Learn how to isomerize or convert CBD into THC (delta 8 or delta 9 THC).
The process for converting CBD (cannabidiol) to delta 8 THC isn’t alchemy or magic. In fact, it’s much less complicated than you might expect — but there are some dangers and precautions that need to be taken very seriously.
This guide covers the basic principles used for making Δ8 THC from CBD — including a handful of specific recipes to follow from professional chemists.
CBD + Acid + Time = Δ8 THC
The conversion process from CBD to delta 8 or delta 9 THC is actually pretty simple and will take place on its own when subjected to the right environment.
However, the chemicals needed to catalyze this reaction are caustic and it’s possible to inadvertently create toxic byproducts in the process.
We advise against converting CBD to delta 8 unless you have a proper lab setting and have a strong background in organic chemistry. This guide is intended for educational purposes only.
If you’re looking for delta 8 THC, it’s better to buy it from companies that employ professional chemists that know how to make delta 8 THC safely.
Here are the potential risks for making delta 8 THC:
The compounds needed to convert CBD to Δ8 THC include highly caustic and poisonous acids and solvents. Some of these acids can even evaporate into the air without you even knowing it. If you don’t know how to work with these chemicals safely or have access to the high-tech (and expensive) lab equipment to perform the reaction — you may be placing yourself or others at considerable risk.
Secondly, this process can be finicky. Meaning that if you add too much or too little acid, don’t conduct proper testing, or use products that aren’t pure — you may inadvertently create any number of unwanted and unknown byproducts. It’s common for these byproducts that form to have toxic or carcinogenic (cancer-causing) side effects.
Everything you use has to be pure — or the risk of contaminants and byproducts goes up substantially. It can be nearly impossible to determine all the different byproducts if you’re not working with pure ingredients. This includes the starting CBD material and the solvents, acids, and washes used throughout the process.
There are instructions online for ways to convert CBD to delta 8 that use chemicals picked up at your local hardware store — but this is extremely dangerous. These chemicals are not lab-grade, which means they aren’t completely pure. When you run reactions with these solvents or acids you run a high risk of creating potentially dangerous byproducts.
The final warning is that this conversion process isn’t always 100% accurate. Oftentimes you’ll end up with a mixture of delta 8 THC, delta 9 THC, and other compounds or cannabinoids. Unless you perform the necessary THC remediation (also risky), you may end up with a product that contains illegal concentrations of delta 9 THC.
Please don’t attempt this reaction unless you already have a lot of chemistry experience, access to adequate safety and lab equipment, and take all the precautions involved with safety (AKA, you have the ability to test the reaction throughout the process).
The short answer is yes — but there’s a bit of room for interpretation.
The long answer is much more complicated, but there’s a strong case to be made that delta 8 THC is legal — with the exception of a few states that have their own laws banning all forms of THC, including delta 8. These states include Alaska, Arizona, Arkansas, Colorado, Delaware, Idaho, Iowa, Montana, Pennsylvania, and Utah.
The current consensus is that delta 8 THC products are legal — as long as they adhere to these two criteria:
This is the primary reason why the standard practice for making delta 8 THC products involves the conversion of CBD rather than using delta 9 THC as the starting point. Any products made from delta 9 THC from marijuana are considered a Schedule I drug and are only legal in states that have their own recreational marijuana laws (with the exception of the legal states Alaska, Arizona, and Colorado).
(Short Path Distillation)
This method is safer than the more advanced methods (especially for non-chemists), is relatively cheap to get started, but less efficient (in terms of both cost and yield).
When deciding what process to use, you can basically choose to prioritize two out of three advantages:
You can’t have all three.
This is the best option for hobbyists looking to try the delta 8 THC conversion process at home (caution advised). It works for converting both CBD and delta 9 THC into delta 8 THC.
Always send a sample of your final product to a lab to confirm the contents. You should never consume unknown chemicals for any reason. While unlikely, it’s always possible for toxic or carcinogenic byproducts to form in your solution if you’re not careful.
This method was outlined in a video by WKU Consulting.
Begin by adding the T41 to the boiling flask that comes with the distillation kit. You should add around 100 grams for every 5 liters of crude oil you’re going to convert.
Next, add the crude and gently warm everything until it’s all mixed together.
The goal is to get the contents of the flask to 205ºC, where it will be boiling and evaporating through the condenser. But you don’t want to just jack the temperature up to this temperature. It’s not going to heat the contents evenly. The key to getting this right is to start at a low temperature (10 C) and increase very gradually by 10 degrees until you get to the target temperature.
There are going to be three different fractions we’re going to separate out.
