The cannabinoids CBD (cannabidiol) and THC (tetrahydrocannabinol) can exert different effects either alone or in different portions. The CBD: THC ratio refers to the relative amount of CBD and THC that is contained in any type of cannabis product. The clinical research regarding the therapeutic use of CBD and THC is still relatively young and developing1, but there are some general guidelines that can be used to determine the ratio of CBD: THC that may result in the best desired therapeutic effects for certain conditions. Based on the research provided in this article, the overall guidelines suggest that the following general ratios may prove effective for different types of issues2-7
- When the ratio is relatively equivalent there may be therapeutic effects that can address certain types of pain, nausea, and muscle spasticity. In some individuals anxiety may be reduced with equivalent ratios.
- When the ratio is primarily in favor of THC (e.g., 0:1) the psychoactive effects of THC are more prominent and may result in sedation, increased appetite, and reduction of inflammation. However, individuals may also experience adverse effects such as anxiety, heartbeat irregularities, and even paranoia. Adding CBD into the ratio (e.g., 1:2, 1:3, etc.) may reduce some of the adverse effects.
- Higher ratios of CBD to THC may be most effective in treating psychiatric issues such as depression and anxiety and neurodegenerative diseases like Multiple Sclerosis or Parkinson’s disease.
Looking at the available research regarding specific conditions:
- Equivalent proportions of CBD: THC appeared to provide anti-inflammatory benefits for multiple sclerosis suggesting that this and other neurodegenerative disorders may also benefit from this treatment.2 The use of equivalent ratios also appear to be effective in the treatment of cancer related pain and therefore may be effective in the treatment of other types of pain.3 However, research reviews are still mixed regarding the effectiveness of CBD: THC preparations for treating pain.4
- Higher doses of THC relative to CBD appear to be promising in inhibiting tumor growth.5
- CBD appears to have anticonvulsant properties and in very high ratios of CBD:THC may be effective in reducing seizure activity in children and others.6
- CBD also may have utility in treating depression and anxiety. Higher proportions of CBD to THC (but perhaps not as high as the proportions used in treating epilepsy) have been shown to have promise in treating the symptoms associated with posttraumatic stress disorder (PTSD) suggesting that higher proportions of CBD may be very useful in addressing stress related issues including depression and anxiety.7
The research regarding the effects of various CBD: THC ratios is still in its infancy and there is still much research to be done for a complete understanding of how these cannabinoids work, affect each other, and what their specific medicinal uses will be.8 For instance, a recent review of the research looking at the research regarding the effects of cannabinoid treatment on anxiety suggests that the available research is limited, but promising.9 The review suggests that more controlled studies need to be completed in order to better understand how CBD treatment can affect anxiety. Future research should concentrate on the understanding of the therapeutic ranges of different cannabinoids and the types of pre-existing variables that can guide clinicians to determine the best dosage/proportion of CBD: THC for the specific patient.
- Maccarrone, M., Maldonado, R., Casas, M., Henze, T., & Centonze, D. (2017). Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC: CBD oromucosal spray and others?. Expert review of clinical pharmacology, 10(4), 443-455.
- Kozela, E., Juknat, A., Kaushansky, N., Rimmerman, N., Ben-Nun, A., & Vogel, Z. (2013). Cannabinoids decrease the th17 inflammatory autoimmune phenotype. Journal of Neuroimmune Pharmacology, 8(5), 1265-1276.
- Johnson, J. R., Lossignol, D., Burnell-Nugent, M., & Fallon, M. T. (2013). An open-label extension study to investigate the long-term safety and tolerability of THC/CBD oromucosal spray and oromucosal THC spray in patients with terminal cancer-related pain refractory to strong opioid analgesics. Journal of pain and symptom management, 46(2), 207-218.
- Häuser, W., Fitzcharles, M. A., Radbruch, L., & Petzke, F. (2017). Cannabinoids in Pain Management and Palliative Medicine: An Overview of Systematic Reviews and Prospective Observational Studies. Deutsches Ärzteblatt International, 114(38), 627.
- Śledziński, P., Zeyland, J., Słomski, R., & Nowak, A. (2018). The current state and future perspectives of cannabinoids in cancer biology. Cancer medicine, 7(3), 765-775.
- Vilela, L. R., Lima, I. V., Kunsch, É. B., Pinto, H. P. P., de Miranda, A. S., Vieira, É. L. M., … & Moreira, F. A. (2017). Anticonvulsant effect of cannabidiol in the pentylenetetrazole model: Pharmacological mechanisms, electroencephalographic profile, and brain cytokine levels. Epilepsy & Behavior, 75, 29-35.
- Mizrachi Zer-Aviv, T., Segev, A., & Akirav, I. (2016). Cannabinoids and post-traumatic stress disorder: clinical and preclinical evidence for treatment and prevention. Behavioural pharmacology, 27(7), 561-569.
- McPartland, J. M., Duncan, M., Di Marzo, V., & Pertwee, R. G. (2015). Are cannabidiol and Δ9‐tetrahydrocannabivarin negative modulators of the endocannabinoid system? A systematic review. British journal of pharmacology, 172(3), 737-753.
- Turna, J., Patterson, B., & Van Ameringen, M. (2017). Is cannabis treatment for anxiety, mood, and related disorders ready for prime time?. Depression and anxiety, 34(11), 1006-1017.