Cannabis Strains Explained: What Patients Should Know

Introduction

If you have spent any time reading about medicinal cannabis online, you have probably run into a familiar set of terms: “strains”, “indica”, “sativa”, “hybrid”, and long lists of names that seem to promise very specific effects. It is understandable that patients start there. That language is everywhere, and it makes medicinal cannabis sound as if the main job is simply picking the right strain.

In practice, that is not how prescribing works in Aotearoa. Under the Medicinal Cannabis Scheme, medicinal cannabis products are prescription-only and must meet minimum quality standards before supply. They also come in a range of formulations. For patients, the more useful question is usually not “Which strain should I choose?” but “What product profile might make sense given my medical history, current medicines, and what my doctor thinks is appropriate to explore?”

Medically Reviewed by Dr. William Parkyn

Chemovars, cultivars and strains: what is the difference

“Strain” is the term most people recognise, but it is largely a consumer term rather than a precise medical one. In plant science and horticulture, the preferred word is often cultivar, which the Intellectual Property Office of New Zealand describes as a contraction of “cultivated variety”. That is one reason you increasingly see “cultivar” or “variety” used in formal and regulatory contexts instead of “strain”. In fact, New Zealand’s own medicinal cannabis guidance refers to cannabis cultivars in the context of cultivation licences.

There is also a second word that matters in medicinal contexts: chemovar. A cultivar describes the cultivated plant line, while a chemovar describes its chemical profile. That makes chemovar especially useful for medicine, because two cannabis products can share a familiar market label yet still differ in the balance of cannabinoids and terpenes that may influence how they are experienced and prescribed. Researchers have argued for years that the broader field should move away from vague vernacular naming and toward classification based on measurable chemistry instead.

This distinction matters because patients are often exposed to “cultural” language while clinicians must work with “chemical” language. One influential metabolomics paper described a large gap between the way patients talk about cannabis and the way scientists study it, noting that labels such as sativa and indica tend to carry broad assumptions that biochemistry has not reliably confirmed. So while “strain” may still appear in everyday conversation and search results, it is not the most precise way to think about a medicinal product.

Indica vs sativa vs hybrid: what patients need to know

The indica, sativa and hybrid categories are deeply embedded in cannabis culture. Many people have heard a simple rule of thumb: indica means calming or sedating, sativa means uplifting or energising, and hybrid sits somewhere in between. The problem is that modern evidence does not support using those labels as reliable predictors of effect, especially in a medical setting.

A 2021 Nature Plants study analysed more than 100 cannabis samples with both chemical profiling and genome-wide genotyping and found that sativa and indica labelled samples were genetically indistinct on a genome-wide scale.¹ What the labels did seem to track was variation in a smaller number of terpenes associated with aroma, not a clean underlying split between two biologically separate categories. In other words, the labels may reflect fragments of aroma chemistry and consumer expectation more than a dependable taxonomy.

Other genetic work has reached a similar conclusion. A Frontiers in Plant Science study found no clear distinction between sativa, hybrid and indica subcategories within drug-type cannabis.² More recent work has continued to argue that a classification based on terpene patterns or broader chemical fingerprints is more meaningful than the old three-part label system.

That is one reason the classic shorthand can mislead patients. A product labelled “indica” does not automatically mean it will feel sedating, and a product labelled “sativa” does not automatically mean it will feel stimulating. Those expectations may still persist culturally, but they are too blunt to guide prescribing. Even genetically identical plants can show significant differences in cannabinoid and terpene profiles when grown in different environments, which means the name alone tells you much less than people assume.

For patients, this is a useful reset. If you have previously tried to make sense of medicinal cannabis by memorising “daytime strains” and “night-time strains”, it may help to think of those labels as loose folklore rather than a dependable clinical system. In medicine, oversimplified labels are not enough. What matters is what is actually in the product, how it is formulated, and how your own body responds to it over time.

THC, CBD, and terpenes: why chemical profiles matter

When doctors think about medicinal cannabis, they are not relying on whether a label sounds calming or upbeat. They are looking first at the chemical profile of the product. In New Zealand, the medicinal cannabis minimum quality standard is designed to give prescribers confidence in quality and consistency, and official guidance identifies active ingredients such as THC, CBD, their acidic forms, and other cannabis-derived ingredients present above stated thresholds.³ The point is not branding. It is knowing, as accurately as possible, what the patient is actually taking.

