Oil vs Flower vs Vape: Choosing a Medical Cannabis Format

If you have a medical cannabis prescription in New Zealand, one of the first practical questions is what format to use. Oils, dried flower and vaporised flower aren't interchangeable — they differ in how fast they work, how long they last, and how they fit into daily life.

This is a plain-English comparison to help you have a more informed conversation with your prescriber.

Information and education, not advice. 18+. All medical cannabis products discussed here are prescription-only in New Zealand, dispensed through a pharmacy. There are no recreational dispensaries. Format and dose decisions should always be made with your prescriber. This article names no brands or prices as promotion. (Medicinal Cannabis Agency, Ministry of Health.)

First, the basics: everything here needs a prescription

Under the Medicinal Cannabis Scheme (operational since 1 April 2020), products that meet the minimum quality standard are available only on prescription from an NZ-registered doctor and dispensed by a pharmacy. Most products are not funded by Pharmac, so patients generally pay out of pocket. None of these formats can be bought recreationally, grown at home, or imported personally.

With that established, here's how the three main formats compare.

Cannabis oils (oral / oromucosal)

Oils are cannabis extracts in a carrier, taken by mouth — either swallowed or held under the tongue. They come in CBD-dominant, THC-dominant, or balanced formulations.

Onset and duration:

• Onset: slow when swallowed — typically 30 minutes to 2 hours, because the active compounds pass through the digestive system and liver first. Held under the tongue (oromucosal), some absorption can be a bit faster.
• Duration: long — often 6 to 8 hours or more. This makes oils well suited to steady, all-day or overnight symptom control.

Pros:

• Precise, repeatable dosing using a dropper or measured syringe.
• Discreet and smoke-free; no equipment needed.
• Long duration suits chronic, continuous needs (for example, sleep or persistent pain).
• Easy to titrate slowly — "start low, go slow."

Cons:

• Slow onset makes it poor for breakthrough symptoms you need to address quickly.
• The delayed effect can tempt people to re-dose too early; patience matters.
• Effects can feel different from inhaled formats because of how the liver processes swallowed THC.

Dried flower (smoked or, more appropriately, vaporised)

Prescribed dried flower is the cannabis bud itself, supplied with a stated THC (and sometimes CBD) percentage. Smoking is the most harmful way to consume it, and from a health perspective vaporising is strongly preferred (covered below). Many patients are prescribed flower specifically for use in a dry-herb vaporiser.

Onset and duration (inhaled):

• Onset: fast — usually within minutes.
• Duration: shorter — commonly 2 to 4 hours.

Pros:

• Rapid relief, useful for breakthrough symptoms.
• Easy to feel the effect and adjust on the spot.
• The "whole flower" delivers the plant's full range of cannabinoids and terpenes.

Cons:

• Smoking carries real respiratory harm from combustion — vaporising is the safer route (see below).
• Shorter duration means more frequent use across a day.
• Less precise dosing than measured oil; potency varies between cultivars and batches.
• More noticeable (smell, equipment) and less discreet.

Vaporising (dry-herb or extract vaporisers)

Vaporising is a method rather than a separate product: a device heats dried flower (or an extract) to release the active compounds without burning it. Dry-herb vaporisers themselves are legal to own and sell in NZ, but the cannabis used in them must still be prescribed.

Onset and duration:

• Onset: fast — within minutes, similar to smoking.
• Duration: short to moderate — roughly 2 to 4 hours.

Pros:

• Fast onset like smoking, but without combustion — widely considered less harmful to the lungs than smoking.
• More efficient extraction than burning, and no smoke or ash.
• Some control over temperature, which can change the experience.

Cons:

• Requires a device, charging, cleaning and a small learning curve.
• Still an inhaled route, so not zero-risk for the respiratory system.
• Shorter duration than oils; dosing is less precise than measured oil.
• Devices and accessories are an upfront cost.

Side-by-side summary

Format	Onset	Duration	Best suited to	Key drawback
Oil (swallowed/oromucosal)	Slow (30 min–2 hr)	Long (6–8+ hr)	Steady, continuous symptoms; sleep	Too slow for breakthrough symptoms
Dried flower (smoked)	Fast (minutes)	Short (2–4 hr)	Rapid relief	Combustion harms the lungs
Vaporised flower	Fast (minutes)	Short–moderate (2–4 hr)	Rapid relief, lower respiratory harm than smoking	Needs a device; less precise dosing

Onset and duration are general ranges; individual response varies with the product, dose, your physiology and tolerance.

How to think about choosing

There's no single "best" format — the right choice depends on your symptoms, lifestyle and what your prescriber advises. Some general principles patients and clinicians often weigh:

• Continuous, predictable symptoms (e.g. ongoing pain, sleep) often suit oils for their long, steady action.
• Sudden or breakthrough symptoms that need fast relief often suit an inhaled route — and vaporising over smoking for lung health.
• Many patients use a combination — for example, an oil for baseline control plus vaporised flower for breakthrough moments.
• Discretion, smoke-free needs, or workplace considerations push toward oils.
• Driving matters: any THC product can be detected by NZ's roadside oral-fluid testing regardless of format, and detection is not the same as impairment. Read up on the driving rules separately before you make decisions.

FAQ

Which format works fastest? Inhaled formats — vaporised or smoked flower — typically work within minutes. Swallowed oils take 30 minutes to 2 hours.

Which lasts the longest? Oils generally last longest, often 6 to 8 hours or more, because they're processed through the digestive system.

Is vaping safer than smoking? Vaporising avoids combustion, which is the main source of respiratory harm from smoking, so it is generally considered less harmful. It is still an inhaled route and not risk-free.

Can I just buy these formats over the counter? No. All of these are prescription-only in New Zealand and dispensed through a pharmacy. There are no recreational dispensaries, and home growing is illegal even with a prescription.

Can I use more than one format? Many patients do — for example oil for baseline relief and vaporised flower for breakthrough symptoms. Discuss any combination with your prescriber.

Sources

• Medicinal Cannabis Agency (Ministry of Health): https://www.health.govt.nz/regulation-legislation/medicinal-cannabis
• Ministry of Health — medicinal cannabis, information for consumers: https://www.health.govt.nz/regulation-legislation/medicinal-cannabis/information-for-consumers
• Healthify — Cannabis-based products: https://healthify.nz/medicines-a-z/c/cannabis-based-products/
• bpacnz — Medicinal cannabis overview for health practitioners: https://bpac.org.nz/2022/medicinal-cannabis.aspx
• NZ Drug Foundation — harm-reduction tips for medicinal cannabis users: https://drugfoundation.org.nz/news-and-reports/harm-reduction-tips-for-medicinal-cannabis-users

Last reviewed 15 June 2026. All formats are prescription-only in NZ. Discuss format and dose with your prescriber.