If you’ve spent any time researching medical cannabis, you’ve probably come across Rick Simpson Oil. It’s one of the most talked-about cannabis extracts on the internet, and for good reason.
RSO is incredibly potent, it’s been used by patients managing everything from chronic pain to cancer-related symptoms, and it looks nothing like the vape carts or gummies you might be used to seeing at a dispensary.
But RSO also comes with a lot of confusion attached to it. You might see it confused with FECO, wonder what a legitimate label should include, or come across products using the RSO name without following the original formula.
This guide walks you through what RSO actually is, how it compares to other extracts, what to check before you buy, and where you can find a trustworthy product.
What Is RSO?
RSO stands for Rick Simpson Oil, named after Rick Simpson, a Canadian engineer and cannabis advocate who developed the extract in the early 2000s. After treating his own skin cancer with a homemade cannabis oil, Simpson began sharing his extraction method for free, and it eventually became one of the most recognized names in medical cannabis.
RSO is a whole-plant extract, which means it retains far more of the cannabis plant’s natural compounds than a typical oil or tincture. That includes THC, CBD, terpenes, flavonoids, and even chlorophyll, which is part of why RSO looks thick, dark, and almost tar-like compared to other cannabis products. It’s traditionally made using isopropyl alcohol or naphtha as a solvent to strip cannabinoids from the plant material, though many modern producers use food-safe alcohol instead for a cleaner final product.
Because of how concentrated it is, RSO typically contains a high percentage of THC, often somewhere between 60% and 90%. That’s a big part of why dosing starts small. If you’re trying RSO for the first time, you’ll usually want to start with a rice-grain-sized amount and gradually increase as you learn how your body responds.
It’s worth being clear about one thing upfront: while RSO has a passionate following and plenty of anecdotal success stories, there isn’t strong clinical evidence that it cures cancer or any other serious illness. Many patients use it alongside their existing treatment plan for symptom relief, not as a replacement for medical care, and that’s a conversation worth having with your doctor before you start.
RSO vs. Other Cannabis Extracts
RSO gets grouped together with a handful of other extracts pretty often, and while they share some traits, the differences matter once you’re deciding what to actually buy.
RSO vs. FECO
FECO stands for Full Extract Cannabis Oil, and you’ll often see it used almost interchangeably with RSO. The main distinction comes down to solvent and process. RSO traditionally uses isopropyl alcohol or naphtha and is produced at higher temperatures, while FECO relies on food-grade ethanol or CO2 at lower temperatures.
This difference is important because ethanol extraction tends to preserve more terpenes and is generally considered safer for oral use, since any residual solvent is food-grade to begin with. Neither one is objectively better than the other: choosing between RSO and FECO really comes down to how you plan to consume the cannabis and how the product was made.
RSO vs. THC Oil
Standard THC oil, like the kind used in vape cartridges or tinctures, is usually a refined distillate. That means most of the plant’s other compounds have been stripped away, leaving behind a specific, measured concentration of THC. RSO takes the opposite approach. It’s unrefined whole-plant extract, so you’re getting THC alongside CBD, terpenes, and everything else naturally present in the cannabis.
If you’re looking for a precise, predictable dose with minimal plant material, refined THC oil is probably a better fit. If you want the broader therapeutic profile that comes from the whole plant, RSO is the stronger option.
RSO vs. CBD Oil
CBD oil is typically made to minimize or completely remove THC, which makes it non-psychoactive and legal in far more places. RSO is the opposite end of the spectrum, built around high THC content specifically because that’s what many patients are seeking for stronger symptom relief.
If psychoactive effects are something you want to avoid, CBD oil is the safer starting point. If you’re managing more severe symptoms and your doctor has cleared you for higher-THC products, RSO offers a level of potency that CBD oil simply isn’t designed to provide.
