Taking prescribed THC for the first time, or after a long break, can bring up a lot of questions. Understandably, you may be wondering how long it takes for THC oil to start working, and what experience you might have when taking it. Here’s your guide to THC oil effects and timings:
How Does THC Oil Work In The Body?
THC stands for tetrahydrocannabinol, a concentrated cannabis plant extract used in medicine for its therapeutic benefits. The two main active substances in the cannabis plant are cannabidiol (CBD) and tetrahydrocannabinol (THC), with the latter being the part that gives people the feeling of being “high”.
Depending on the method of administration, THC enters the bloodstream in different ways. When ingested in edible or capsule form, for example, the bioavailability of THC is 4-12%, as most of it is quickly absorbed by fat tissue. This creates a slower onset than other methods, which isn’t necessarily a negative thing as some people prefer the effects to take place more gradually.
After absorption, THC makes its way to the liver where it is mostly metabolised or eliminated. What’s left over enters the bloodstream. Research suggests that when THC reaches the brain, it can unlock and activate various cannabinoid receptors linked to the body’s endocannabinoid system, which is what produces the therapeutic benefits.
How Long Does THC Oil Take To Work, And How Long Does It Last?
How long THC takes to work will depend on a few things, including the administration method:
Sublingual (Under the Tongue)
This method tends to produce effects fastest, as it’s absorbed straight into blood vessels and avoids the ‘first pass effect’, meaning less THC is lost during absorption.
Sublingual administration involves using a syringe to apply oil under the tongue, and leaving it until it absorbs. Despite its rapid absorption, this method tends to last for less time than others, but this may be preferable for certain conditions and needs.
Benefits may be felt around 20-30 minutes after taking the oil, depending on tolerance. The length of time the effects last will differ for each person, but generally, research suggests sublingual absorption could cause effects to peak after around 2-3 hours.
Oral (Edibles or Capsules)
This method tends to take longer to kick in due to its journey through the digestive tract and being partially eliminated through liver metabolism. However, the effects can last longer, which has benefits depending on your needs. Similar to other medicines, capsule-form THC or edible gummies and other foods or drinks may be easier to ingest.
Depending on dosage and personal tolerance, effects could be experienced within 30-45 minutes, and could last between 3-6 hours, reaching their peak within 3 hours.
Your prescribing doctor will advise on the best method of administration based on your preference and what is likely to have the biggest positive impact on the health condition you are looking to manage or treat. For example, many doctors prefer sublingual methods for pain relief, and it’s thought to be helpful for cardiovascular diseases. Alternatively, studies have found those with multiple sclerosis (MS) or those with chemotherapy-induced nausea could benefit from oral administration.
What Effects Should Be Expected?
With medical direction, the anti-inflammatory and neuroprotective properties of THC oil can be used to treat or manage a number of health conditions, such as:
- Chronic pain
- Insomnia and other sleep issues
- Women’s health issues, such as endometriosis
- Chemotherapy-induced nausea
- Mental health conditions like depression or PTSD
- Gastrointestinal issues like Crohn’s disease
- Neurological conditions like multiple sclerosis (MS)
- Skin issues like acne or eczema
The specific effects and benefits of THC will depend on what health conditions you are struggling with, and several other factors. Some of the most common effects people experience from medical cannabis include:
- Pain relief
- Nausea/sickness relief
- Changes to appetite
- Relaxation and reduced anxiety
- Reduced inflammation
- Improved mood for conditions like depression
- Improved sleep quality
- A feeling of being “high” (if this is a concern for you, speak to your doctor)
While waiting for the effects of THC to take place, try to relax and avoid stress for the best experience. If you become concerned that you’re not feeling any effects from your medical cannabis, speak to your prescribing doctor before attempting to increase your dose on your own. It may be that your prescription is a dosage and method specially chosen for your situation, or is designed to be effective over a long period of time without psychoactive effects. Discuss any concerns with your specialist doctor so they can help.
What Factors Influence THC Oil’s Effects?
A number of factors can influence how THC works within the body, how long it takes to work, and how long it lasts. For example:
- Method of administration: THC oil can be taken in several forms, such as an oil applied under the tongue (sublingual), or in edible or capsule form. Oils are thought to be the strongest option due to their concentration after extraction, which is usually 52-69% THC, but could be up to 95% in some cases.
