How Long Does CBD Stay in Your System?

This is a science-based examination of the half-life of CBD.

Today you’re going to learn:

• How long CBD stays in your system based on various consumption methods;
• Why it matters how long CBD stays in your system, and;
• What you can do to increase or decrease the half-life of CBD.

For example:

Did you know the half-life of CBD can range anywhere between 1 hour and 5 days, based on consumption method and consumption frequency and duration?

Let’s get started.

Table of contents:

What's the Half-Life of CBD

Half-Life of CBD After Oral Consumption

Half-Life of CBD After Sublingual/Oromucosal Consumption

Half-Life of CBD After Smoking or Vaping

Why CBD Half-Life Matters

How to Increase or Decrease the Half-Life of CBD

Conclusion

What’s the Half-Life of CBD?

The half-life of CBD refers to how long CBD stays in your system, expressed in the time required for the consumed CBD to reduce to half of its original value.

The half-life of CBD is highly dependent on three things:

• The consumption method;
• The consumption frequency, and;
• The dose of CBD.

Let me explain.

The consumption method refers to how you consume your CBD. For example, CBD flower is smoked or vaped, while tinctures are taken sublingually and orally.

When you smoke or vape CBD, it gets absorbed through the air sacs (alveoli) and goes directly into your bloodstream. In this process of smoking/vaping, CBD is absorbed much faster than when it has to go through the gastrointestinal tract, like with oral consumption.

However, here’s the other side of fast-acting consumption methods:

CBD generally also leaves your system faster when taken through methods that lead to faster effects.

For the average consumer, there are three practical ways to consume CBD:

• Oral consumption;
• Sublingual or oromucosal consumption, and;
• Smoking or vaping.

Each of these methods will result in a different length as to how long CBD stays in your system.

But how often you consume CBD also has a large impact on the half-life of CBD.

The more frequently you consume CBD, and the longer the period that you consume CBD, the longer a single dose of CBD will stay in your system.

The half-life of CBD for someone that never uses CBD is significantly lower for someone that uses CBD regularly. The difference can be hours vs days.

The dose size also has a large influence on the half-life of CBD. A dose of 500mg will stay longer in your system than 50mg.

Now:

Let’s dive a bit deeper into the consumption methods first.

Half-Life of CBD After Oral Consumption

Oral consumption means literally swallowing the CBD and letting it go through your gastrointestinal tract.

For most people, this type of CBD will come in the form of gummies or oil/tincture.

One 2004 study found that the half-life of CBD after oral consumption, after a single dose of CBD for someone who never uses CBD is 1.09 hours for a dose of 10mg and 1.97 hours for a dose of 20mg (1). As you can see, with the doubling of the dose, the half-life also almost doubles.

A different 2017 study found that the half-life of CBD was between 2.95 hours and 3.21 hours, after consumption of 10 mg oral lipid capsules (2).

These studies came to significantly different half-life measurements. On closer look, although the study refers to the consumption method as ‘oral’, the first study didn’t study a pure oral consumption method. The consumption method in the first study was partially sublingual, which can explain the lower half-life.

Now:

When you start increasing the number of days you use CBD, the half-life also increases significantly.

One 1991 study found that daily oral use of CBD for 6 weeks, results in a CBD half-life of 2-5 days at the end of these 6 weeks (3).

So, after 6 weeks of using CBD, it can still be found in your body 5 days after you stop using it in some cases.

Half-Life of CBD After Sublingual/Oromucosal Consumption

Sublingual and oromucosal consumption refers to absorbing CBD through the mucous membranes in your mouth, mainly under your tongue and in your cheeks.

For most people, this type of CBD will come in the form of an oil or tincture.

With this method, you partially bypass the gastrointestinal tract and avoid your stomach and liver breaking down a large portion of the CBD. This breaking down of CBD in the gastrointestinal tract is also called the first-pass effect.

One 2017 study found that the half-life of 10mg CBD taken as an oromucosal spray was 2.9 hours on average (4). The same study found that the same oromucosal spray, but with a dose of 100mg CBD had a half-life of 3.6 hours on average.

