrahydrocannabinol (THC). Unlike the other cannabinoids in marijuana, THC is psychoactive cannabinoid. This means that it impacts the way the brain functions.
THC also influences the body’s systems in other ways.
Key Takeaway: Marijuana contains phytocannabinoids and is specifically high in THC, a psychoactive cannabinoid.
The Endocannabinoid System
The endocannabinoid system is a group of receptors. It includes CB1 and CB2 receptors along with the families of TRPV and PPAR receptors.
All of these receptors are distributed throughout various tissues in the body.
When cannabinoids like THC enter the body, they bind to these receptors. As a result, they can change the ways cells function and communicate with each other.
THC and all the other cannabinoids found in the cannabis plant exert their effects on the body through this system of receptors.
- The endocannabinoid system contains CB1, CB2, and the families of TRPV and PPAR receptors.
- These receptors are distributed throughout the body, allowing cannabinoid like THC to influence the way the body functions.
Does Marijuana Cause Hair Loss?
Now that you know how marijuana influences the body’s systems, you can better understand how marijuana might cause hair loss.
Below, I’ll discuss the possible mechanisms behind marijuana-induced hair loss.
Combustion, Contamination, and Free Radical Damage
Whenever something is burned, it always creates combustion byproducts. The purity of the product will determine how toxic these compounds are. But, combustion byproducts always have some degree of toxicity.
This means that even the purest of marijuana can produce toxic compounds.
Marijuana is often smoked using marijuana cigarettes, bongs, or pipes. This is one of the preferred routes of administration because of its fast-acting effects. Absorption through the lungs enters the bloodstream very quickly.
The downside of this is that Polycyclic Aromatic Hydrocarbons (PAHs) are produced as a result.
PAHs are fat-soluble compounds that easily pass through cell membranes (1). They are first metabolized by enzymes in the body that produce pro-carcinogenic metabolites.
These metabolites increase the free radical concentration within cells.
Free Radicals, Inflammation, and Hair Loss
So, what does this have to do with hair loss?
Hair follicle cells, especially the dermal papilla cells (DPCs; the cells responsible for signaling hair growth) are extremely sensitive to free radical damage (2). Once free radicals damage these cells, it impairs hair growth.
Free radical damage can also stimulate inflammation through the activation of NF-κB, a pro-inflammatory transcription factor (5). When free radicals activate NF-κB, this transcription factor moves to the nucleus where it influences the production of genetic material.
It shifts gene expression to pro-inflammatory by increasing the production of:
- Cyclooxygenase (COX) enzymes which produce all the pro-inflammatory prostaglandins of the body
- Lipooxygenase (LOX) enzymes which produce pro-inflammatory thromboxanes and leukotrienes
- Pro-inflammatory cytokines which are signaling molecules that tell cells to upregulate inflammatory mediator production
Prostaglandins, thromboxanes, and leukotrienes are inflammatory mediators. Depending on what kind of mediators are produced, they can either have generally pro-inflammatory or anti-inflammatory effects.
In the presence of high levels of omega-6 fatty acids in the body, excess COX & LOX activity stimulated by free radical-induced NF-κB activation can mean massive amounts of inflammation.
The production of pro-inflammatory mediators can directly antagonize hair growth and produce more free radicals, creating a vicious anti-hair growth cycle (6).
Altogether, free radical damage, which can be upregulated by PAHs from marijuana combustion, and the subsequent inflammation may cause hair loss.
Street Marijuana Contamination
Additionally, street marijuana samples have been found to be contaminated with toxins like ammonia (9). Ammonia is required by the body in very small concentrations.
However, excess ammonia can be extremely toxic. Once ammonia gets inside cells, it can deplete adenosine triphosphate (ATP), the energy currency for the whole body (10).
This ATP depletion is directly toxic to the nervous system and the brain. But, it may also prevent hair growth.
ATP is produced by the mitochondria, tiny little organelles within all of our cells. While the exact role of mitochondria and ATP may play in hair loss is unknown, we can make some assumptions based off of the findings of one interesting animal study.
In mice who were depleted of mitochondrial DNA, the genetic material needed to assemble mitochondria, they exhibited classic signs of aging: hair loss and skin wrinkling (11).
Because mitochondria produce ATP for the cell, this suggests ATP production may be critical for hair growth. This is not surprising considering ATP fuels all cell functions and collective tissue actions like hair growth.
Interestingly, when researchers restored mice mitochondrial function, their hair regrew and skin returned to normal.
Considering the potential for ammonia contamination, some marijuana may cause hair loss through ammonia toxicity.
Toxic Compounds Associated with Marijuana Use May Cause Hair Loss
With the overall toxicity that can potentially occur as a result of marijuana use, it’s safe to say that it’s best to stay away. If you’re looking to grow your hair, marijuana may be a no-go.
- Even the purest marijuana, when smoked, creates combustion byproducts called PAHs. These elicit free radical damage which is directly toxic to hair growth. They can also upregulate inflammatory activity (mediators and cytokines) through NF-κB which produces more free radicals and has a direct antagonistic effect on hair growth.
- Some marijuana samples may also be contaminated with toxins like ammonia. Ammonia depletes ATP which is not only toxic to the nervous system but may also hamper hair growth. Evidence from animal studies suggest ATP depletion may cause hair loss.
