Rick Simpson Oil (RSO) concentrate is known for its strength: A recommended serving size is no more than a grain of rice, but can be stronger than other consumption methods. It’s one of the newest concentrates to come to market, first formulated in 2003 by the man after which the product is named. Since its inception, it’s been widely sought after by patients looking for a product that involves no heat and no devices to consume. Read on to learn more
about RSO, how it’s used, and why it may be the right medical marijuana product for you.
Why RSO?

RSO is an odorless and viscous medical marijuana concentrate that’s densely packed with phytocannabinoids like THC and CBD. This thick extract comes in a syringe for ease of measuring and dispensing.
While there are many concentrates on the market, RSO is unique in how it’s consumed. Here’s why RSO may be a good fit for your consumption goals:
• Activated cannabinoids: Unlike other concentrates which require heat to activate, RSO does not need heat. Other types of concentrates contain the acidic
forms of cannabinoids (such as THCA or CBDA) and must be heated to become concentrated vapor[1]. The phytocannabinoids contained within are already activated, so you don’t need an electronic vaporizer to consume this concentrate.
• Flexibility: You can put RSO into food in addition to allowing the measured amount to absorb in your mouth.
• Potent: RSO contains high levels of THC and CBD in varying ratios. High THC RSO could contain up to 90% THC, while high CBD RSO could contain more than 60% CBD. Balanced RSO is also available to consumers who want both phytocannabinoids. For example, the Cresco Harlequin 1:1 RSO Syringe contains
36% THC and 41% CBD.
Although RSO is strong, easy to use, and portable, it may not be the right fit for everyone. You may want to try other products if these points are of issue to you:
• Taste: Some find RSO’s strong flavor to be unpleasant. This is because RSO retains more plant material than other concentrates, lending to a bitter or grassy taste. However, mixing RSO with food or drink at home could mask the flavor.
• Too potent: RSO is so strong that it can be easy to accidentally take too much. Measuring out an amount as small as a grain of rice can be cumbersome for some,
How do you use RSO?

RSO was originally created to be used as a topical. Rick Simpson, after whom RSO is named, applied this activated concentrate directly to his skin. Today, patients use RSO in a variety of ways, including topically, orally by itself or mixed with food, and sublingually (under the tongue).
The most straightforward way to consume RSO is to ingest it directly. Uncap the syringe and place a small amount on a spoon, toothpick, or directly into your mouth. While it’s being absorbed, RSO often ends up making its way into your system biphasically, or in two ways: first through your mouth membranes sublingually, and second through your digestive system. In sublingual consumption, the compounds bypass digestion and more quickly enter your bloodstream, taking effect almost immediately. Any RSO left in your mouth that’s swallowed, or RSO that’s mixed into food at home, is digested before the phytocannabinoids enter your bloodstream and take effect.
You may feel differently if you ingest RSO instead of allowing it to absorb through your mouth. That’s because when RSO is digested, the delta-9 THC is converted in significant amounts to a compound called 11-Hydroxy-THC[2], which is more intoxicating than its precursor. Researchers found that 11-Hydroxy-THC takes effect more quickly and provides a more intense experience than delta-9 THC.
What are your options at the dispensary?
RSO is less common on dispensary shelves than other types of concentrated vapor products like wax or products like medical marijuana flower. But among the several options you’ll find on the dispensary menu, you’ll find some significant differences between them. When choosing an RSO product, it’s important to be aware of a few factors.
• Phytocannabinoid profile: The first, as mentioned above, is the phytocannabinoid content. THC and CBD will likely be the most prominently noted
on the label, but because RSO is a whole plant extract, minor cannabinoids such as Cannabinol (CBN) and Cannabichromene (CBC) are present as well. The
combinations of these phytocannabinoids and the proportions in which they are present can influence your overall experience.
• THC:CBD ratio: If you want a balanced experience, a 1:1 RSO with roughly equal THC and CBD content would be right for you. Alternatively, if you prefer a
stronger experience, an RSO product with higher THC and lower CBD content would be preferable.
• Terpene profile: RSO contains the full spectrum of compounds found within a mature medical marijuana plant, including terpenes. These aromatic and flavorful compounds are thought to offer unique effects of their own, and which terpenes are present in your RSO could influence your consumption experience. For example, if you want RSO to help with pain relief, look for an RSO formula high in terpenes like beta caryophyllene or myrcene.
When choosing an RSO product from the dispensary, be sure to understand the THC to CBD ratio and the compound profile of the product you’re considering. These two indicators can give you an idea whether a particular type of RSO will be effective at meeting your goals.
RSO: A unique medical marijuana product
Although RSO is the “new kid on the block” in many ways, this medical marijuana concentrate is gaining popularity, particularly among the medical community. Not only is a tiny amount more potent than many other products, but its portability and simplicity make it easy to incorporate into your medical marijuana routine. Speak with an Ethos pharmacist to learn more about RSO and how it can be beneficial for your routine.
Sources:
- What is Decarboxylation? https://www.leafly.com/learn/consume/edibles/what-is-decarboxylation
- Δ9-Tetrahydrocannabinol (THC), 11-Hydroxy-THC, and 11-Nor-9-carboxy-THC Plasma
Pharmacokinetics during and after Continuous High-Dose Oral THC: https://pmc.ncbi.nlm.nih.gov/articles/PMC3196989/