Type II Chemotype (Mixed THC/CBD Cannabis)
The mixed-cannabinoid chemotype produces roughly balanced THC and CBD from a heterozygous BT/BD genotype at the cannabinoid synthase locus.
Type II isn't a terpene — it's a chemotype, a chemistry classification based on the THC:CBD ratio in the flower. We're filing it here because it sits next to terpene chemistry in any honest discussion of what's actually in a plant. The science is solid: chemotypes were defined in the 1970s and confirmed genetically. What's oversold is the idea that 'balanced' THC:CBD automatically equals a gentler or more medicinal high. The ratio matters, but dose, individual response, and minor cannabinoids all shape what you feel.
What a chemotype actually is
A chemotype is a way of sorting cannabis plants by the cannabinoids they produce, regardless of how the plant looks or what people call it commercially. Ernest Small and H. D. Beckstead proposed the original three-chemotype scheme in 1973 after analyzing hundreds of accessions: Type I is THC-dominant, Type II carries similar amounts of THC and CBD, and Type III is CBD-dominant [1] Strong evidence. Later work added Type IV (CBG-dominant, lacking the downstream synthases) and Type V (essentially cannabinoid-free fiber hemp) [2] Strong evidence.
Type II specifically refers to plants whose flowers contain THCA and CBDA in roughly comparable quantities — most researchers use a THC:CBD ratio between about 0.5 and 2.0 as the working definition, though cutoffs vary by paper [3] Strong evidence. The 'mixed' label is genetic: these plants are heterozygous at the cannabinoid synthase locus, carrying one BT allele (encoding THCA synthase) and one BD allele (encoding CBDA synthase). Both enzymes compete for the same precursor, cannabigerolic acid (CBGA), so the plant ends up making both acidic cannabinoids [4] Strong evidence.
The genetics in one paragraph
Etienne de Meijer and colleagues showed in 2003 that THC:CBD ratio in cannabis segregates as if controlled by a single locus with two co-dominant alleles, BT and BD [4] Strong evidence. BT/BT plants are Type I, BD/BD plants are Type III, and BT/BD heterozygotes are Type II. Subsequent sequencing showed that BT and BD are actually tightly linked but distinct genes (THCAS and CBDAS) rather than true alleles, with non-functional pseudogene copies complicating the picture [5] Strong evidence. The practical upshot is the same: cross a reliable Type I with a reliable Type III and the F1 generation will be Type II.
Where you'll encounter Type II flower
Type II chemotypes were rare in the illicit market through the late 20th century because breeding selected aggressively for THC. They re-entered the legal market through medical programs that valued CBD content. Cultivars consistently reported as Type II in chemical analyses include:
- Cannatonic — often tests around 1:1 THC:CBD, the genetic backbone of many later balanced cultivars Strong evidence
- Harlequin — frequently reported in the 5:2 CBD:THC range, sitting at the Type II / Type III border Weak / limited
- Pennywise, Sweet and Sour Widow, Argyle, and various CBD Critical Mass lines Anecdote
Lab-reported ratios for any given branded strain vary widely between growers and harvests, so the chemotype label is more reliable than the strain name. GW Pharmaceuticals' nabiximols (Sativex) is produced from two proprietary chemovars — one Type I and one Type III — blended to deliver an approximately 1:1 ratio, which is effectively a manufactured Type II profile [6] Strong evidence.
What the human evidence actually shows
This is where honesty matters. Several reasonable hypotheses about CBD modulating THC's effects have mixed human support:
CBD reducing THC-induced anxiety and psychotomimetic effects. Some controlled human studies have found that CBD attenuates THC's anxiogenic and psychotomimetic effects, but other well-designed studies have not, and the effect appears dose-dependent and may even reverse at low CBD doses [7][8] Disputed.
Nabiximols for MS spasticity. The strongest clinical evidence for a balanced THC:CBD product is for nabiximols in multiple sclerosis spasticity, where it is approved in numerous countries based on randomized trials [6] Strong evidence. This does not automatically generalize to smoked or vaporized Type II flower at unknown doses.
