Indica

Cannabis Indica is a botanical classification for a subspecies of cannabis plants. It is associated with the Hindu Kush mountain region that spans Afghanistan, Pakistan and northern India, the name indica means ‘India’ in Latin.

The indica cannabis is one of three commonly recognised subspecies of cannabis, which also includes Sativa and Ruderalis.

At a glance: Cannabis indica

Cannabis indica characteristics and origins

The Cannabis indica plant is thought to have originated from the Hindu Kush mountains located across Afghanistan, Pakistan, and northern India. The name indica comes from the Latin word ‘India’ and was named as such by the naturalist Jean-Baptiste Lamarck in 1785.

The region has harsh growing conditions with short growing seasons, cold nights, strong sun at high altitudes, and dry air.

Indica would have traditionally been cultivated for its resin to make concentrates like hash or hashish, which explains why indica types are known for their heavy resin production today, as they would have been selectively grown for this.

The name Indica has a complicated history: while Lamarck described the plant with the indica label, he characterised it as having narrower leaves, whereas today, indica refers to broader-leaf plants that trace back to Afghanistan and Pakistan.

Physically, the modern indica plant is short and often under two metres tall; it has a bushy structure with broad, dark green leaves.

The plant flowers in eight to 11 weeks, and flowers are thick and compact, making them more prone to mould. It's one reason indica-dominant plant types are thought to prefer cooler, less humid environments.

Growers and producers use the indica cultivar as a practical label as well as a descriptive one. They need less space to grow because of their short stature, have a fast growth time, and produce strong yields.

Indica labels are also used for expected effects; however, the label is not reliable, as the plant’s appearance says very little about its chemical makeup.

Do cannabis indica labels predict effects?

The labels of Cannabis indica and other cannabis subspecies are botanical classifications and can tell you the plant variety's name and lineage, but more and more research concludes it is not reliable to describe how a plant will make you feel or what it contains.

A 2021 study in Nature Plants analysed the chemical makeup of almost 300 cannabis samples, including the DNA of 137 of them. The samples labelled indica and sativa were mostly indistinguishable. The labels reflected different aromas, with indica linked to the terpene myrcene.

As world-leading cannabis researcher Dr Ethan Russo has argued, you can't guess a plant's chemistry from its height, branching, or leaves.

That being said, there is anecdotal evidence that indica strains tend to produce more sedative effects and are recommended for nighttime use.

When it comes to what drives the effects of cannabis, researchers and clinicians look at what’s actually inside the plant, using the term chemovar.

Chemovar is short for ‘chemical variety’ and focuses on the chemicals a plant produces such as cannabinoids like THC and CBD, as well as terpenes.

THC and CBD are the most common cannabinoids and have the biggest influence on effects on the body as they interact with the endocannabinoid system.

Terpenes are the compounds that give cannabis its aroma and flavour; they are thought to enhance the effect of cannabinoids. Research is limited, but it is a theory known as the “entourage effect.” Early research in laboratory and animal studies suggests that some terpenes have relaxing or anti-inflammatory properties.

• Myrcene has an earthy and musky aroma, and is the terpene most linked with indica's sedative reputation.

• Beta-caryophyllene is spicy and peppery, and able to bind to CB2 receptors, which help regulate inflammation.

• Humulene is woody and earthy, and studied for its potential anti-inflammatory effects.

• Citronellol has a floral and citrus aroma, and the terpene shows potential in animal research to protect dopamine-producing brain cells in Parkinson’s disease.

This may explain why many patients feel relaxed after taking indica strains. But a plant labelled sativa that is high in myrcene could feel just as calming.

Cannabis indica vs sativa vs ruderalis

Indica is one of three common subspecies of cannabis plants, alongside sativa and ruderalis.

Sativa plants grow taller with narrow leaves and have a long flowering period; they’re more associated with uplifting effects.

Ruderalis is a short, hardy plant that flowers automatically; it is rarely used alone when prescribing medical cannabis.

For a full breakdown on how cannabis types differ, see our guide to indica vs sativa.

Indica-dominant strains in UK medical cannabis

Indica-dominant strains are legal to access through a medical cannabis prescription, and products can be described as indica-dominant, indica, or hybrid.

An indica-dominant product comes from a plant whose lineage is mostly indica; a hybrid has been cross-bred from different cultivars to combine their traits. The majority of cultivars available today are hybrids, so an indica-dominant label is really a description of the plant's lineage rather than its chemical makeup.

Medical cannabis products in the UK are prescribed by specialists and are labelled with their chemovar, the THC and CBD content as a percentage, as well as the main terpenes. This is what clinicians use to choose treatments for patients, as this informs the effects rather than strain labels.

What is indica used for medically?

Indica is historically associated with sedative, relaxing, body-focused effects. 

Indica-dominant cultivars high in the myrcene terpene may be discussed as a possible medical cannabis treatment for those with sleep disorders or chronic pain, as studies have found the terpene may help with pain relief as well as prolong sleep time in mice.

Sedative effects are most likely to come from the product's THC content and terpenes like myrcene, rather than a product labelled indica. Sedative effects are not always welcome for patients and can cause couch-lock.

Clinicians will individually assess each patient and choose a treatment based on cannabinoid content and terpene profile; any side effects should be discussed with your clinician.

Legal status and access in the UK

Medical cannabis has been legal to prescribe by a specialist doctor in the UK since November 2018; recreational cannabis remains illegal as a Class B drug under the Misuse of Drugs Act 1971.

Prescribed cultivars are held to pharmaceutical standards, lab-tested for cannabinoid and terpene content as well as contaminants, and labelled with their THC and CBD percentages.

Frequently asked questions about cannabis indica

What does cannabis indica do to you?

Effects depend on a product's cannabinoid and terpene profile, not its indica label. Indica-dominant cultivars are associated with sedative and relaxing effects.

Is cannabis indica an upper or downer?

Indica is traditionally described as sedative, so it would be described as a ‘downer’, but the reality is that its indica label isn't a reliable predictor of effects.

Is indica-dominant cannabis good for sleep?

Patients report indica-dominant, myrcene-rich cultivars help them sleep, but it is mostly anecdotal. A specialist doctor can assess if medical cannabis is appropriate for sleep problems.

What is cannabis indica mostly used for?

Indica-dominant products are often discussed for sleep problems and chronic pain. Specialists will choose products by their cannabinoid content and terpene profile rather than an indica label.

Is there a 100% pure indica strain?

Very few cultivars are 100% indica, decades of cross-breeding means most modern cultivars are hybrids.

What does indica-dominant mean?

It means the cultivar’s lineage is mostly indica, so the plant tends to be short and bushy; it does not describe effects.

Is cannabis indica legal in the UK?

Cannabis indica is legal in the UK when it is prescribed by a specialist as medical cannabis treatment. 

To find out if you are eligible, try our free medical cannabis eligibility checker, it takes less than 30 seconds to fill in.

Our medical cannabis glossary can also help you learn more about terms you may associate with medical cannabis. 

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