RSO Guide: How to Make Cannabis Oil (RSO – Rick Simpson Oil)

Have you ever found yourself with a bumper crop that you simply cannot smoke all of? Or perhaps your plants were robust, but the flowers lacked bag appeal. These are perfect reasons to consider making RSO – Rick Simpson Oil.

RSO can be used to make very potent edibles, drinks, tinctures, and more. By following this guide you will learn how to make an very concentrated cannabis oil.

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Who is Rick Simpson?

Rick Simpson is a renowned Canadian cannabis activist. His journey with cannabis oil began when he discovered that it helped alleviate his cancer symptoms. This discovery led him to delve deeper into the medicinal properties of cannabis, and he began advocating for its use in treating various medical conditions.
Simpson’s advocacy was not without its challenges. He faced legal issues and even went to prison for sharing his findings about cannabis oil. Despite these obstacles, Simpson remained steadfast in his mission to promote the benefits of what is now known as Rick Simpson Oil, or RSO.

What is RSO?

RSO is a type of cannabis oil that is high in THC, the psychoactive compound in marijuana that provides the “high” sensation. However, Simpson’s focus was not on the recreational aspects of THC, but rather its potential therapeutic effects. He intended his oil to be used as a treatment for a variety of ailments, including chronic pain, cancer, and other serious conditions.
It’s important to note that while many individuals have reported positive effects from using RSO, we are not medical experts and the medical community’s understanding of cannabis and its potential therapeutic effects is still evolving. Always consult with a healthcare provider before starting any new treatment regimen.

Safety First

Remember, alcohol is highly flammable so don’t have any open flames nearby. The alcohol fumes are also flammable so do the distilling process in a well-ventilated area.

Decarboxylation of the flower in a jar has its dangers. Glass can shatter with fast temperature fluctuations. Use weed that is dried and chopped up. Fill the jars only halfway max. Place jars in a cool oven and then turn it on. When completed, turn the oven off and leave jars inside to cool.

Common Problems and Tips

If your oil is not strong, make sure you have decarbed your cannabis. Decarbing turns THCA into THC and greatly increases potency. Inactive oil needs to be heated to transform THCA in THC.

While some people use a slow cooker or rice cooker, the alcohol will be lost to evaporation. Due to the flammable alcohol vapor, it’s strongly advised to try this method outdoors only. Reclaiming the alcohol can save you a lot of money because it can be used over and over again.

Keep the process as cold as possible to limit impurities. Plant material contains more than just THC. Other plant oils and waxes can get into your final alcohol solution. By keeping it cold, they are less likely to.

Required Tools For Making RSO

For this process, you will need:
  • Dried cured cannabis
  • Glass canning jars with lids
  • An oven
  • A very pure solvent such as 99.99% Isopropyl Alcohol
  • Herb Grinder
  • Sieve or colander
  • Cheese cloth
  • Distiller (Amazon Affiliate Link) (or slow cooker with caution)
  • Food grade syringes (like these off Amazon)

The Steps To Making RSO

STEP 1: Prepare and Decarb Cannabis

STEP 2: Freeze Weed and Alcohol

STEP 3: First Wash

STEP 4: Second Wash (Optional)

STEP 5: Add Solution to Distiller

STEP 6: Collect Oil in Syringe

Step by Step Guide

The trick to making RSO is to limit the loss of cannabinoids and terpenes, while also reducing the amount of impurities. Cured cannabis has less chlorophyll, which can taste bad and cause tummy irritation.

STEP 1: Prepare and Decarb Cannabis

Start with dried and cured cannabis that has been milled (chopped up). We are going to decarb it in a jar in the oven. Fill jars halfway with milled flower, seal, and place on the side in a cold oven. Set the oven to 120C or 250F and let it decarb for 45 minutes to 1 hour. Turn off the oven and let it cool slowly inside. Decarbed weed can be stored in the freezer.

What is Decarboxylization? 

Decarboxylation, often referred to as “decarbing,” is a chemical process used to alter the chemical structure of cannabis to make it more potent when consumed in edible form.
In its natural state, cannabis contains a compound called THCA, which is not very psychoactive. Through the process of decarboxylation, THCA is converted into THC, the compound known for its psychoactive effects.
This process does not occur naturally when you consume cannabis through eating. Cooking cannabis at regular cooking temperatures is also not enough to fully decarboxylate it.
Therefore, when preparing cannabis for use in edibles or tinctures, the first step is usually decarboxylation. This process involves subjecting the cannabis to high temperatures, around 250°F or 120°C, for approximately 30-60 minutes.
In simple terms, decarboxylation is like ‘activating’ the cannabis to ensure it has the desired effect when consumed in edible form.

STEP 2: Freeze Weed and Alcohol

Chill the decarbed weed and alcohol in the freezer. You want enough alcohol to fill the jar of decarbed weed. The colder the better, to limit impurities.

When making Rick Simpson Oil (RSO), freezing both the decarbed cannabis and the alcohol is important for a couple of reasons:
Limits Impurities: Keeping the process as cold as possible helps to limit the impurities that get into the final alcohol solution. The cannabis plant contains more than just THC. Other plant oils and waxes can also get into your final alcohol solution if not properly controlled. By keeping the process cold, these are less likely to get into the solution.
Preserves Cannabinoids, Terpenes, and Beneficial Compounds: The freezing process helps to preserve the cannabinoids, terpenes, and beneficial compounds from the whole cannabis plant. This results in a more potent and beneficial final product.
Therefore, the colder the process, the better the end result will be in terms of potency and purity.

STEP 3: First Wash

Pour the ice-cold alcohol into the jar of decarbed weed, give it a shake, and then filter out the plant material with a sieve and cheese cloth.