Here we see again:

The higher the dose the longer CBD stays in your system.

We can also see different studies find a different half-life of CBD, with the same consumption method.

For example:

The first study in the “oral consumption” paragraph above, the study that referred to “oral consumption” as a combination of sublingual consumption and swallowing (1) found CBD to have a half-life of 1 to 2 hours. This is less than the 2.9 hours found in this last study.

How is this possible?

One explanation is that both studies didn’t account for how full the stomachs of the study participants were. Taking CBD on a full stomach leads to significantly higher absorption rates, which in turn may lead to a longer half-life.

Also Read: Most Effective Form of CBD

Half-Life of CBD After Smoking or Vaping

Although smoking or vaping CBD has almost instant effects, interestingly, at least one study found that CBD half-life is significantly longer when it’s smoked or vaped compared to other methods of consumption.

This 1986 study estimated that the half-life after smoking 20mg CBD, is approximately 31 hours (5).

Based on user experiences and anecdotal reports it seems highly counterintuitive that smoking or vaping CBD will lead to a longer half-life than oral or sublingual consumption.

Here’s why:

CBD users consistently report that the effects of oral and sublingual forms of CBD last much longer than smoked or vaped CBD.

Reviewing hundreds of CBD products in the past years, we have definitely experienced the same at Herbonaut.

What could explain these results?

The study participants were regular marijuana users. Marijuana contains CBD, albeit in small amounts.

This could explain why the half-life of smoked CBD was so much higher in this study compared to the earlier mentioned studies that looked at the half-life of CBD after oral and sublingual/oromucosal consumption.

We saw that while a single dose of CBD in the form of an oral solution or sublingual/oromucosal spray has a half-life of 1 to 3 hours, 6 weeks of daily oral consumption of CBD can increase CBD’s half-life to between 2 and 5 days.

It’s likely that chronically smoked/vaped CBD has a significantly longer half-life than a 1-time dose. And the participants in this study very likely inhaled CBD regularly with their marijuana use.

In this day and age, we don't ever recommend smoking CBD. Instead, use a dry herb vaporizer to vape CBD flower.

Why CBD Half-Life Matters

You might be wondering:

How do all these different half-life measurements apply to an average CBD user?

Well, if you’re using CBD medically or for its direct noticeable effects, you would want CBD to stay in your system as long as possible.

The longer the CBD stays in your system, the longer you’ll experience its medical and beneficial effects.

Some of the most popular reasons people use CBD include:

• Its anxiety-reducing effects;
• Its pain-reducing effects, and;
• Its sleep-improving effects.

If you want to keep CBD in your system for as long as possible, based on these studies, there are a few things you can do, which we’ll talk about next.

How to Increase or Decrease the Half-Life of CBD

You’ve learned that CBD’s half-life is dependent on the following three factors:

• The consumption method;
• The consumption frequency, and;
• The dose of CBD.

Based on the current evidence, it’s likely that orally consumed CBD has a longer half-life than sublingually/oromucosally consumed CBD or vaped/smoked CBD.

But what matters most for CBD half-life is consumption frequency, consumption duration, and dose.

We can say that the more often you consume CBD, the longer it will stay in your system with each consecutive dose.

We can also say, the higher your dose, the longer CBD will stay in your system.

Now:

With regards to this last point, it’s important to realize that when it comes to oral and sublingual/oromucosal consumption, there are ways to increase the bioavailability of CBD up to three times.

When you use these tips, you can increase the concentration of CBD in your blood, without upping the dose. By increasing the concentration of CBD in your blood, you’ll also increase its half-life.

What are some ways to increase the bioavailability of CBD up to three times?

The first way is related to the solubility of CBD. CBD is fat-soluble. Fat-soluble compounds like CBD don’t get absorbed very well in the gastrointestinal tract. But by consuming your CBD with dietary fats like olive oil, you can increase its bioavailability up to three times (6).

How many fats should you then exactly take?