- If you’re looking to grow your hair, marijuana may be a no-go.
THC, the Endocannabinoid System, and Hair Loss
Besides the potential toxicity of marijuana, THC may directly affect hair growth.
Researchers attempted to investigate the effects of THC on hair (12). To do this, they created a full hair follicle organ culture that allowed them to test the effects of THC on the whole follicle as opposed to single cells.
What they found was this: when THC was added to the organ culture, it dose-dependently inhibited hair elongation or growth.
After adding a CB1 receptor antagonist, it reversed the hair growth inhibition by THC. This means that the hair growth suppressant effect of THC is caused by its activation of CB1 receptors.
This doesn’t necessarily mimic the effects of marijuana when administered to the whole body because it’s not a direct application to hair follicles like in the study.
However, cannabinoids like THC are known to accumulate in the sebaceous glands of the hair follicle with marijuana use (13). This suggests that smoking marijuana could cause THC to infiltrate the hair follicle and possibly cause hair loss.
So, even when marijuana is ingested orally to avoid combustion products, it still may pose a risk to hair health due to the effects of THC.
- THC was shown to inhibit hair growth via the CB1 receptor in one organ culture study.
- This does not necessarily mimic how THC could affect the hair follicle when administered to the whole body. However, THC is known to accumulate in the sebaceous gland following marijuana use.
- Even when marijuana is ingested orally to avoid combustion byproducts, it may still pose a risk to hair health.
Does CBD Cause Hair Loss?
THC isn’t the only cannabinoid in marijuana. Albeit in lower concentrations, cannabidiol (CBD) is still present. There are also various other cannabinoids present, but their effects on hair have not been explored as of yet.
CBD is much more concentrated in hemp extracts that are produced from the low-THC industrial hemp plant.
CBD, unlike THC from marijuana, is not likely to have a negative effect on hair. This is because it doesn’t activate the CB1 receptor that inhibits hair growth.
In fact, CBD may have a protective effect on hair. Preliminary studies suggest that CBD may normalize sebum production (sebostatic effects) as well as exert anti-inflammatory action on the skin (14).
This is believed to occur as a result of CBD’s activation of certain TRPV receptors and inhibition of NF-κB activation. This leads to the reduction of sebum production and inflammatory gene expression.
This may be beneficial for one type of hair loss: AGA.
Although hormones play a distinct role in AGA, the effects of excess male hormone activity can also exacerbate the condition (15).
One of the hallmarks of AGA and a consequence of male hormones is excess sebum production. This provides the perfect conditions for bacteria like P. acnes to proliferate inside hair follicles.
As P. acnes continues to grow, it continues to produce more and more porphyrins which are potent inflammatory molecules.
More sebum also means more potential for sebum oxidation. Oxidized sebum contributes to free radical damage (16).
These combined effects can not only damage the skin around hair follicles but also directly stimulate hair shedding, as mentioned before.
With the collective anti-inflammatory and sebostatic effects of CBD, it may help intervene in the vicious cycle that underpins AGA.
So, although THC may be toxic to hair growth, the non-psychoactive CBD counterpart is likely not.
- Marijuana also contains lower amounts of CBD.
- CBD, unlike THC, is a CB1 antagonist. CB1 activation is what mediates hair loss caused by THC.
- Moreover, CBD may have protective effect on hair. It has both sebostatic and anti-inflammatory properties that may mitigate some factors in AGA.
- Although THC may be toxic to hair growth, CBD is likely not.
Other Side Effects of Marijuana: It’s Not Just Hair Loss
Beyond its possible negative effects on hair health, marijuana also results in a host of other adverse effects, such as (17):
- Impaired short term memory
- Altered judgment
- Impaired motor skills
- Increased risk of psychosis
When use begins in teenage years, chronic marijuana users may experience:
- Altered brain development
- Poor educational outcome
- Cognitive impairment
- Diminished life satisfaction
Contrary to how marijuana is often portrayed, it is not a benign, non-addictive substance. Chronic use, especially in adolescent years, can result in severe consequences.
- Marijuana is not a benign substance and its adverse effects extend beyond its potential impact on hair growth.
- Adolescents are seemingly at higher risk for the long-term adverse effects.
Can Marijuana Truly Contribute to Hair Loss?
Marijuana contains high levels of THC. It is much higher in concentration compared to other cannabis plants like industrial hemp.
Marijuana may contribute to hair loss in a few ways. The combustion byproducts that result from smoking marijuana can cause free radical damage that is directly toxic to hair growth. Additionally, free radicals stimulate inflammation that further exacerbates hair shedding.
This drug also has the potential to be contaminated with toxins like ammonia. Depletion of ATP by ammonia may contribute to hair loss, according to some animal research.
Additionally, THC is believed to directly antagonize hair growth through the activation of the CB1 receptor. Contrastingly, THC’s non-psychoactive counterpart, CBD, is a CB1 antagonist. This cannabinoid may even confer protective effects to hair.
Despite these consequences, marijuana is a drug that can have dangerous long-term downsides. Examination of the literature tells us that adolescents may be at a higher risk.
Whether you are experiencing hair shedding or not, rethinking marijuana use (especially recreational) is a good idea.
Have you experienced marijuana-related hair shedding? When did you begin to notice it? What was your experience? Leave a comment with your story below.