FSO vs. RSO: What’s the Difference? [Full Comparison]

Many cancer patients and other therapeutic cannabis users turn to cannabis oils like RSO and FSO for relief when standard treatments fall short.

But what is the difference between FSO and RSO?

Rick Simpson Oil (RSO) is a full-spectrum, high-THC oil that contains all of the plant’s helpful compounds, including the chlorophyll and lipids from cannabis. It’s often used by cancer patients for strong relief.

Full-spectrum Oil (FSO) is a broader term that refers to cannabis oil containing all of the core compounds in cannabis, including cannabinoids, terpenes, flavonoids, and more. It may be high in THC or high in CBD, depending on the formulation, making it similar to RSO but not exactly the same. 

To help you understand the differences better, here is a comprehensive FSO vs. RSO guide.

What is FSO?

“FSO” is a cannabis extract that includes all of the plant’s helpful compounds – cannabinoids, terpenes, flavonoids, phytonutrients, and more.

Unlike isolates or distillates, nothing important is stripped away. FSO can be made from high-THC cannabis or CBD-rich hemp, which means its strength and effects vary. 

In some cases, FSO formulas can closely resemble RSO, while in other cases, they’re different. 

Common reasons people use FSO include pain, inflammation, sleep trouble, and mood support – aside from RSO, it’s perhaps the most beneficial cannabis extract for medicinal use due to the extreme entourage effect its array of compounds deliver. 

What is RSO?

Rick Simpson Oil (RSO) is a cannabis extract with very high THC levels that also includes the helpful compounds in cannabis, including other cannabinoids, terpenes, flavonoids, and even the chlorophyll and lipids from the plant. 

It’s named for Rick Simpson, a Canadian medical cannabis advocate who first used it on his own skin cancer before sharing it widely.

RSO is typically made from indica cannabis strains, which tend to deliver the greatest therapeutic benefit due to their calming properties and high CBD content.

Because of its potent THC levels, cannabinoid variety, and full-plant benefits, RSO is typically used by patients seeking stronger relief, especially those dealing with cancer and cancer-related symptoms like pain, nausea, or loss of appetite.

FSO vs. RSO: Key Differences

FSO vs. RSO: Extraction & Production Method

FSO can be made with several extraction methods, including CO₂, ethanol, or hydrocarbons. These pull cannabinoids, terpenes, and other compounds from the plant. 

RSO is usually made with food-grade ethanol, although it was originally extracted using isopropyl alcohol.

Both processes create a thick, dark oil with cannabinoids, terpenes, flavonoids, and other compounds, with the exact cannabinoid amounts and ratios varying between the two extracts.

FSO vs. RSO: Composition & Cannabinoid Profile

FSO and RSO both deliver broad cannabinoid profiles, but the amounts of specific cannabinoids vary. 

FSO is a category of oils, not one fixed formula, so its cannabinoid ratio can vary a lot depending on how it’s made. Some FSO products are CBD-dominant with only trace THC, while others include more balanced amounts of THC, CBD, CBG, CBN, and other minor cannabinoids alongside terpenes and flavonoids.

RSO is much more specific. It is usually a THC-heavy full-spectrum extract that includes all compounds in the cannabis plant while remaining far higher in THC than most other cannabis oils. 

FSO vs. RSO: Potency & Effects

FSO strength depends on the source. Hemp-based FSO is high in CBD and does not cause a high. Cannabis-based FSO can have moderate to high THC levels. 

RSO is almost always made from high-THC cannabis and often tests at 60–70% THC or more, which gets you high and produces very strong effects.

FSO vs. RSO: Consumption Methods

FSO can be taken under the tongue, added to food or drinks, applied to the skin, or put into capsules. It has a lighter consistency than RSO, so it’s easier to prepare in oils, capsules, or topicals.

RSO is thicker and tar-like, usually dispensed from a syringe for accurate dosing, which is the most common method of using RSO. Because of its strong taste and potency, many patients choose pre-made products such as RSO chews, capsules, or tinctures.

Neither extract should be smoked, vaped, dabbed, or otherwise combusted, as the cannabis compounds they contain like chlorophyll and lipids may create irritating smoke or vapor. 

