What Is Full Spectrum RSO? The Truth About Rick Simpson Oil

What Is Full Spectrum RSO? The Truth About Rick Simpson Oil

We tell you all about full spectrum RSO, the cannabis product also known as Rick Simpson Oil – and why cbdMD doesn’t sell it, even though it’s popular.

If you are a CBD shopper, you might have come across some CBD vendors advertising oils with names like Full Spectrum RSO, RSO Full Spectrum, and that sort of thing. The “full spectrum” part of it might sound familiar if you’ve seen full spectrum CBD products, but what does the “RSO” mean?

RSO stands for Rick Simpson Oil, named after the person who first invented it 17 years ago. He became something of a celebrity in the world of medical cannabis, writing a book and creating a documentary touting his invention before being sidelined by a stroke in 2018. Yet he never patented it, which is why multiple vendors of CBD and other cannabis-related products sell what they call “full spectrum RSO” oils.

But we don’t have full spectrum RSO here at cbdMD, for several good reasons. To understand why not, read on.

Who Is Rick Simpson?

Rick Simpson is a Canadian who started using medical marijuana decades ago to help him handle the long-term effects of a head injury. In 2003, he got a few spots on his arm that turned out to be basal cell carcinoma, a type of skin cancer.

Researching the subject, Simpson noticed a study indicating that THC helped shrink tumors in mice. So he created a super-potent cannabis oil – by his account, it’s 80 to 90 percent THC – by washing cannabis buds in a solvent and boiling it down to a thick substance. He put some on his spots, he covered them with a bandage, and eventually, his carcinoma disappeared.

After that experience, Simpson started evangelizing the oil to the rest of the world. He didn’t actually sell it – as noted, he did not patent the substance, he included instructions for how to make it at home on his website, and he even gave it away for free (though that might partly be for legal reasons we will get to later). But what exactly is in the stuff?

What Is Full Spectrum RSO?

The term “full spectrum” is one that you see a lot in the CBD and cannabis industry. We explained in more detail what full spectrum means in a previous post, but the short version is that it describes hemp extract that includes the widest possible range of cannabinoids, terpenes, amino acids, and other nutrients from the plant.


A man standing outside while the sun is rising with cannabis plants growing outside around him


In industry parlance, this most especially signals that the extract has some amount of THC in it. This is important both to customers and for legal reasons. At the federal level in the United States, no product of hemp can be legally sold if it has more than 0.3 percent THC. And while less than 0.3 percent THC is not going to get you high, it could get you in trouble if drug testing is part of your life. If it isn’t, though, many people feel that full spectrum extract yields better results.

As mentioned earlier, full spectrum RSO has way, way more THC than that. That makes it quite different from any CBD oil because THC is its main focus – whatever CBD is in there is strictly a supporting player. Because of full spectrum RSO’s homemade and unregulated nature, though, the exact percentage may vary by quite a bit. And in fact, if you find an online vendor selling “full spectrum RSO” or “Rick Simpson Oil,” it could be virtually anything. Simpson, in fact, openly disclaimed any other products being sold under his name for that very reason.

Which brings us to the next point: why we don’t sell it.

The Problems with RSO Full Spectrum

Here at cbdMD, we like to be as transparent as possible about our products, how we make them, and what’s in them. We also try to help you to spot CBD scams. And while Simpson himself seems to be a true believer in his oil, there are two troubling signs about the whole RSO phenomenon that should make you wary.

It’s Based on Huge, Unproven Claims

Here on our website, we like to tout benefits of CBD like everyday stress management, improved sleep, and support for exercise recovery. But over-the-counter CBD has not been approved to prevent or treat any disease, and the FDA frowns on promoting anything as a treatment for a disease that hasn’t been approved for it. It frowns especially hard on claims about cancer.

But what does it mean to be an approved treatment? It means that the substance has been through an extensive testing process, involving many human beings in rigorously controlled trials that account for other possible factors that might influence the disease. Only then does the FDA offer its seal of approval.

This is where Simpson’s process runs into problems. He read a promising study on mice – but mouse physiology is different from human physiology, so that doesn’t really tell us if it works on people, only that it should be studied in people. Simpson experimented on himself, and his cancer went away – but cancers sometimes go away on their own, especially if they’re in the early stages. So how do we really know if the oil did anything?

That’s why properly designed clinical trials have so many people in them. One person whose condition improves after taking a substance could be a coincidence but multiply that by hundreds or thousands, and it looks more like an actual effect. Moreover, clinical trials also count people whose condition doesn’t improve – something that reliance on personal testimonials often misses.

