What Are Terpenes? Common Types, Terpenes for Sleep and Safety

What are terpenes?

Terpenes are natural compounds made by plants, partly to attract pollinators and repel pests. They’re found throughout nature and in everyday foods, herbs and essential oils, and they are the main reason one plant smells different from another:

• Lavender gets much of its scent from linalool.
• Orange and lemon peel are rich in limonene.
• Pine needles and rosemary contain pinene.
• Hops, the flowers that flavour beer, contain myrcene and humulene.
• Black pepper and cloves contain beta-caryophyllene.

“Terpenoids” are closely related compounds, often formed when terpenes dry or oxidise; the two words are often used interchangeably. Many terpenes are also used as food flavourings and in perfumes and cosmetics.

Each hemp or cannabis variety has its own terpene profile, which is why they smell different. Even that is less reliable than it sounds: a 2020 study of cannabis plants from 32 seed sources found large differences in terpene profiles between plants sold under the same variety name.

Terpenes vs cannabinoids: do terpenes get you high?

No. Terpenes aren’t intoxicating. The high from cannabis comes from THC, a cannabinoid. Cannabinoids such as CBD, THC and CBG are a separate family of compounds, explained in our guide to cannabinoids and minor cannabinoids.

The two are linked, though. Terpenes and cannabinoids are the two main groups of compounds in cannabis resin, which contains hundreds of them, and terpenes share a chemical precursor with cannabinoids. That shared origin is part of why people wonder whether they work together (see the entourage effect below).

One terpene blurs the line: beta-caryophyllene, found in black pepper, binds to the CB2 receptor, one of the receptors in the body’s endocannabinoid system. Researchers have called it a “dietary cannabinoid” for that reason, even though it is chemically a terpene.

9 common terpenes and what research has found

Most of this research is in cells or animals, often at much higher doses than anyone would get from a food or a CBD product. In the myrcene and limonene mouse study, for example, the effects on sleeping time only appeared at 200mg per kilogram of body weight, injected. That doesn’t show that the small amounts in a few drops of oil have these effects in people.

Terpene charts online often go further, labelling one terpene “for focus” and another “for pain”. Treat those as marketing rather than science.

Terpenes for sleep: what the evidence says

The short answer: no terpene has good evidence as a sleep aid in people. The terpenes most often linked with sleep are myrcene, linalool and terpinolene, and nearly all of that link comes from animal studies.

• Myrcene: in a 2002 mouse study, high injected doses made the animals less active and lengthened drug-induced sleep. A 2021 review of myrcene concluded that it looks promising in animals but that studies in humans are lacking. Its reputation for “couch-lock” comes from cannabis culture rather than trials.
• Linalool: mice that breathed linalool vapour for an hour were less active and slept longer after a sedative drug, without losing coordination. Another mouse study found the calming effect disappeared in mice that couldn’t smell, suggesting the scent itself matters. Human research mostly uses whole lavender oil; we cover it in lavender for sleep.
• Terpinolene: inhaled terpinolene had a sedative effect in mice in a small Japanese study. There are no human trials.
• Hops: hops contain myrcene and humulene and turn up in many bedtime teas and blends. Our best tea for sleep guide ranks those teas by evidence.

One larger human study is often quoted. In a 2025 trial, 125 adults with insomnia took a capsule containing 300mg of CBD plus 1mg each of eight terpenes, including myrcene, linalool and limonene. Time in deep and REM sleep rose slightly on a wrist tracker, but total sleep time didn’t change. The trial was funded by the company behind the formula, 300mg is thirty times the FSA’s 10mg a day figure, and the design can’t tell what the terpenes added on their own. CBD isn’t a treatment for insomnia, and neither are terpenes.

A pleasant scent can still be part of a good wind-down routine, and there’s no harm in enjoying lavender or a hop tea at bedtime. For sleep itself, the basics do the heavy lifting: see our sleep hygiene habits and how to fall asleep fast. The NHS advises seeing a GP if you’ve had trouble sleeping for months, if changing your sleep habits hasn’t helped, or if poor sleep is making it hard to cope day to day.

Terpenes and the entourage effect

The “entourage effect” is the idea that cannabinoids and terpenes work better together than alone. It was popularised by a 2011 review proposing ways terpenes might add to cannabinoids’ effects. The evidence since then points both ways:

• Against: a 2019 lab study found six common cannabis terpenes, including myrcene, limonene and linalool, didn’t change how THC acted on the body’s CB1 or CB2 receptors.
• For: a 2021 study in cells and mice found some terpenes, including humulene, linalool and beta-pinene, produced cannabinoid-like behaviour in mice and added to the effect of a cannabinoid drug.
• In people: in a small 2024 trial of 20 adults, inhaling limonene with a high dose of THC reduced how anxious and paranoid people felt compared with THC alone. Limonene on its own did nothing measurable, and the trial involved THC, which isn’t in broad spectrum CBD.