The two cannabinoids patients hear about most often are THC and CBD, and they are not interchangeable. THC is the cannabinoid most associated with the intoxicating or “high” feeling people connect with cannabis, and it is also more closely linked to adverse effects such as dizziness, sedation, and changes in thinking or perception. CBD does not produce that same feeling, but it is still pharmacologically active and can interact with other medicines through enzyme pathways involved in drug metabolism. That is one of the reasons doctors look beyond the general idea of “cannabis” and pay close attention to cannabinoid content, dosing, and the rest of a patient’s medication list.

Terpenes are the third part of the picture, and they are where the indica/sativa shorthand most clearly breaks down. Terpenes are the aromatic compounds responsible for the distinctive smell of different flowers, and individual terpenes have been studied for their own pharmacological actions. Beta-caryophyllene, for example, binds directly to the CB2 receptor and has been investigated for anti-inflammatory and analgesic effects; linalool, the terpene associated with lavender, has anxiolytic activity in preclinical models that appears to run through the same GABA pathways targeted by some sedative medicines; myrcene is commonly linked to sedation; and limonene has the strongest human evidence so far. A 2024 double-blind study found that vaporised d-limonene given alongside THC significantly reduced THC-induced anxiety and paranoia in healthy adults, compared with THC alone.⁴ This is one of the first controlled human demonstrations of the long-discussed “entourage effect” — the idea that cannabinoids and terpenes act together rather than in isolation.

Crucially, what seems to matter is not the presence of any single terpene but the relative composition of terpenes within a given flower. Two products can carry the same market name, or the same indica/sativa label, yet have quite different terpene ratios — and it is that ratio, layered on top of the cannabinoid content, that may help explain why patients report different experiences from products that look identical on a shelf. This is precisely the kind of measurable, reproducible information that a strain name cannot convey.

It is important to be honest about the strength of this evidence. Outside the limonene work, most terpene findings come from laboratory and animal studies rather than large clinical trials, and a 2023 review of the entourage effect concluded that the human data remain limited and, in places, contradictory.⁵ So the responsible position is a measured one: terpene profiles can be clinically relevant and are worth considering, but a terpene label is not a guarantee of a specific outcome, and the science is still maturing.

This is why the industry is moving toward chemical classification. A better patient question is not “What strain is this?” but “What is the THC and CBD profile, and what do we know about the terpene profile?” In some settings, chemovar-based classification may ultimately prove more useful than strain names because it tells clinicians something measurable and reproducible. That approach fits the way medicines are actually evaluated: by composition, consistency and patient response, not by folklore.

Medicinal cannabis prescription: what your doctor assesses

Aotearoa’s Ministry of Health is clear that medicinal cannabis products are only available on prescription, and that health professionals are best placed to decide whether a medicinal cannabis product is suitable for someone. That assessment includes talking through medical history, reviewing other medicines, and weighing up possible risks and benefits. This is important because medicinal cannabis is not a one size fits all category. It spans different formulations and different cannabinoid balances, and some products sit within the controlled drugs framework.

In practice, a prescribing doctor is usually thinking about several layers at once. The first is whether medicinal cannabis is appropriate at all. The second is the formulation. In New Zealand, the available forms of medicinal cannabis include dried cannabis material and pharmaceutical dosage forms such as tablets, capsules and oral liquids, and dried products may be prescribed for use as tea or through a medical vaporiser rather than smoking. That matters because formulation shapes how the product is used in daily life and how treatment can be monitored and adjusted.

The third layer is the product’s cannabinoid profile and how cautiously any medicine should be introduced. International consensus guidance for THC containing products generally emphasises starting low and adjusting gradually, reflecting the fact that tolerability and adverse effects vary from person to person. This is another reason strain labels are not very useful clinically. A doctor is not choosing a product because it sounds like a classic indica or sativa. They are thinking about cannabinoid content, likely sensitivity, the person’s wider circumstances, and whether any plan can be adjusted safely over time.

