There is no single answer to how long medical cannabis takes to work. Medical cannabis onset time can depend on how the medication is consumed, as well as you as an individual. Everyone’s body is different.
Since 2018, medical cannabis has been legally available in the UK when prescribed by a specialist doctor through licensed clinics like Alternaleaf. You can find out if you’re eligible for a medical cannabis prescription by completing the quick eligibility checker on our website.
Please note: Cannabis-based medicines are prescription-only medicines. They may not be suitable for everyone, and eligibility is determined by independent clinical assessment. Treatment is not first-line and outcomes vary; benefits are not guaranteed, and side effects and risks exist.
Below we’ll be exploring these different methods of consumption, and how long each may take to result in effects.
What Factors Affect How Quickly Medical Cannabis Takes to Work?
Several factors can influence how quickly medical cannabis takes to work, and this can vary from person to person.
- The method of consumption (from oral to inhalation) can affect how quickly compounds are absorbed and how long they remain in the body
- Individual metabolism
- Body composition
- The specific product prescribed, including its THC and CBD composition
- Whether or not the medication is taken with food
- Prior experience with cannabinoids - if you’re new to medical cannabis, we always recommend you start low and go slow.
The above can all affect how the body responds, absorbs and processes cannabinoids. Now let's dive into medical cannabis effects timeline depending on method of consumption.
How Long Does Inhaled Medical Cannabis Take to Work?
This method of consumption is associated with a rapid onset of effects, typically within minutes, which some patients may find preferable when quicker onset is desired. Effects usually last between 1 and 3 hours. A dry herb vaporiser may be needed where inhalation is prescribed. These should be supplied though a licensed pharmacy or medical cannabis clinic in the UK.
How Long Does Medical Cannabis Oil Take to Work?
Placing cannabis oil or tincture under the tongue usually starts working within 15 to 30 minutes, and may be associated with longer-lasting effects compared with inhalation.
Swallowed oils or capsules can take longer as they have to pass through the digestive system - onset of effects is usually between 1 to 2 hours. But again effects may last for longer compared with other routes of administration.
How Long Does Topical Medical Cannabis Take to Work?
Applying cannabis-infused products directly to the skin is sometimes discussed in the context of localised areas of discomfort, although evidence and licensed use in the UK remain limited.
Onset is typically 15–45 minutes. Please note, you should only ever apply a medication topically if it has been advised by your doctor. The majority of medical cannabis products available for prescription are for consumption via inhalation or sublingually only.
How Long Do the Effects of Medical Cannabis Last?
So, how long does cannabis stay effective? Again, this can vary depending on method of consumption, and each individual. But here’s a rough guide:
Inhaled: effects are typically reported to last between 1 and 3 hours
Sublingual: effects are typically reported to last between 4 and 6 hours
Oral: effects are typically reported to last between 6 and 8 hours, sometimes longer
It’s important to follow the guidance and advice of your clinician. They will prescribe based on your individual needs and condition. If you feel effects aren’t lasting long enough or taking effect quick enough, speak to your clinician about this, rather than re-dosing yourself. They may then switch up your method of consumption, strain, or even offer other guidance about how you should consume your medication.
What Patients Should Know When Starting Treatment
As we mentioned above, we always recommend you start low and go slow. This means starting at the lowest prescribed dose, especially if you’re completely new to medical cannabis. Your clinician will also guide you through your treatment during your first few appointments, and at Alternaleaf, we’re always on hand to answer any questions and help you throughout your entire medical cannabis journey.
As we covered above, effects may not be immediate, so it’s important to avoid re-dosing too quickly and to allow time for the medication to take effect. As we said above, if you feel effects aren’t lasting long enough or taking effect quick enough, speak to your clinician about this.
Keeping a simple symptom journal can help track your responses and and may be something you want to discuss with your clinician if you find a certain strain or method of consumption isn’t working for you. Gradual dose adjustment (titration) over several days or weeks is a normal part of finding the most appropriate dose for you and your needs, under medical supervision of course.
If you’re looking to explore medical cannabis in the UK, a good place to start is by completing our 30 second eligibility checker.
FAQs
Can response time vary between patients?
Yes, response time can vary between patients due to differences in factors such as metabolism, body composition, and how the medication is consumed.
Should I change my dose if effects feel delayed?
No, patients should not change their dose if effects feel delayed and should follow their clinician’s guidance, allowing time for the medication to work as prescribed. Speak to your clinician if something isn’t working for you.
Does eating before taking medical cannabis affect how quickly it works?
Yes, eating before taking medical cannabis can affect how quickly it works, as food may change how the body absorbs cannabinoids depending on the product and method of consumption.
Summary
If you’re considering medical cannabis, the best thing to do is seek the help of a licensed medical cannabis clinic like Alternaleaf. Find out if you’re eligible by heading to our website and completing our 30 second eligibility checker.