That’s not to say for certain that full spectrum RSO doesn’t work. But it would be irresponsible to claim with any confidence that it does. Simpson escaped FDA scrutiny by not selling his oil for profit, but in 2018 he did get a sternly worded letter from the founder of the International Association for Cannabis as Medicine calling him out for making sketchy claims, showing a general lack of knowledge about cannabis, and discouraging people from seeking more conventional treatment.

“That you present things wrongly by not understanding chemistry, physiology, and medicine is not what I hold against you,” wrote Dr. Franjo Grotenhermen. “One doesn’t necessarily need to understand all the details. However, this is a question of life and death, and such a serious issue, that you have to be accused of not living up to your responsibility and therefore your own aspirations.”

Full Spectrum RSO Is Illegal in Many Locations

As noted earlier, to be federally legal in the United States, a cannabis product can have no more than 0.3 percent THC content. Full spectrum RSO, by definition, has a whole lot more than that. And in fact, that’s why Rick Simpson himself stopped giving away his oil through his website because he was running afoul of legal authorities. He left up instructions for making it, but even making RSO full spectrum at home is illegal in many states.

You can sometimes get pre-made full spectrum RSO at dispensaries in states that have legalized marijuana. But since e-commerce is a national or even global business, and most e-commerce companies don’t especially want to get busted by the FBI, what they’re selling as full spectrum RSO is likely to just be full spectrum CBD oil, with a very tiny amount of THC.

As we’ve said, full spectrum CBD oil has benefits. And research is continuing to discover exciting new applications for CBD, THC, and other cannabis compounds. But you shouldn’t expect it to cure cancer.

Using Cannabis Products Responsibly

So now that we’ve poured a bunch of cold water on the full spectrum RSO phenomenon, that might sound pretty discouraging in terms of using cannabis products in general. And it’s true that in this still mostly unregulated space, you have to be a savvy shopper to make sure you’re getting good products and have realistic expectations for their results. But fortunately, you can achieve that with a few simple steps.

Always Talk to Your Physician First

It’s true that the medical world hasn’t always been that friendly to cannabis, but things have changed in recent years. Physicians are getting more and more knowledgeable about CBD and other cannabis products, and your doctor can likely give you some firsthand advice about whether full spectrum RSO, CBD oil, or other types of cannabis oil can benefit you.

It’s also good to talk to your doctor because the effectiveness of some types of medications can be reduced by taking CBD and other cannabinoids. So if you’re taking any medicines already, you should find out if they’re on that list. Plus your physician should know whether you’re taking CBD if he or she is going to prescribe you anything.


cbdMD full spectrum cbd oil 2000mg softgels bottle with spectral colors below it


Find Out Exactly What’s in the Products

As we said earlier, anybody can slap “full spectrum RSO” on their product, because there are no enforceable standards about what that means. That’s true of a lot of things in the cannabis world, unfortunately. So the best way to know what’s in the products is to carefully read the labels – and if a company doesn’t provide a detailed label, don’t buy it.

Some things to look for: Which cannabinoids are in the product? Is there any THC in it? How much? If a company is being really transparent, it will provide lab test results for each batch of its products with these details, along with information about any heavy metals or other pollutants that might turn up in the hemp extract.

Knowing where the extract comes from is also helpful. To be federally legal, all cannabis products in the U.S. have to come from industrial hemp, which must have no more than 0.3 percent THC by dry weight. I don’t know if it’s even possible to get real full spectrum RSO out of that, but probably not. However, that way you know the product you’re buying is legal.

If you’re in a state that has legalized marijuana, you can indeed legally buy products of marijuana and not just hemp, so you stand a chance of finding real full spectrum RSO. But you’ll probably have to go to an approved dispensary to get it.

Avoid Extravagant Claims

Let’s say it once more for the people in the back: No cannabis products you can buy online or over the counter are approved to treat any disease. There are a few derivatives of cannabis, like Marinol and Epidiolex, that are approved as medicines, but they are manufactured by specific companies and are only available by prescription (and for quite severe conditions).

So any company selling CBD or any other cannabis product as a disease treatment is breaking the law, and therefore not trustworthy. The explosion of startups in this space has meant that the FDA hasn’t always been able to stay on top of things, so don’t assume that just because a company has managed to stay online, it’s not doing anything wrong.

All of this isn’t to say that you shouldn’t try full spectrum RSO. It’s unlikely to hurt you (though making it at home has certain dangers since it involves flammable solvents), and it could help. But make sure you get it at the right place, and that you know what you’re getting into.