What to Look for on an RSO Label
Not everything sold as RSO online is actually RSO, so the label matters more than you might expect. Start by checking for third-party lab testing. A trustworthy product should have a Certificate of Analysis available, either on the packaging or the brand’s website, confirming cannabinoid content and screening for residual solvents, pesticides, and heavy metals. If a company can’t produce a COA, that’s a red flag.
Next, look at how the product describes its extraction method. Quality RSO should note whether it’s made from ethanol, isopropyl alcohol, or another solvent, and it should be full-spectrum, not a THC distillate dressed up in RSO branding. Also pay attention to whether it’s made from actual THC-rich cannabis or from hemp. Some products marketed as RSO are made from hemp and contain minimal THC, which puts them in a completely different category from the original formula, even if the label uses the same name.
Finally, check the THC percentage listed. Authentic RSO usually falls somewhere in that 60% to 90% range. If a product claims to be RSO but lists a fraction of that potency, you’re likely looking at a diluted or mislabeled version.
Types of RSO Products
While oral syringes containing pure oil is the way Rick Simpson originally stored and consumed his RSO, there are many more product formats available today.
- Syringes: Still the classic format and remain popular for people who want direct control over their dose.
- Capsules: Have become a common alternative for anyone who wants consistent, pre-measured servings without dealing with the syringe’s texture directly.
- Gummies and Other Edibles: Offer a more palatable route, which matters given how strong and bitter raw RSO can taste.
- Tinctures: Give you a middle ground between the syringe and an edible, since you can take them sublingually or mix them into food or drinks.
- Topicals and Suppositories: Round out the category for patients focused on localized relief or looking for options with fewer psychoactive effects, since neither method sends much THC into the bloodstream the way oral consumption does.
Best RSO Brands
With so many sellers marketing products as RSO, sourcing from a brand that actually follows the traditional formulation is the most important decision you’ll make before buying.
RickSimpsonOil.com
RickSimpsonOil.com stands out as the top option here, and the depth of their product selection is why.
Instead of treating RSO like a side product, this company built their entire catalog around it. That means you’ll get authentic, full-spectrum oil extracted from high-THC cannabis sativa strains, not the hemp-based or distillate substitutes that pop up under similar branding in dispensaries and online.
Their lineup covers syringes in 1g, 5g, 10g, 15g, 20g, and 30g sizes, along with capsules, gummies, tinctures, topicals, and suppositories, so you can pick a format that actually fits how you want to take it.
Every product ships with third-party lab testing covering potency and safety, and RickSimpsonOil.com also ships internationally with discreet packaging, which matters for patients who need reliable access regardless of where they live.
Emerald Bay Extracts
Emerald Bay Extracts takes a different approach by leaning heavily into strain-specific full-spectrum syringes instead of offering one universal blend.
Their lineup includes options across indica, sativa, hybrid, CBD, and CBG categories, with named strains like Super Lemon Haze, OG Kush, Gelato 41, and Cannatonic giving you more flexibility to shop by cannabinoid content or strain preference. T
The syringes use medical-grade hardware with clear markings that make dosing easier to manage, which is a big advantage if you’ve struggled with awkward syringes from other brands.
All in all, Emerald Bay is worth considering if you want RSO tailored to a specific effect rather than a single high-THC formula.
Treeworks
Treeworks stands out for patients who want the deeper, full-spectrum effects of real RSO without settling for one generic high-THC oil.
Instead, the brand builds its formulas around specific goals, offering daytime blends, sleep-focused options with CBN, and gentler CBD-rich formulas depending on what you’re managing. That flexibility matters if you’re taking RSO medicinally, since a nighttime formula with CBN feels very different from a daytime option built around CBG or THCV.
If you like the idea of real RSO but want it matched more closely to your daily routine, Treeworks is a brand worth exploring.
Skagit Organics
Skagit Organics focuses entirely on RSO instead of treating it as a side product. Based in Washington State, they only extract RSO using organic food-grade alcohol, avoiding butane and other hydrocarbon solvents to preserve a cleaner, more complete terpene profile.