This is also where the terpene profile becomes part of what experienced prescribers describe as the “art” of prescribing. Because the cannabinoid content alone does not always explain why two similar products feel different to a patient, some clinicians do factor the terpene composition of a flower into their thinking — for example, leaning toward a more sedating terpene profile for a patient whose main issue is sleep, or being mindful of profiles that an individual patient has tolerated poorly before.

This is a matter of clinical judgement rather than firm protocol, precisely because the scientific evidence for individual terpene effects is still weak and largely preclinical. A careful prescriber holds both ideas at once: terpenes are worth considering and may help personalise a choice, but they are not a substitute for monitoring how the individual patient actually responds.

Doctors also have to think about safety and interactions. CBD, for example, can interact with a number of other medicines, and THC-containing products bring different considerations around sedation, cognition and impairment. In New Zealand, prescribing of verified medicinal cannabis products is product-specific, and brand substitution cannot occur without the prescriber’s explicit authorisation because, for unapproved medicines, one brand cannot simply be assumed equivalent to another. That is a powerful reminder that product selection is a clinical decision, not a matter of browsing names on a list.

How to discuss medicinal cannabis with your doctor

A lot of patients begin with the question, “Which cannabis strain should I ask for?” It is a completely understandable starting point, but it is not usually the most helpful one. Strain language is familiar because it is simple, searchable and built into years of cannabis culture. The difficulty is that it can create false confidence. Names feel precise even when they are not.

A better question is: What product profile might make sense for me, and why? That shifts the discussion from labels to the things that actually matter in a prescription setting: the formulation, the cannabinoid balance, the terpene composition where it is known, your other medicines, your prior experience, and how a treatment would be started and monitored. It also keeps the conversation where it belongs, which is with a prescriber rather than with internet strain lists or broad popular stereotypes. Official New Zealand guidance makes this point plainly: medicinal cannabis is prescription-only, and health professionals are the ones expected to assess suitability and weigh risks and benefits.

That does not mean patient observations are irrelevant. On the contrary, how you describe your symptoms, routines, sensitivities and previous experiences can be very useful.

But the role of that conversation is not to match you to a catchy strain name. It is to help your doctor decide whether medicinal cannabis is appropriate, which type of product is worth considering, and how to review your response safely and realistically.

For patients, that is probably the most practical takeaway. You do not need to become an expert in strain names to explore medicinal cannabis. You only need enough understanding to know that the old indica, sativa, and hybrid shorthand is limited, that cultivars and chemovars (and the terpene composition behind them) are more useful ways of thinking about medicinal products, and that higher THC is not automatically better than lower THC.

The most important decision is not choosing a strain yourself. It is having the right conversation with a prescriber who can assess what, if anything, might be appropriate for your situation.

Frequently Asked Questions

References

1. Watts S, McElroy M, Migicovsky Z, et al. Cannabis labelling is associated with genetic variation in terpene synthase genes. Nat Plants. 2021;7(10):1330–1334. https://www.nature.com/articles/s41477-021-01003-y

2. Schwabe AL, Hansen CJ, Hyslop RM, McGlaughlin ME. Comparative Genetic Structure of Cannabis sativa Including Federally Produced, Wild Collected, and Cultivated Samples. Front Plant Sci. 2021;12:675770. https://pmc.ncbi.nlm.nih.gov/articles/PMC8544287/

3. Ministry of Health. Medicinal cannabis products that meet the minimum quality standard. https://www.health.govt.nz/regulation-legislation/medicinal-cannabis/information-for-health-professionals/minimum-quality-standard-medicinal-cannabis-products

4. Spindle TR, Zamarripa CA, Russo E, et al. Vaporized D-limonene selectively mitigates the acute anxiogenic effects of Δ9-tetrahydrocannabinol in healthy adults who intermittently use cannabis. Drug Alcohol Depend. 2024;257:111267. https://pubmed.ncbi.nlm.nih.gov/38498958/

5. Christensen C, Rose M, Cornett C, Allesø M. Decoding the Postulated Entourage Effect of Medicinal Cannabis: What It Is and What It Isn’t. Biomedicines. 2023;11(8):2323. https://pmc.ncbi.nlm.nih.gov/articles/PMC10452568/