FSO vs. FSHO (Hash Oil)

If you’re comparing full-spectrum cannabis oils, you might be wondering how full-spectrum hash oil (FSHO) compares to FSO. 

Like FSO and RSO, FSHO keeps a broad range of cannabinoids and other helpful cannabis compounds, but it starts from a different raw material, which changes the texture, flavor, appearance, and overall profile.

Here’s how FSO and FSHO compare:

• Starting Material: FSO is typically made from cannabis flower, while FSHO is made from hash or kief, which are concentrated collections of the plant’s trichomes.
• Plant Matter Content: Because FSO comes from more of the raw plant, it usually contains more chlorophyll, fats, waxes, and other plant material. FSHO contains less of that extra material.
• Texture and Appearance: FSO is often darker, heavier, and more raw, while FSHO is usually lighter in color and smoother in consistency.
• Flavor Profile: FSO tends to have a stronger, more robust plant taste. FSHO often tastes cleaner and smoother because it contains less leftover plant matter.
• Potency: Since FSHO starts with a more concentrated base, it can sometimes feel more potent. FSO, on the other hand, is often valued for keeping more of the broader whole-plant character intact.
• Overall Experience: FSO is usually the better example of a raw, full-plant extract, while FSHO offers a cleaner, more refined full-spectrum oil that still delivers strong cannabinoid and terpene content.

As a result of these differences, FSHO is typically enjoyed recreationally (although some people take it therapeutically), while FSO is most often a therapeutic cannabis product. 

Conclusion: Should You Choose FSO or RSO?

There is significant overlap between FSO and RSO, but they are different. Choose FSO if you’re looking for full-spectrum therapeutic benefits for cannabis for general wellness. RSO, on the other hand, is the best choice for heavy-duty therapeutic and medical uses due to its high THC content. 

No matter which extract you choose, look for lab-tested products from reputable companies with good reviews so you’ll have the best experience. 

Want to see how Rick Simpson Oil stacks up against other popular options on the market? Check out our other detailed breakdown guides:

• FECO vs RSO
• RSO vs CBD
• RSO vs Distillate

FSO vs. RSO: Frequently Asked Questions

Here are some questions our customers frequently ask us about the differences between FSO and RSO.

Is FSO Stronger Than RSO?

High-THC FSO may be similar in strength to RSO, but in many cases, RSO is stronger than FSO due to its higher THC content.

Is RSO The Same As FSO?

Not exactly, but they are very similar. RSO usually refers to a full-spectrum cannabis oil made with a heavy, whole-plant extraction style. FSO stands for full-spectrum oil, which is a broader term for oils that keep a wide range of cannabinoids and compounds intact. 

What Is Stronger Than RSO Oil?

High-potency concentrates like THC distillate, THCA diamonds, or certain isolate-heavy extracts can test stronger by THC percentage. That said, stronger on paper does not always mean stronger in effect, since RSO often feels heavier because it contains more cannabinoids and plant compounds.

How Strong Is FSO?

FSO is usually considered very strong. It is a concentrated oil, so even a small amount can have noticeable effects. Exact strength depends on the product’s THC or CBD content and whether it is formulated for recreational or therapeutic use. It also depends on the quality of the product which is why you should shop with us or another reputable brand.

Can You Put FSO In A Joint?

Yes, but carefully. You can add a small amount to a joint, usually by dabbing a thin line inside or outside the paper or mixing a little into the flower. Too much can make it burn unevenly and waste product.

How Much FSO Should I Take?

Start very small, especially if it is high in THC. A rice grain-sized amount is the common beginner starting point, and some people start with even less. Wait several hours before taking more so you do not overdo it.

Does RSO Get You Stoned?

Yes, if it contains a meaningful amount of THC, RSO can absolutely get you stoned. It is often much stronger and heavier-feeling than standard flower or lower-dose edibles.

Is FSO Better Than Distillate?

It depends on what you want. FSO is usually better for people who want a fuller cannabinoid profile and a more rounded effect. Distillate is better if you want high THC, a cleaner-tasting product, or something more neutral for formulation. FSO tends to feel more full-bodied, while distillate feels more stripped down.