The idea remains plausible but unproven for everyday CBD oils. Our full guide covers whether the entourage effect is real.

Are terpenes safe?

• In foods and naturally occurring amounts: generally yes. Many terpenes are permitted food flavourings in Great Britain. The FSA’s register lists d-limonene and linalool as authorised, and myrcene, beta-caryophyllene and alpha-pinene as permitted while their safety evaluation is completed.
• Concentrated terpenes: can irritate skin, eyes and airways. Don’t swallow neat terpene oils or essential oils.
• Skin allergy: pure limonene and linalool are weak allergens, but both react with air over time and the oxidised forms can cause contact allergy. In a European study, 2.6% of 2,411 people with dermatitis reacted to oxidised limonene; in a Swedish study, 5 to 7% reacted to oxidised linalool at the higher test strengths. Keep scented oils capped and use them before they go stale.
• Vaping: heating concentrated terpenes can produce irritant breakdown products. Avoid unregulated vape liquids. See can you vape CBD oil?
• Pregnancy, breastfeeding and medication: stick to normal food amounts, avoid concentrated terpene products or essential oils taken by mouth, and ask your midwife, GP or pharmacist if you are unsure.

Terpenes in CBD oils and on lab reports

How many terpenes a CBD oil keeps depends on the type of extract and how it’s processed. Processing can remove some of them, and some brands add terpenes back for flavour. Our guide to how CBD is extracted explains the steps.

See full spectrum vs broad spectrum vs isolate and what is CBD isolate? for more on each.

Botanical vs cannabis-derived terpenes

Added terpenes come from two broad places. Botanical terpenes are taken from other plants, such as limonene from citrus peel or myrcene from hops, or made to food-flavouring standards. Cannabis-derived or hemp-derived terpenes are taken from the hemp plant itself. A single terpene such as limonene is the same molecule either way; what changes is the mix and ratio, which is what shapes the taste. If the source matters to you, ask the brand.

How terpenes appear on a lab report

A CBD lab report (certificate of analysis) always shows the cannabinoids, including THC. Some also include a terpene panel listing each terpene, usually as a percentage or in mg per gram, with the most abundant first. Many don’t test terpenes at all, so a missing panel isn’t a red flag on its own. Our step-by-step guide shows how to read a CBD lab report.

Terpenes are also the main reason oils taste so different. See what CBD oil tastes like and how to make it more pleasant.

Which terpenes are in Evopure oils?

All our CBD oils are broad spectrum, with 0% THC, and are on the FSA’s public list of CBD products linked to novel food applications. Three of them include a terpene blend alongside their botanicals. These are the terpenes listed on each product page:

Oil	Botanicals	Terpenes listed
Sleep CBD Oil	Passion flower	Myrcene (lead), caryophyllene, terpinolene, alpha-pinene
Flow CBD Oil	Ashwagandha, maca	Citral, phellandrene, terpineol, beta-ocimene
Relief CBD Oil	Turmeric, black pepper extract	Limonene, caryophyllene, humulene, alpha-pinene

Each comes in 500mg or 1,000mg, in an MCT oil base, and is vegan, made in the UK and third-party lab tested (reports are available via our lab testing page). The terpenes shape the taste: Sleep is earthy and herbal, and Flow is bright and citrusy, close to honey and lemon. Sleep CBD Oil doesn’t contain linalool or lavender. If you’d rather have CBD with no added botanicals or terpenes, our Broad Spectrum CBD Oil is CBD in MCT oil and nothing else.

The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication.

Our CBD dosage guide has a drops chart for each strength. We don’t recommend our products during pregnancy or breastfeeding. All our products are for adults (18+) only.

Video: what are terpenes and what do they do?

Prefer to watch? Our short explainer covers what terpenes are and why they matter in CBD oils.

See also how is CBD extracted? and hemp vs marijuana.

Related guides

• Why distillation strips out most terpenes.
• Comparing evening oils with terpene blends? See our guide to the best CBD oil for sleep UK, with a 10-point checklist.
• Some brands add terpenes to CBD isolate; the CBD Brothers Pure Black oil lists 18 of them.