Allow the liquid to start collecting in the first flask. The first fraction (heads) will be very light-colored and watery.
The saying is that “if it drips, it’s no good — if it coils, it’s oil.”
Basically, once the extract that’s condensing starts to thicken up and form coils as it falls into the flask, you’re into your main fraction — which is the part we want to keep.
As soon as this happens, change to a fresh flask to collect the main fraction.
When the mains are finished, the extract will start to become thick and dark. This is the tails fraction. There are lots of unwanted elements in here, so you’ll want to change the flask again to avoid contaminating the main fraction you’ve collected.
Tails can be reprocessed later to clean it up in future batches, so it’s still worth collecting.
If you have a thermometer in your reflux column, you can use this to tell what fractions you’re extracting more accurately:
This method is super simple (as far as organic chemistry goes) and pretty difficult to mess up.
However, it’s vital you test your final sample to make sure there were no contaminants or nasty byproducts made in the final extract. It’s also helpful to know exactly what you’re working with and what your final yield was.
The risks of this setup are unknowingly forming toxic byproducts, contaminating your mains fraction with solvents, or producing high concentrations of delta 9 THC — which may or may not be legal where you live.
The reactor method is the process used by the vast majority of large-scale operations because it’s much more efficient and scalable than the short path distillation method. This process optimizes for cost and efficiency but at the sacrifice of safety.
Short path distillation is still used later in the process to purify the extract and separate the delta 8 THC from other cannabinoids.
This process is quite simple — at least, in theory. There are a lot of subtleties involved that require the experience of a professional chemist and some very sensitive lab and testing equipment to get right.
I need to remind you again not to do this if you don’t work in a lab alongside highly experienced chemists.
This method is derived from the information included in a patent outlining the conversion of CBD to delta 9 and delta 8 THC using lewis acids, as well as a community-driven attempt to standardize the process and create an SOP from the wise folks on the Future 4200 forum.
The reactor method requires a fair bit of lab equipment and very high-purity acids and solvents. Here’s a list of the most common equipment and materials needed to perform this reaction:
Isomerization works best on isolates or distillates. Crude extract will create a ton of nasty byproducts when the acid is added, some of which are completely toxic.
While there are people that report getting high yields of delta 8 THC from a crude extract, these are also highly skilled chemists who have access to precision testing equipment so they can test samples throughout the process.
Most experts agree it’s best to use pure CBD isolates only when running delta 8 THC isomerization.
There are lots of different solvents to choose from when making delta 8 THC. The role of the solvent is to convert the solid CBD into a liquid for the reaction to take place.
The main difference between the conversion of CBD to delta 8 THC compared to delta 9 THC is the presence of water. If water is present, it will lead to a higher delta 8 concentration — so solvents like toluene that allow for some water to dissolve in the mixture can help increase efficiency.
Likewise, if looking to make delta 9 THC, solvents that have little to no moisture will produce a better yield. An example of this would be anhydrous heptane.
A strong acid is used to facilitate the conversion of CBD into THC. The types of acid used, along with the amount of moisture allowed to remain in the system is what determines whether the CBD will convert primarily into delta 8, delta 9, or delta 10 THC.
No reaction is 100% efficient, which means you’re going to get a little bit of each in the final product. Generally speaking, Lewis acids that are not also Brønsted acids work for converting CBD to delta 9 THC, while Brønsted acids work for converting CBD to delta 8 THC.
Common catalysts for the conversion of CBD to delta 8 THC in order of popularity:
Most companies use pTSA because it’s safe and cost-effective but not as efficient as other methods (meaning the reaction will also make delta 9 THC and CBN).
Once you’ve selected your acid, mix it into the CBD and solvent mixture (amount varies, but usually around 10%). Now you’ll need to leave the mixture on a stirring plate. Some recipes call for using room temperature; others add heat. Either way, it’s going to stay here for the next 3–18 hours.
You’ll need to continually test the solution until you get the ratios of delta 8 to delta 9 THC you’re expecting. Once this is reached, or the levels of delta 8 THC start to decrease, stop the reaction by neutralizing the acid.
Neutralizing and removing the acid requires several washes using sodium bicarbonate (or another neutralizer), distilled water, and brine water.
Washes are usually added at a ratio of 1:1 and shaken up in a separation funnel. Give the mixture time for the aqueous and organic phases to separate. Remove the aqueous phase and repeat with the next wash.
There are lots of opinions on what the best way to do this part is, but here’s a general recipe to put it into context:
Four wash cycles:
It’s important to test a sample after the fourth wash to make sure there are no detectable levels of the acid. If there is, keep repeating the washing process until it’s no longer detected.
