Medical cannabis can be prescribed in several different formats, including cannabis oils, pastilles, dried cannabis flower for vaporisation, medical cannabis vape cartridges, and – in some cases – suppositories or pessaries.
Each format delivers cannabinoids to the body in slightly different ways. Some forms may take longer to take effect but last longer, while others may work more quickly. Certain formats may also be better tolerated or more suitable for some patients than others.
Medical cannabis is often discussed in terms of its cannabinoid and terpene profile, the natural compounds responsible for its effects. However, the way a patient takes their medicine can also influence how quickly the effects begin and how long they last.
In this guide, we explain the key medical cannabis formulations and how they are typically used. This can help patients understand the formats that may be prescribed and prepare for discussions with a specialist clinician if treatment is considered appropriate.
At a Glance
- Medical cannabis may be prescribed in several formats, including dried cannabis flower for vaporisation, cannabis oil, pastilles, medical cannabis vape cartridges and, in some cases, suppositories or pessaries. The format prescribed depends on the patient’s needs and lifestyle.
- Pastilles are oral medical cannabis products that are chewed and swallowed. Unlike many over-the-counter cannabis edibles sold as food supplements, medical cannabis pastilles are regulated medicines that can only be prescribed by specialist clinicians.
- Suppositories and pessaries are a newer format that may suit patients with symptoms affecting the pelvis, rectum, reproductive organs or digestive system. They may also be considered for patients who cannot easily take medicines by mouth.
- The most suitable way to take medical cannabis is decided during a consultation with a specialist clinician, based on the patient’s condition, treatment needs and personal preference.
What Medical Cannabis Products are Available in the UK?
Specialist clinicians in the UK may prescribe medical cannabis in a range of different formats. The most common include cannabis oils, oral formulations such as pastilles or capsules, medical vape and dried cannabis flower for vaporisation.
In some circumstances, medical cannabis may also be prescribed as a suppository (inserted into the rectum) or a pessary (inserted into the vagina).
The prescribing clinician recommends the most suitable format for each person, based on their clinical assessment and treatment needs, and advises on how to use it appropriately.
Medical Cannabis Vaporisers
Some medical cannabis formulations are designed to be inhaled using a vaporiser. Vaporising works by heating cannabis to a temperature that releases cannabinoids and terpenes as a vapour without burning the plant material.
Unlike smoking, vaporisation does not involve combustion. This means fewer harmful toxins and by-products are produced compared with burning cannabis.
Dried cannabis flower
When dried cannabis flower is prescribed in the UK, it is intended to be used with a dry-herb vaporiser rather than smoked due to the harmful effects associated with smoking.
There are currently two medically approved vaporisers designed for use with prescribed cannabis flower in the UK: the Volcano Medic and Mighty+ Medic.
For more information about this method of administration, see our guide explaining why vaporising cannabis is considered a safer alternative to smoking.
Medical cannabis vape cartridges
Some medical cannabis formulations are provided as cannabis extracts in pre-filled cartridges that are used with a compatible vaporiser pen. These devices heat the extract to produce a vapour that can be inhaled.
Because the extract is already processed, vape pens do not require grinding or preparation of dried cannabis flower before use.
Patients should always follow the instructions provided by their prescribing clinician when using any vaporised medical cannabis product.
Edibles
Some people refer to cannabis products taken by mouth as “edibles”. In medical cannabis prescribing, these are usually in the form of pastilles.
Medical cannabis pastilles are chewable formulations containing a measured dose of cannabinoids such as cannabidiol (CBD) or tetrahydrocannabinol (THC).
Unlike recreational cannabis edibles such as gummies or baked goods, medical cannabis pastilles are manufactured to pharmaceutical standards and can only be prescribed by licensed specialist clinicians.
Medical Cannabis Oil
Medical cannabis oil contains cannabis extracts combined with a carrier oil. It is usually taken using a dropper placed under the tongue, allowing cannabinoids to be absorbed through the lining of the mouth.
Some of the oil may also be swallowed, meaning cannabinoids can be absorbed through the digestive system. This can result in a slower onset of effects compared with inhaled medical cannabis.
Cannabis oils allow clinicians to prescribe precise doses that patients can measure using the dropper.
To find out more, see our guide answering common questions about medical cannabis oil.
Medical Cannabis Suppositories and Pessaries
A clinician may prescribe medical cannabis as a suppository or pessary when this is the most suitable option. These terms describe the route of administration rather than different products: a suppository is inserted into the rectum, and a pessary is inserted into the vagina.
Your clinician will explain how to use your medicine. Detailed instructions are also included on your dispensing label and in any patient information supplied with your medicine.
What is the Difference Between Different Methods of Taking Medical Cannabis?
Different medical cannabis formats vary in how they are administered and how quickly their effects may begin. When prescribing treatment, clinicians consider these factors alongside a patient’s symptoms, treatment goals, and lifestyle.
The most appropriate formulation will depend on an individual clinical assessment and should always be discussed with a specialist clinician.
The table below outlines some of the key characteristics of commonly prescribed medical cannabis formats.