- Dose: First-time users of medical cannabis and those expected to have a low tolerance might be offered CBD to start, followed by a low dose of THC that can be increased over time. For those with an intermediate or high tolerance, or who have been prescribed medical cannabis previously, a stronger dose may be given.
- Metabolism/weight: An individual’s metabolism and body weight will influence their tolerance, the effects they experience, and the length of time THC takes to work.
- Diet: The food you eat alongside taking THC could affect absorption, with studies finding that taking fatty foods with THC could lead to a significant increase in the exposure to orally administered medical cannabis.
- Strain or formulation: There are also several categories of oil that affect how THC impacts the body; full-spectrum oil maintains all cannabis oils and terpenes from the plant (THC and CBD), broad-spectrum oil maintains some cannabis oils and terpenes from the plant (not THC), and isolate oil maintains only THC from the plant.
- Personal tolerance: When taken on occasion, the plasma half-life of THC is thought to be between 1 and 3 days, whereas in more regular users, the plasma half-life is thought to be between 5 and 13 days. This means occasional users may feel the benefits more quickly, and they could last longer, while more regular users might build up a tolerance. The Start Low, Go Slow principle is often followed for first-time users of medical cannabis, which means they will be initially prescribed a small dose that’s gradually increased over time, under the supervision of a specialist doctor. The aim of this is to maximise its efficacy while minimising any potential side effects.
You can learn more about factors that influence THC’s effects in our guide on how to take THC oil.
Can THC Oil Make You Fail A Drug Test?
The Misuse of Drugs Regulations 2010 categorises many cannabis plant derivatives as illegal, except for products containing less than 1mg of THC. Medical cannabis has also been legal since 2018 provided it is obtained through a prescription from a specialist doctor.
However, if you’re wondering whether this would still show up on a drug test here in the UK, the short answer is yes, depending on the dose you take. According to the Metropolitan Police, you can fail screening for cannabis if you have more than 2 micrograms of THC per millilitre of blood. However, if you are legally prescribed medical cannabis, you have a statutory medical defence under UK law, provided you are not impaired.
It’s also important to be aware of the rules of driving when taking medical cannabis. The UK Road Traffic Act 1988 considers it an “offence to drive while unfit through drink or drugs”. Medical cannabis could impair your judgement and coordination, making it potentially unsafe to be behind the wheel. Even if you don’t feel any psychoactive effects from medical cannabis, this doesn’t mean it can’t impair your judgement when driving, so it’s your responsibility to assess whether you’re safe to drive while taking medical cannabis. If you are ever in doubt, stay on the safe side and get a taxi if you must travel.
What Safety Tips And Best Practices Do I Need To Know?
Overconsumption of cannabis can feel frightening if it happens, but it may be a relief to know that it will soon wear off. Side effects can still occur, so always follow the exact dosage advice given by your prescribing doctor. The potential side effects of THC include:
- Diarrhoea
- Feeling sick
- Behavioural or mood changes
- Dizziness
- Fatigue
- Hallucinations
- Suicidal thoughts
If you experience symptoms such as recurring vomiting, hallucinations, psychosis or suicidal thoughts, seek medical assistance straight away.
Certain groups of people shouldn’t be prescribed medical cannabis in the UK, including:
- Anyone who is pregnant or breastfeeding
- Anyone with certain heart conditions
- Anyone with a history of schizophrenia or psychosis
- Anyone taking certain other medications – always tell your prescribing doctor about other medications you may be taking
- Children and adolescents – keep medical cannabis in a locked storage area where children and pets cannot access it, as consumption of this could lead to them becoming sick or experiencing breathing difficulties that require medical assistance
As well as some of the aforementioned safety tips, it’s best to avoid mixing medical cannabis with alcohol or other medications. Mixing alcohol with other medications can lead to dangerous side effects, and evidence is limited on the impact of drinking while taking medical cannabis. It’s thought that this is best avoided, as alcohol can increase the absorption of THC in the body, which can have negative impacts on your dosage.
These safety tips are precautionary to ensure you get the best experience when taking medical cannabis, but when you start your journey with one of our trusted experts, you will have support whenever you need it. Whether you’re wondering how much medical cannabis to take, how often, or the best administration method for you, we can help.
At Emerald, we work to enhance the lives of people living with challenging health conditions by making it easy for them to access medical cannabis under the care of qualified specialists. We can become a trusted partner in your healthcare journey, offering access to safe, legal medical cannabis of the very best quality and the greatest value. Our team is dedicated to offering unparalleled, long-term support so you can live a more balanced life.