Young people growing up in today’s society have more pressure on them than any previous generation. Societal standards of beauty, financial success, social media and more are contributing to higher rates of anxiety, depression, and stress, which is resulting in people starting to lose their hair at a younger age (1).
Whether it be poor diet, stress, hormonal changes, or another factor, the reality is that many young people are losing their hair.
Marijuana use throughout the country is also on the rise. As more and more states recognize marijuana for its medical benefits and continue to legalize it, the number of people who use it regularly is going to continue to steadily grow. There has been speculation that the rise in premature hair loss and marijuana use (young people tend to use marijuana at higher rates (2)) could be correlated.
Can marijuana cause hair loss? If so, how? Does it affect pattern hair loss? These questions and more are what we are going to be discussing throughout this article. We are going to take a research-based look at the evidence to help determine whether or not you need to worry about using marijuana if you are suffering from hair loss.
The two ways marijuana may lead to hair loss
One of the reasons for marijuana’s rising popularity and changing legal status is due to the many proven health benefits. But for an industry that is growing as fast as the marijuana industry, sometimes there may be negative side effects that don’t get enough attention as they should, one of which may be hair loss.
Let’s take a look at the two primary ways that people claim marijuana can cause hair loss.
First: physiological effects
The majority of people that consume marijuana do so by smoking it, and this is often where people get things mixed up.
Although studies have shown that smoking releases carcinogens that can lead to androgenic alopecia (AGA; male/female pattern hair loss), there are no studies linking smoking marijuana to hair loss (the smoking studies were conducted on tobacco users). Granted, if you mix tobacco with marijuana (which many folks do) then you are subjecting yourself to a higher risk of developing pattern hair loss (3). But, does this mean marijuana doesn’t affect hair loss directly? Not quite.
THC is the psychoactive ingredient in marijuana (i.e. what gets you “high”) and is what might be linked to hair loss. THC is a cannabinoid that attaches to cannabinoid receptors throughout the body, including those that are in your hair. A study conducted in 2007 found that when THC binds to cannabinoid receptors in hair follicles it can lead to inhibition of elongation of hair follicles are negatively effects the distribution of vital proteins throughout the hair (4). The researchers also found that THC can induce the catagen phase (transitionary phase before the resting phase) of the hair cycle, meaning that less hair will be in the anagen (growth) phase of the hair cycle which may lead to thinning.
The problem is that every article you read about marijuana and hair loss site the same study, and only that study. This is because it is, in fact, the only study of its kind, and while it is a good indication that further research is needed, conclusions cannot be made off a single study. Any article that is claiming that marijuana directly affects hair loss is basing that claim off a single study and should not be taken at face value.
But, what about how marijuana indirectly affects hair loss?
Second: how marijuana might indirectly affect hair loss
Everybody knows the stereotypical association between a marijuana smoker and someone who is lazy, snacks, plays video games all day, etc. This leads people to assume that marijuana leads to weight gain due to poor nutritional/health choices which leads to hair loss (which is a fair assumption because studies show that poor nutrition can cause hair loss (5,6)). These assumptions may have some legitimacy though.
Although research has shown that marijuana users are not necessarily more obese than non-users (7), other studies have shown that the nutritional value of the food that people consume when smoking marijuana is lower than in those who don’t (8,9). This could theoretically contribute to hair loss (although again the direct connection has not been studied).
Another way that marijuana may indirectly affect hair loss is by affecting cortisol levels.
Cortisol is the hormone that is produced by the body in response to stress. Elevated cortisol has been shown to cause a condition called telogen effluvium (10), which is when you hair rapidly transitions from the anagen (growth) phase to the telogen (resting) phase of the hair cycle which can cause thinning across the scalp.
Research has shown that marijuana, contrary to its stigma as a “mellow drug”, increases cortisol levels (11), meaning it may increase stress and subsequent stress-induced hair loss it its users.
Let’s finally answer the question: will marijuana cause hair loss?
Just like most things hair loss related, we do not have enough evidence to make any conclusions, which also means that any article that does is not being genuine or telling the entire story.
In terms of direct effects on hair loss, there is one study that showed that THC may affect the hair growth cycle, meaning it may affect androgenic alopecia directly. While this is intriguing, researchers still need to confirm the findings, at bare minimum, with secondary and tertiary studies before any conclusions are made.
As far as indirect effects on hair loss marijuana has been proven to affect quality of nutritional intake and elevate cortisol levels, both of which could lead to hair loss. Fortunately both stress-related and nutritional deficiency-induced hair loss are reversible.
So, should you avoid marijuana if you are suffering from male/female pattern hair loss? If you can control your eating habits and suppress stress then the evidence suggests that you should be fine, otherwise you may be better off putting the joint down.