This hasn’t been researched to such an exact extent.

However other studies have found that when you take CBD in a fed-state, meaning on a full stomach, you can increase its bioavailability up to 3-times as well (7).

If you simply take CBD after a meal that contains at least some fats, you’ll be fine.

Related: How to Use CBD Products

Summary:

Orally or sublingually/oromucosally consumed CBD should be taken after a meal that has at least some fat content.

Although I don’t see any reason to want a short half-life when using CBD…

If you infrequently vape small doses of CBD, it seems likely that you’ll experience the shortest half-life.

Conclusion

You’ve learned that CBD can stay in your system anywhere ranging from 1 hour to 5 days.

How long CBD exactly stays in your system is highly dependent on the following three factors:

• • The consumption method;

• The consumption frequency, and;
• The dose of CBD.

If you want CBD to stay in your system as long as possible, the most important tip is:

Take it frequently and consistently. The consumption method is less important.

What's Next…

Go  to our CBD Hub to learn more about CBD-related topics.

Scientific References:

1. Guy, G. W., & Flint, M. E. (2004). A Single Centre, Placebo-Controlled, Four Period, Crossover, Tolerability Study Assessing, Pharmacodynamic Effects, Pharmacokinetic Characteristics and Cognitive Profiles of a Single Dose of Three Formulations of Cannabis Based Medicine Extracts (CBMEs) (GWPD9901), Plus a Two Period Tolerability Study Comparing Pharmacodynamic Effects and Pharmacokinetic Characteristics of a Single Dose of a Cannabis Based Medicine Extract Given via Two Administration Routes (GWPD9901 EXT). Journal of Cannabis Therapeutics, 3(3), 35–77. https://doi.org/10.1300/j175v03n03_03
2. Atsmon, J., Cherniakov, I., Izgelov, D., Hoffman, A., Domb, A. J., Deutsch, L., . . . Sacks, H. (2018). PTL401, a New Formulation Based on Pro-Nano Dispersion Technology, Improves Oral Cannabinoids Bioavailability in Healthy Volunteers. Journal of Pharmaceutical Sciences, 107(5), 1423–1429. https://doi.org/10.1016/j.xphs.2017.12.020
3. Consroe, P., Kennedy, K., & Schram, K. (1991). Assay of plasma cannabidiol by capillary gas chromatography/ion trap mass spectroscopy following high-dose repeated daily oral administration in humans. Pharmacology Biochemistry and Behavior, 40(3), 517–522. https://doi.org/10.1016/0091-3057(91)90357-8
4. Atsmon, J., Heffetz, D., Deutsch, L., Deutsch, F., & Sacks, H. (2017). Single-Dose Pharmacokinetics of Oral Cannabidiol Following Administration of PTL101: A New Formulation Based on Gelatin Matrix Pellets Technology. Clinical Pharmacology in Drug Development, 7(7), 751–758. https://doi.org/10.1002/cpdd.408
5. Ohlsson, A., Lindgren, J. E., Andersson, S., Agurell, S., Gillespie, H., & Hollister, L. E. (1986). Single-dose kinetics of deuterium-labelled cannabidiol in man after smoking and intravenous administration. Biological Mass Spectrometry, 13(2), 77–83. https://doi.org/10.1002/bms.1200130206
6. Zgair, A., Wong, J. C., Lee, J. B., Mistry, J., Sivak, O., Wasan, K. M., Hennig, I. M., Barrett, D. A., Constantinescu, C. S., Fischer, P. M., & Gershkovich, P. (2016). Dietary fats and pharmaceutical lipid excipients increase systemic exposure to orally administered cannabis and cannabis-based medicines. American journal of translational research, 8(8), 3448–3459. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5009397/
7. Stott, C. G., White, L., Wright, S., Wilbraham, D., & Guy, G. W. (2012). A phase I study to assess the effect of food on the single dose bioavailability of the THC/CBD oromucosal spray. European Journal of Clinical Pharmacology, 69(4), 825–834. https://doi.org/10.1007/s00228-012-1393-4