Cannabis Formats and Usage
| Format | How it is taken | Typical onset | Typical duration | Good to know |
| Dried flower (vaporised) | Inhaled as a vapour using a dry-herb vaporiser | Faster (minutes) | Shorter | Not for smoking; used with an approved dry-herb vaporiser |
| Vape cartridge | Inhaled as a vapour using a compatible vape pen | Faster (minutes) | Shorter | Pre-filled extract; no grinding or preparation needed |
| Oil | Drops under the tongue; some is swallowed | Slower (up to ~1–2 hours if swallowed) | Longer | Precise dosing using the dropper |
| Pastilles | Chewed and swallowed | Slower | Longer | Measured dose; a regulated medicine, not a food supplement |
| Capsules | Swallowed whole | Slower | Longer | Measured dose taken by mouth |
| Suppositories / pessaries | Inserted into the rectum (suppository) or vagina (pessary) | Varies | Varies | May suit those unable to take oral medicines, or with pelvic/local symptoms |
Can you Smoke Medical Cannabis?
In the UK, medical cannabis flower is not prescribed to be smoked. Instead, clinicians advise patients to use a dry-herb vaporiser.
This is because burning cannabis produces harmful toxins and irritants that can affect lung health. Smoking can also change the balance of cannabinoids and terpenes released from the flower, which may affect how the medicine works. Vaporising heats the cannabis without burning it, releasing these compounds as a vapour instead of smoke.
Patients prescribed medical cannabis flower are advised to follow their clinician’s instructions and use a dry-herb vaporiser when taking their medication.
How Do I Find the Right Method of Taking Medical Cannabis for Me?
The most appropriate way to take medical cannabis is determined by a specialist clinician based on your treatment needs and lifestyle. During your initial consultation, the clinician will assess your condition and discuss whether medical cannabis may be an appropriate treatment option. As part of this conversation, they may also discuss different formats of medical cannabis – such as oils, pastilles, vaporised cannabis flower, or medical cannabis vape cartridges.
After the consultation, your case is reviewed by a multidisciplinary team (MDT). If medical cannabis treatment is approved, the prescription discussed during your consultation can then be issued.
When considering which format may be most appropriate, clinicians may take several factors into account, including:
- Your condition and symptoms: Some formulations may be more suitable depending on how quickly effects are needed or how long they should last.
- Your daily routine: Certain formats may be easier to use at particular times of day or in specific situations.
- Previous experience with medication: Patients may already be familiar with certain ways of taking medication.
- Personal preference: Patients may feel more comfortable with certain administration methods than others.
Medical cannabis treatment is reviewed regularly. During follow-up appointments, patients can discuss how their treatment is working and whether any adjustments, including changes to the formulation, may be appropriate.
What are the Side Effects of Different Types of Medical Cannabis Products?
Most medical cannabis formulations share similar potential side effects because they contain the same active compounds. The most commonly reported side effects of medical cannabis include dry mouth, dizziness, sleepiness, fatigue and headaches, although not everyone will experience these and they can vary from person to person.
However, the way medical cannabis is taken can influence how some side effects are experienced.
Vaporised medical cannabis
Some patients prescribed dried flower for vaporising may experience throat irritation or coughing, particularly if they are not used to inhaling vapour. In some cases, vaporising may also cause temporary lung irritation. Clinicians will consider a patient’s respiratory health before recommending dried cannabis flower.
Oral formulations such as oils or pastilles
Oils and pastilles take longer to produce noticeable effects because cannabinoids are absorbed through the mouth and digestive system. This delayed onset means patients may not feel the effects immediately.
For this reason, it is important that patients follow their prescribed dosing instructions and avoid taking additional doses too soon. If a patient feels their medication is not working as expected, they should discuss this with their clinician rather than adjusting the dose themselves.
Suppositories and pessaries
Because suppositories and pessaries are absorbed through the mucosal lining rather than swallowed or inhaled, the medicine enters the body differently. This can affect how much reaches the bloodstream and the side effects some people experience. As with all medical cannabis products, discuss any concerns about side effects with your prescribing clinician.
To find out more, read our guide covering the side effects of medical cannabis.
Conclusion
Medical cannabis may be prescribed in a number of different formats, including oils, pastilles, dried cannabis flower for vaporisation and medical cannabis vape cartridges. If you’re unsure which option may be right for you, this will be discussed with a specialist clinician during your consultation. If treatment is approved, patients continue to be supported throughout their care and can discuss any questions or concerns about their medication during follow-up appointments.
Interested in finding out if you may be eligible? Curaleaf Clinic offers a free eligibility assessment to help determine whether you may be suitable for a consultation.
You can also read our guide on how eligible patients receive their medical cannabis prescription and what happens once treatment has been approved.
References
[1] Barrus, D. G., Capogrossi, K. L., Cates, S. C., Gourdet, C. K., Peiper, N. C., Novak, S. P., Lefever, T. W., & Wiley, J. L. (2016). Tasty THC: Promises and Challenges of Cannabis Edibles. Methods report (RTI Press), 2016, 10.3768/rtipress.2016.op.0035.1611. https://doi.org/10.3768/rtipress.2016.op.0035.1611