The next step is to remove the solvent. The easiest and most efficient way of doing this is with a machine called a rotary evaporator. This machine is basically a glass chamber that’s gently heated and put under vacuum to force all the volatile solvent to evaporate from the solution — leaving behind pure cannabinoids.
What you should be left with at this point is delta 8 THC, delta 9 THC, a little bit of CBD that didn’t convert, and potentially some CBN or delta 10 THC.
Test this sample to confirm this is the case. If something went wrong in the previous steps, you didn’t use pure chemicals, or you haven’t fully removed all the acid from the mixture, you’re going to get compounds that appear on the test that either aren’t what you expected or are unable to be identified at all.
If this happens, you should stop the reaction and consult a chemist. It’s out of the scope of this guide to offer a solution because the compounds you’ve created could be virtually anything. It’s nearly impossible to know exactly what contaminants you’ve created without a high level of understanding of organic chemistry and some high-tech lab equipment.
Now that you know you’re working with pure cannabinoids, you’ll need to remove the rest of the delta 9 THC. This is done through a process called THC remediation.
THC remediation is most often done to comply with legal requirements. The THC content is usually removed completely with a technique called chromatography. Other times it’s put through additional chemical reactions to convert it into legal cannabinoids like CBN instead.
When making delta 8 THC extracts, the logical move is to convert any remaining delta 9 THC into the delta 8 isomer. This is done through a process called isomerization.
Isomerization is the process of converting one isomer into another — such as delta 9 to delta 8 or vice-versa.
It’s easier to make delta 8 from delta 9 THC than it is to make delta 8 from CBD. The conversion is already a natural process (unlike the conversion of CBD to THC), but there are ways to make the reaction faster and more efficient.
Here’s the process in a nutshell:
The extract is placed in a spinning band distillation system and mixed with acidic alumina silicate (4%) with heat applied. After several hours, virtually all the delta 9 THC will have converted to delta 8.
The final product is then distilled using short path distillation or wiped film distillation to isolate the delta 8 THC from CBD, CBN and other impurities.
Testing is important at every stage of production. Every step of this process runs the risk of creating unwanted byproducts. You will have no idea these byproducts were created unless you test. The sooner you catch them, the easier it will be to identify and remove them.
Many of the byproducts that could be created are toxic or carcinogenic.
It’s important to perform multiple kinds of tests on the final sample and understand exactly what’s inside the final product.
The process outlined above covers the basic principles. But here are a few simplified examples of what professional chemists are using in their labs:
This was a submission in the Future 4200 forum community delta 8 THC Isomerization SOP.
This was another suggestion by a user for the community SOP in the Future 4200 forum. Some of the details have been modified for clarity:
This method was outlined in a video posted by WKU Consulting:
This process for CBD isomerization to THC was outlined by a user on an old chemistry forum:
CBD is converted to THC through a process called cyclization — which creates a ring structure in the CBD molecule that essentially turns it into THC.
The reaction is a cyclization (addition) reaction to the terminal alkene (H2C=) coming off the CBD molecule from the adjacent O-H group on the phenyl ring .
The acid then protonates the H2C= group, and it gets attacked by the O-H group to form THC.
Depending on the process and chemicals used, different ratios of delta 8, delta 9, or delta 10 THC will form.
High heats, or long durations of time can also lead to higher levels of breakdown products and other minor cannabinoids, such as CBN.
These different types of THC are differentiated by the placement of a chemical bond in the newly formed ring structure:
We’ve used several technical terms in this article to describe the process taking place when converting CBD to THC. Here’s a quick breakdown of some key terms related to the creation of delta 8 THC.
Isomerization is a term used to describe the conversion of a molecule into a different isomer of the same molecule. There are several different isomers of THC. They all have the same chemical formula, but the molecular structure is slightly different.
The delta 9 THC isomer is characterized by the placement of a double bond at the ninth carbon chain. During isomerization, this double bond is moved to the eighth carbon chain — thus converting the molecule into the delta 8 isomer of THC instead.
Lewis acids and Brønsted acids are chemicals that can be used to catalyze reactions. They donate electrons and protons (H+) to influence or change the structure of a given molecule.
Lewis acids tend to be better at converting CBD to delta 8 THC, while Brønsted acids tend to be better for converting CBD to delta 9 or delta 10 THC (there are exceptions to this rule).
|Lewis Acids||Brønsted Acids|
Alumina (acid washed)
Alumina-silica (acid washed)
Magnesium silica (acid washed)
|Hydrochloric acid (HCL)
Glacial acetic acid
Refluxing is the process of evaporating, and recondensing a volatile substance into a liquid which drops back into the flask. It’s used to heat compounds to perform a particular type of reaction without losing all the solvent through evaporation.
