How to Convert THC Delta 9 to THC Delta 8

Delta-9-Tetrahydrocannabinol (THC)  is a naturally occurring isomer of THC found in cannabis plants.  It’s psychoactive effects are well known.  While delta-9-THC is the most abundant isomer of THC, there is interest in the lesser studied delta-8-THC isomer.


IUPAC Naming Convention

Detla 9 THC and other isomersThe diagram below has numbered positions on the top left ring structure.  If the double bond is at the 9 position then the molecule’s name is delta-9-THC.  If the double bond is at the 8 position the molecule’s name is delta-8-THC.


The molecule pictured is delta-8-THC for example.



The reaction

Delta-8-THC isomer can be made from Delta-9-THC in a spinning band distillation system.  Mix in 4% acidic alumina silicate with your extracted and winterized crude cannabis oil.  Distill the cannabis oil and collect the THC distillate as you normally would.  The combination of the acidic alumina silicate and boiling flask heat will catalyze the the rearrangement of the THC molecule from delta-9 to delta-8-THC.

The effect

Delta-8-THC is said to give a less intense and longer lasting high than the delta-9 isomer.  Some are experimenting with different ratios of delta-8 to delta-9.  If you have tried delta-8-THC, let us know about your experience!


Warning – Lawyer Stuff

Use this information at your own risk.  Please use some common sense if you want to try this.  Find and SOP from a trusted source.  Don’t make your first attempt with a large batch of crude extract ($$$).  It may take a number of tries to perfect the technique.  Experiment with small batches that won’t break you if they fail.  Move up in batch size as your skill level and confidence increase.




  1. Thanks for the great blog and valuable information.

    Can I trouble you for help on the brand and item number you used for acidic alumina silicate?

    This would really help me.


    1. Dear Joe Schutz,

      You can get acidic alumina silicate from your friend in Woodland 🙂


  2. Hello,

    I’m a Army Combat Veteran with TBI, PTSD and tons of hardware now in my back. Is there any studies how it helps with TBI and PTSD?

    Also, could you please provide me with step by step instructions (recipe) on producing/extracting Delta 8 for vape pens, equipment needed, where to get the equipment, brand and item number of the solvents used?


    1. Hi,

      I do not have any evidence for its efficacy for specific conditions. Delta 8 does have a measured lower psychoactivity and anecdotally I have heard/read about people claiming it produces less paranoia and the other effects of an intense high.

      If you are interested in a start to finish process, you may be best off hiring a consultant. On this topic I really only know enough to get myself in trouble. I travel to many labs (and run many distillations), but I do not do this day in day out to know all the specifics.

      Here are some places to start:



  3. Hi there! Thank you for sharing! What is the *typical* conversion percentage and yield?
    Example: you start with 555g of D9 distillate at 90% thcD9 potency.
    You run the D8 rxn, filter, rotovap and distill the resulting distillate.
    How much D8 distillate do you have at the end and what is the %D8 in the distillate? 50%D8 and 40%D9 ? Higher % D8 ?
    Looking forward to hearing back from you!
    -Andrew Gumbiner
    IG: aggumbi


    1. Hi,

      The after distillation yield tends to be about 90-95%. High conversions (80%+ D8) are possible on cleaner material and with better reagents. My first attempt netted me about 15% D8 and 80% D9 from 85% starting material. Minimizing side reactions is important which is why higher cannabinoid material is preferred.



  4. Hello, if my cannabis oil is made from thcv, will the conversion be delta 8 thcv? Thank you.


    1. Hi,

      I am willing to bet yes. There was a study I read where the goal was to make CBN-v from THC-v which was successful. The ‘v’ in THCv is far away from where the reaction is happening so it shouldn’t really have an effect.


  5. Hi,
    My distalit has been converting to Delta 8, with and with out the alumina. Why would it be doing so without the alumina. I am looking to keep my distalit as delta 9. Any advice would be greatly appreciated.
    Thank you


    1. Hi,

      Other than a reaction with something in your boiling flask, the other possibilities are heat and time. If your runs take 10+ hours and you need to do multiple passes, even lower temps have the potential to cause conversion.

      If your distillation machine requires temps in excess of 220-230 C, you will see much more rapid degradation. Instead of trying to increase the temperature to distill, try achieving a deeper vacuum (lower pressure). This will decrease the boiling points of everything and remove oxygen.


Leave a Reply

Your email address will not be published. Required fields are marked *