The “first wash” is a crucial step in the extraction process to create a cannabis tincture. Here’s how it works:

  1. Pour the Ice-Cold Alcohol: The first step involves pouring the ice-cold alcohol into the jar containing decarboxylated (activated) cannabis. The alcohol acts as a solvent, pulling out the active compounds from the cannabis plant, including THC and other cannabinoids.

  2. Shake the Mixture: After adding the alcohol, the next step is to shake the mixture. This helps to thoroughly mix the cannabis with the alcohol and aids in the extraction process.

  3. Filter Out the Plant Material: Once the cannabis and alcohol have been adequately mixed, the next step is to filter out the plant material. This is typically done using a sieve and cheesecloth. The sieve helps to separate the larger pieces of plant material, while the cheesecloth catches any smaller particles.

The liquid that remains after this process is a potent cannabis tincture. It’s important to note that this is just the “first wash.” The used plant material can be washed again to extract more of the active compounds, but the first wash generally yields the most potent results.

What Type of Alcohol or Solvent Can I Use For Making RSO?

For making Rick Simpson Oil (RSO), a highly concentrated cannabis concentrate, the recommended solvent is 99.9% isopropyl alcohol. 
The alcohol will slowly evaporate in the distiller and collect in a container to be used next time. The remaining substance will be a thick, potent cannabis oil that preserves cannabinoids, terpenes, and other beneficial compounds from the cannabis material.
In situations where it’s difficult to find pure solvents, some people have turned to the use of substances such as Everclear, which is about 95% alcohol. However, the remaining 5% is usually water, making Everclear a less effective solvent. After the oil-making process, there will be quite a bit of water left which will need to be evaporated off before the oil is in a finished state.
It’s important to note that using lower proof alcohol or solvents not fit for human consumption is not recommended due to potential health risks and lower effectiveness. Always strive to use the purest solvents possible for the best results.

What Can I Do With The Leftover Plant Material?

The leftover alcohol-soaked plant material from making Rick Simpson Oil (RSO) can still have some uses, although its potency will be significantly reduced after the extraction process. Here are a few possibilities:
  1. Reuse for Second Extraction: You can attempt a second extraction to get any remaining cannabinoids that might not have been extracted the first time.
  2. Make Edibles: Although the potency will be much lower, you can use the leftover material to make cannabis-infused butter or oil, which can then be used in cooking or baking.
  3. Compost It: If you have a garden, the plant material can be composted and used to enrich the soil.
Please remember that the alcohol must be completely evaporated before using the plant material for any of these purposes. Also, it’s important to note that the effectiveness of these methods will vary, as most of the beneficial compounds from the plant material are likely to have been extracted during the initial process.


STEP 4: Second Wash (Optional)

A second wash with the same decarbed can create slightly more oil but there’s a risk of added impurities.

You can store the jar with the decarbed cannabis alcohol solution in the freezer until ready for distilling.

STEP 5: Add Solution to Distiller

Add the alcohol solution to the distiller. The distiller will keep the temperature high enough to evaporate the alcohol but low enough to avoid excessive terpene loss. The distiller will do its thing and collect evaporated alcohol in a jug. Let the distiller cool slightly before opening to avoid getting hit by a cloud of alcohol vapour.

Using a distiller for making Rick Simpson Oil (RSO) has several advantages over using a slow cooker or similar appliances. Here’s why:
Controlled Temperature: A distiller allows for precise control of the temperature. This is crucial in the process of making RSO as it ensures that the alcohol is evaporated at a high enough temperature, but low enough to prevent the loss of beneficial compounds like cannabinoids and terpenes.
Reclaiming the Solvent: The distiller collects evaporated alcohol in a separate container, allowing it to be reused for future extractions. This is not only cost-effective but also environmentally friendly.
Quality of the Resulting Oil: The use of a distiller can result in a highly concentrated cannabis oil that preserves cannabinoids, terpenes, and other beneficial compounds from the whole cannabis plant. This might not be the case with slow cookers or similar appliances, which can generate too much heat and ruin the oil.
Safety: Distillers are designed to safely boil off solvents, reducing the risk of accidents that can occur with open flames or red-hot elements.
However, it’s important to note that distillers can be expensive and require knowledge to operate correctly. Also, in some countries, owning a distiller might be against the law. Therefore, for beginners, it might be more sensible to start with a rice cooker, which also produces decarboxylated oil with full medicinal benefits, and then possibly upgrade to a distiller as they gain more experience and knowledge.

STEP 6: Collect Oil in Syringe

Inside the container, there will be a thick, black, sticky oil. Carefully collect the oil with a syringe and store it in a cool, dark, secure place until ready to use.

The oil is active and can be used immediately without cooking. It can be added to capsules or used in edibles. It’s very strong when active, so a little goes a long way. When adding to a recipe, make sure it is mixed in evenly or you won’t have consistent edibles. It will mix better if it’s warm. Since the oil can get very thick, you can thin it out with something like olive oil or MCT. RSO can also be placed on joints for a little extra oomph.

How Much Weed Do I Need to Make RSO

To produce high quality RSO for medical use, Rick Simpson recommends using a pound or more of dry bud from very potent and sedative medicinal Indica varieties or Indica dominant Sativa crosses, which preferably contain no more than 10% Sativa. Specifically, to perform a full 60 gram or 60 ml oil extraction, you will need 450 to 500 grams of high quality bud material which is completely dry.


Making RSO at home can be a rewarding process, especially when you have an abundance of cannabis that you can’t smoke all of. With the right tools and safety precautions, you can create your own cannabis oil and enjoy its benefits.

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