Their lineup goes much deeper than a single formula, with options including THC-dominant Original RSO, premium CBD RSO in various CBD-to-THC ratios, and CBG and CBN variants aimed at different needs like focus, sleep, or nervous system support. Products are available as syringes and strain-specific capsules, and Skagit Organics runs its own testing protocols on top of DOH-compliant standards.
If you want RSO from a Washington-based company with a track record (voted best RSO in the state at the 2023 NW Leaf Bowl) and a cannabinoid-specific product range, Skagit Organics is a solid option.
Momenta (Trulieve)
Momenta is Trulieve’s in-house RSO brand, and it’s a good fit if you’re a Florida medical patient wanting strain-specific full extract cannabis oil (FECO) rather than one universal formula.
Their syringes come in Indica, Hybrid, and Sativa options, each preserving the cannabinoid and terpene profile of its specific cultivar rather than blending everything into a single generic extract.
That gives you more control over the experience, whether you want calming, energizing, or balanced effects, while still getting the full-spectrum benefits RSO is known for.
Because Momenta is sold exclusively through Trulieve’s Florida dispensary network, it’s not an option if you’re shopping outside the state, and availability can vary store to store. But for Florida patients who want strain-driven RSO from one of the largest medical cannabis providers in the country, Momenta is a dependable option.
Is RSO Legal?
This is where things get more complicated than most people expect. Because authentic RSO is made from high-THC cannabis rather than hemp, its legality follows the same rules as cannabis in general, and those rules vary significantly depending on where you live.
In states with legal medical or recreational cannabis programs, RSO is legal to purchase and use, typically through a licensed dispensary or a retailer that ships within state lines. In states without legal cannabis programs, RSO remains illegal to buy, sell, or possess, regardless of how it’s marketed online. Federally, cannabis-derived RSO is still classified as a controlled substance, and crossing state lines with it, even between two states where cannabis is legal, isn’t permitted.
You’ll also see hemp-derived versions of RSO marketed as a legal alternative, since hemp products with 0.3% THC or less are federally legal under the Farm Bill. Just know that these products won’t deliver the same effects as traditional high-THC RSO, since the entire therapeutic profile that made RSO popular comes from that higher THC content.
Before buying anything, it’s worth checking your state’s current cannabis laws and talking to your doctor about whether RSO makes sense as part of your treatment plan.
Bottom Line
RSO isn’t like the polished, precisely dosed products you’ll find in most dispensary display cases, and that’s part of its appeal. Whether you’re a medical patient or a recreational consumer, if you want whole-plant extract with a lot of potency behind it, there’s no better cannabis product than RSO.
The tradeoff is that you need to be more careful about where you buy it, since the market has plenty of products labeled as “RSO” without the formulation to back it up.
Check for lab testing, confirm the extraction method, and understand your state’s cannabis laws before you order. And, if you’re looking for a brand that checks every one of those boxes, know that RickSimpsonOil.com remains one of the most consistent, transparent options available today.
Frequently Asked Questions
Does RSO cure cancer?
There’s no clinical evidence that RSO cures cancer, despite the anecdotal stories that helped popularize it. Some patients use it for symptom relief alongside conventional treatment, but it should never replace medical care without your doctor’s guidance.
How much RSO should I take as a beginner?
Most new users start with a rice-grain-sized amount, roughly the size of a half-grain of rice, taken a few times a day, and increase gradually as they learn how their body responds. RSO is extremely potent, so starting small matters more than it does with most other cannabis products.
Can I buy RSO if I don’t have a medical card?
It depends on your state. In states with recreational cannabis programs, adults 21 and older can typically buy RSO without a medical card, while states with medical-only programs usually require a valid recommendation.
What’s the difference between RSO and a regular THC tincture?
RSO is a whole-plant, full-spectrum extract that retains far more cannabinoids and plant compounds than a standard tincture, which is usually made from refined THC distillate. That makes RSO significantly more potent and gives it a broader therapeutic profile.