This technique is used to boil substances for hours or days at a time without losing significant volume.
Reflux columns are used to continually evaporate, condense, and evaporate substances over and over again until it finally reaches the top of the column. This is done to ensure only the compounds with the highest volatility are evaporated from the starting liquid.
A molecular sieve is a porous material that allows only molecules of a certain size to enter the pores. It’s used to remove certain types of molecules from a solution that have a distinctly different size than other molecules in the solution.
A common use for molecular sieves in the formation of delta 8 THC is to remove water molecules from the solution.
Short path distillation is a technique that involves boiling a substance to evaporate the volatile components which then travel down a short condensing tube. The condensing tube is cooled in order to cause the volatile substance to transition from a gas, back to a liquid.
This technique is used with compounds that are unstable at high temperatures.
Short path distillation is an effective method for separating CBD and other cannabinoids from THC.
This is an advanced distillation technique that involves the formation of a thin film of a substance over a surface that’s exposed to gentle heating and low pressure to evaporate various compounds from the surface.
It’s often used to remove solvents and separate CBD from THC or other cannabinoids during the manufacturing process.
THC remediation is the process of removing THC from a cannabis extract in order to increase the purity of CBD or other individual cannabinoids or to comply with legal requirements when manufacturing CBD or delta 8 THC products.
In some cases, the THC is removed using chromatography techniques, or it’s converted into other cannabinoids with the help of chemical catalysts.
If you plan to convert CBD to THC yourself, we highly recommend you reach out to a chemist to help you through the process if you aren’t familiar with one of the techniques outlined above — especially if you’re looking to get into the delta 8 THC space from a production perspective.
You should always hire a professional to perform this reaction, and spend the time and money to test every sample properly.
With that said, here are the most common questions we’ve received on the conversion of CBD to delta 8 THC.
If you’re interested in trying delta 8 THC, check out the distillates, tinctures, gummies, and vape cartridges offered by brands like Area 52. They’re affordable, high-quality, and come with all the necessary testing to prove they’re pure.
Both delta 8 and delta 9 THC are different isomers (versions) of the THC molecule. The only difference is the location of a double bond in the chemical structure. Delta 8 has this bond at the eighth carbon chain, while delta 9 THC has this bond at the ninth position.
There are also delta 2, delta 3, delta 6, delta 7, and delta 10 THC isomers possible.
Delta 8 THC has a similar psychoactive effect profile as delta 9, but much more subtle. It’s considered to be about half as potent and has a much more sedative or relaxed effect profile. Many people prefer delta 8 because it’s less likely to make you feel paranoid or anxious, it’s much better for promoting hunger and sleep, and is a powerful anti-nausea agent.
There’s a lot of misinformation going around about the color of delta 8 THC distillates. Some companies are shipping pinkish or yellowish extracts, others are sending cloudy or perfectly clear distillate.
In general, clear extracts are associated with purity, but it’s also completely possible for a pink-colored or yellow-colored extract to have near perfect purity. The clarity of the extract just depends on the compounds used to make it, and how it was distilled.
Cloudy extracts are usually a warning sign for impurities, but could also form if the delta 8 THC starts to form crystals. If you leave clear delta 8 THC in storage for long periods of time it may turn cloudy — but this doesn’t mean it’s gone bad.
Ultimately, you can’t gauge the purity of delta 8 distillate from the color alone. It’s better to rely on the lab reports to determine purity.
The boiling point of delta 8 THC is 383.5°C.
If you’re interested in this topic and want to learn more or pursue a career in cannabis extraction, check out the training programs offered by Trichome Institute, Green Flower, or Precision Extraction Solutions.
For hobbyists, there are lots of great instructional videos on YouTube to get started.
Delta 8 THC is a naturally occurring compound produced in both hemp and marijuana. However, the plant makes very little of this substance on its own. So little, it’s not viable for a manufacturer to extract delta 8 THC naturally from the plant.
Instead, various techniques are used to facilitate the conversion of CBD into delta 8 THC through a process called isomerization.
This process is actually pretty straightforward as far as organic chemistry goes, but should never be attempted by anyone without a strong understanding of chemistry or access to a lab.
If errors are made, low-grade materials are used, or proper testing isn’t performed, the sample can become contaminated.
While some of these byproducts are harmless, others are toxic.
It’s best to leave the creation of delta 8 THC to the professionals. If you want to try delta 8 THC, look for brands that offer the full range of tests to prove the purity of their products.