'Entourage' claims. The popular claim that balanced THC:CBD produces a qualitatively different, more therapeutic high than THC alone is plausible and partially supported pharmacologically, but the human data are thinner than the marketing suggests [9] Weak / limited.
What is clear: at matched THC doses, Type II flower delivers meaningful CBD, and CBD has its own pharmacology (5-HT1A partial agonism, weak CB1 negative allosteric modulation, effects on FAAH and adenosine signaling) [10] Strong evidence. What is unclear: whether a given consumer at a given dose will notice a difference.
Type II vs. the other chemotypes
Quick orientation, so the label means something:
- Type I — THC-dominant, CBD essentially absent. The standard recreational profile.
- Type II — mixed, the subject of this article.
- Type III — CBD-dominant, THC under ~0.3–1%. Most legal hemp flower.
- Type IV — CBG-dominant; the plant lacks functional THCAS and CBDAS so CBGA isn't converted downstream [2] Strong evidence.
- Type V — near-zero total cannabinoids, found in some fiber hemp accessions [2] Weak / limited.
Chemotype is independent of the indica/sativa morphology debate and independent of terpene profile. A Type II plant can smell like anything — citrus, pine, fuel, gas — depending on its terpene synthase alleles, which segregate separately from the cannabinoid synthases.
Practical notes for consumers
If you're choosing Type II flower, ignore the strain name and read the certificate of analysis. A 1:1 product at 8% THC / 8% CBD behaves very differently from a 'balanced' product at 18% THC / 6% CBD, which is barely Type II and will hit much closer to a Type I experience. Effects at low doses (single inhalations, 2.5–5 mg oral THC equivalents) are subtle; effects at high doses are still psychoactive — CBD does not 'cancel out' THC, despite what dispensary folklore sometimes claims Disputed.
Sources
- Peer-reviewed Small, E. & Beckstead, H. D. (1973). Common cannabinoid phenotypes in 350 stocks of Cannabis. Lloydia, 36(2), 144–165.
- Peer-reviewed Mandolino, G., Bagatta, M., Carboni, A., Ranalli, P. & de Meijer, E. (2003). Qualitative and quantitative aspects of the inheritance of chemical phenotype in Cannabis. Journal of Industrial Hemp, 8(2), 51–72.
- Peer-reviewed Hillig, K. W. & Mahlberg, P. G. (2004). A chemotaxonomic analysis of cannabinoid variation in Cannabis (Cannabaceae). American Journal of Botany, 91(6), 966–975.
- Peer-reviewed de Meijer, E. P. M., Bagatta, M., Carboni, A., Crucitti, P., Moliterni, V. M. C., Ranalli, P. & Mandolino, G. (2003). The inheritance of chemical phenotype in Cannabis sativa L. Genetics, 163(1), 335–346.
- Peer-reviewed Weiblen, G. D., Wenger, J. P., Craft, K. J., ElSohly, M. A., Mehmedic, Z., Treiber, E. L. & Marks, M. D. (2015). Gene duplication and divergence affecting drug content in Cannabis sativa. New Phytologist, 208(4), 1241–1250.
- Peer-reviewed Russo, E. B. & Guy, G. W. (2006). A tale of two cannabinoids: the therapeutic rationale for combining tetrahydrocannabinol and cannabidiol. Medical Hypotheses, 66(2), 234–246.
- Peer-reviewed Englund, A., Morrison, P. D., Nottage, J., et al. (2013). Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment. Journal of Psychopharmacology, 27(1), 19–27.
- Peer-reviewed Haney, M., Malcolm, R. J., Babalonis, S., et al. (2016). Oral cannabidiol does not alter the subjective, reinforcing or cardiovascular effects of smoked cannabis. Neuropsychopharmacology, 41(8), 1974–1982.
- Peer-reviewed Russo, E. B. (2011). Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. British Journal of Pharmacology, 163(7), 1344–1364.
- Peer-reviewed Britch, S. C., Babalonis, S. & Walsh, S. L. (2021). Cannabidiol: pharmacology and therapeutic targets. Psychopharmacology, 238(1), 9–28.
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