The Hidden Link Between Obesity and Marijuana

Marijuana's uncanny ability to make you feel hungry has long intrigued the medical community. What most people may not know is that marijuana's biochemical effects in our brains have helped to inform us about potential mechanisms to control appetite using pharmacotherapies.

May 18, 2014 at 8:03AM

Marijuana's uncanny ability to make us feel hungry has long intrigued the medical community. Currently, many states allow marijuana to be prescribed for its therapeutic benefits, especially for patients who have trouble drumming up an appetite.

The link between marijuana use and appetite has also informed us about potential ways to treat the growing obesity epidemic. And this particular use of marijuana may surprise you.

Cannabinoid receptors as an anti-obesity drug target
Because of the link between appetite and the cannabinoid receptor system, clinicians have been attempting to exploit it as a way to combat the growing obesity epidemic. The idea is simple enough: Create a drug that acts as an antagonist for the cannabinoid receptors in our brain, causing us to feel full instead of hungry.


Source: Sanofi.

While the concept is straightforward in theory, its application in the real world has proved difficult. In 2008, the French drugmaker Sanofi (NYSE:SNY) pulled its cannabinoid antagonist Acomplia in Europe after the drug was found to be associated with serious psychiatric effects, including a handful of suicides. The problem is that the cannabinoid receptor system also influences mood through cascading effects that are difficult to control. As a result, we've seen researchers move away from cannabinoid receptors as therapeutic targets in recent years, although hope remains that a second generation of drugs can target cannabinoid receptors outside the brain to avoid the unwanted emotional side effects.  

Moving on to the serotonin receptor system
Because of these adverse effects associated with stimulating the cannabinoid receptor system, researchers have been looking into a highly similar biochemical pathway known as the serotonin receptor system. These receptors also tend to be G-Protein-coupled receptors and show a high distribution in the hypothalamus as well.

Arena Pharmaceuticals (NASDAQ:ARNA) successfully developed an obesity med using this system recently, gaining Food and Drug Administration approval for its 5-HT2C agonist lorcaserin in 2012. Like Acomplia, lorcaserin promotes weight loss by making a person feel full, causing the person to eat less. While clinical trials showed that lorcaserin is a moderately effective weight-loss pill, some researchers have nonetheless raised the specter of potential serious psychiatric effects in this drug as well. Although we haven't seen evidence of any major side effects with lorcaserin since the drug's commercial launch, its relatively slow uptake into the obesity market is perhaps at least partially explained by safety concerns stemming from obesity drugs past. 


Source: Eisai Pharmaceuticals.

Foolish wrap-up
Doctors are hoping to one day have access to a safe and effective pharmacotherapy for chronic obesity. And despite promising insights from the cannabinoid receptor system, the sheer complexity of the human nervous and endocrine systems has blunted our best efforts so far.

Looking ahead, there is reason to believe that some pharma companies could reprise their efforts to develop an obesity med that targets the cannabinoid receptor system. Namely, recent work has shown that cannabinoid receptors are more widely distributed than previously thought, raising the potential to target them in tissues outside the central nervous system, hopefully lessening their influence on a person's mood. Besides the potential commercial implications, there are therapeutic reasons to go this route as well. Specifically, preclinical studies in rats have shown that a dual stimulation of the cannabinoid and serotonin pathways leads to a synergistic effect that appears to modify feeding behavior. In short, we could one day see lorcaserin used in conjunction with a next-generation cannabinoid receptor in the fight against obesity. 

That being said, pharma companies haven't exactly been lining up to develop new cannabinoid receptor-based obesity meds. In 2008, Merck (NYSE:MRK) shuttered one of the last efforts by a large pharma following problematic psychiatric effects arising in its clinical candidate taranabant. Whether these recent insights into cannabinoid receptors and obesity will prove enough to entice a company to follow up remains to be seen. Understand, however, that the field hasn't been entirely abandoned and progress is being made on how to best exploit this system without altering a patient's mental state. 

Will this stock be your next multibagger?
Give us five minutes and we'll show how you could own the best stock for 2014. Every year, The Motley Fool's chief investment officer hand-picks one stock with amazing potential. But it's not just any run-of-the-mill company. It's a stock perfectly positioned to cash in on the upcoming year's most lucrative trends. Last year his pick skyrocketed 134%. And previous top picks have gained upwards of 908%, 1,252% and 1,303%! You don't want to miss what could be his biggest winner yet! Just click here to download your free copy of "The Motley Fool's Top Stock for 2014" today.


George Budwell has no position in any stocks mentioned, and neither does The Motley Fool. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.

Money to your ears - A great FREE investing resource for you

The best way to get your regular dose of market and money insights is our suite of free podcasts ... what we like to think of as “binge-worthy finance.”

Feb 1, 2016 at 5:03PM

Whether we're in the midst of earnings season or riding out the market's lulls, you want to know the best strategies for your money.

And you'll want to go beyond the hype of screaming TV personalities, fear-mongering ads, and "analysis" from people who might have your email address ... but no track record of success.

In short, you want a voice of reason you can count on.

A 2015 Business Insider article titled, "11 websites to bookmark if you want to get rich," rated The Motley Fool as the #1 place online to get smarter about investing.

And one of the easiest, most enjoyable, most valuable ways to get your regular dose of market and money insights is our suite of free podcasts ... what we like to think of as "binge-worthy finance."

Whether you make it part of your daily commute or you save up and listen to a handful of episodes for your 50-mile bike rides or long soaks in a bubble bath (or both!), the podcasts make sense of your money.

And unlike so many who want to make the subjects of personal finance and investing complicated and scary, our podcasts are clear, insightful, and (yes, it's true) fun.

Our free suite of podcasts

Motley Fool Money features a team of our analysts discussing the week's top business and investing stories, interviews, and an inside look at the stocks on our radar. The show is also heard weekly on dozens of radio stations across the country.

The hosts of Motley Fool Answers challenge the conventional wisdom on life's biggest financial issues to reveal what you really need to know to make smart money moves.

David Gardner, co-founder of The Motley Fool, is among the most respected and trusted sources on investing. And he's the host of Rule Breaker Investing, in which he shares his insights into today's most innovative and disruptive companies ... and how to profit from them.

Market Foolery is our daily look at stocks in the news, as well as the top business and investing stories.

And Industry Focus offers a deeper dive into a specific industry and the stories making headlines. Healthcare, technology, energy, consumer goods, and other industries take turns in the spotlight.

They're all informative, entertaining, and eminently listenable. Rule Breaker Investing and Answers are timeless, so it's worth going back to and listening from the very start; the other three are focused more on today's events, so listen to the most recent first.

All are available for free at

If you're looking for a friendly voice ... with great advice on how to make the most of your money ... from a business with a lengthy track record of success ... in clear, compelling language ... I encourage you to give a listen to our free podcasts.

Head to, give them a spin, and you can subscribe there (at iTunes, Stitcher, or our other partners) if you want to receive them regularly.

It's money to your ears.


Compare Brokers