How long does CBD stay in your system?
After a single dose, CBD usually leaves the blood within a few days; after weeks of high daily doses, traces can remain for a week or more. Studies measured a half-life of about one day after one injected or inhaled dose and 2–5 days after six weeks of daily oral use. Standard drug tests don't look for CBD at all. They look for THC and its breakdown products.
Key facts
- Half-life, single dose
- 24 hours after injection, 31 hours after inhalation (5 volunteers)
- Half-life, repeated doses
- 2–5 days after six weeks of about 700 mg a day by mouth
- Peak blood level
- About 3–5 hours after a dose by mouth in clinical studies
- Applied to the skin
- Blood CBD was low and often below the measurable limit in a 2026 study of a hemp cosmetic
- Drug tests
- Look for THC or its metabolite THC-COOH, not CBD
- Our oils
- Cosmetics applied to the skin; every batch tested in Switzerland, THC printed on the label to two decimals
How long does CBD stay in your system?
There is no single number, because it depends on how much CBD is used, how often and how it enters the body. The studies give these reference points:
- One dose: in five volunteers, half of an injected dose of CBD was gone from the blood after about 24 hours, and half of an inhaled dose after about 31 hours (Ohlsson et al., 1986).
- Daily use for weeks: in 14 patients who took about 700 mg of CBD a day by mouth for six weeks, the half-life was 2–5 days. One week after they stopped, the average blood level had fallen to 1.5 ng/ml, and after that CBD was "virtually undetectable" (Consroe et al., 1991).
- Twice-daily high doses: in healthy volunteers taking 750 or 1,500 mg twice a day, CBD reached a steady level after about 2 days. The effective half-life was 10–17 hours, and the final elimination phase had a half-life of about 60 hours (Taylor et al., 2018).
A common rule of thumb in pharmacology is that after about five half-lives, roughly 97% of a substance has left the blood. With a half-life of one day, that is about five days; with a half-life of five days, it can be several weeks before the last traces are gone.
What is the half-life of CBD?
The half-life is the time it takes for the amount in the blood to fall by half. For CBD, published values vary widely. A 2018 systematic review of 24 human studies reported half-lives of 1.4–10.9 hours after a mouth spray, 24 hours after injection, 31 hours after smoking and 2–5 days after chronic oral use (Millar et al., 2018).
| Route and dose | Half-life | Study |
|---|---|---|
| Injection, 20 mg, single dose | 24 ± 6 hours | Ohlsson 1986 |
| Smoked, about 19 mg, single dose | 31 ± 4 hours | Ohlsson 1986 |
| Mouth spray | 1.4–10.9 hours | Millar 2018 (review) |
| By mouth, 750–1,500 mg twice a day for 7 days | Effective 10–17 hours; terminal about 60 hours | Taylor 2018 |
| By mouth, about 700 mg a day for 6 weeks | 2–5 days | Consroe 1991 |
| On the skin, single application | Not calculated; blood levels low and often below the measurable limit | Jain 2026 |
Most of these studies were small and used doses far above those in typical consumer products. The review authors point out how few good data exist on CBD's pharmacokinetics, given how widely it is used (Millar et al., 2018).
What affects how long CBD stays in the body?
- How it enters the body. Inhaled CBD reaches its peak blood level faster than oral CBD (Millar et al., 2018). After an oral dose, blood levels peaked after about 3–5 hours in clinical studies (Taylor et al., 2018; Jain et al., 2026). Applied to the skin, very little reached the blood (see below).
- How often it is used. With repeated doses, CBD builds up: twice-daily dosing raised blood levels 1.8–2.6-fold compared with a single dose (Taylor et al., 2018). That is why the half-life after weeks of use is longer.
- How much is used. Higher doses produce higher blood levels, though less than proportionally (Taylor et al., 2018).
- Distribution in the body. CBD spreads widely into body tissues, with a very large apparent volume of distribution (Ohlsson et al., 1986; Taylor et al., 2018).
The body breaks CBD down into metabolites such as 7-hydroxy-CBD and 7-carboxy-CBD (Taylor et al., 2018). In laboratory tests, CBD also blocks several liver enzymes that process medicines (Nasrin et al., 2021). If you take medication, see our guide to CBD and medication.
Does CBD on the skin get into your system?
Very little, according to the one human study that compared the two routes. In 2026, 20 healthy adults used a hemp-extract cosmetic once on the skin and once by mouth. After skin use, CBD in the blood was low and often below the measurable limit, peaking at about 24 hours instead of 3 hours. Total exposure over 24 hours was about 15 times lower than after the oral dose (19 vs 281 h·ng/ml). THC-related compounds were not measurable in the blood after skin use, and urine THC tests were negative (Jain et al., 2026). The study was small, tested one product and was funded by a company in the essential-oils industry.
Our human CBD oils are cosmetics, and their labels direct you to apply them to the skin. See how to use CBD oil.
Will CBD show up on a drug test?
Standard drug tests don't look for CBD. Urine tests look for THC-COOH, a breakdown product of THC, and saliva and blood tests look for THC. In a controlled study, 100 mg of pure CBD, swallowed or vaporised, did not produce a confirmed positive urine test at standard workplace cut-offs (Spindle et al., 2020).
So the question that matters for a drug test is not how long CBD stays in your system, but whether a product contains THC. Our labels print the THC content to two decimals, and the certificate for each batch is on our test results page. If you are tested at work or in sport, choose a THC-free oil and keep the batch report. Our guide CBD, drug tests and driving covers test types, cut-offs and the driving rules in Europe.
How long does CBD take to wear off?
Studies measure blood levels, not how long people feel anything, and effects are not well defined. After an oral dose, blood levels peak within a few hours and then fall, quickly at first and then slowly (Taylor et al., 2018). After skin use, very little CBD reached the blood (Jain et al., 2026).
Can you flush CBD out of your system faster?
No method has been shown to speed it up. Drinking extra water, exercising or "detox" products have not been tested for CBD, and the body clears it at its own rate. Time is the only reliable factor. If a drug test worries you, what counts is avoiding THC, not removing CBD.
From our production
We test every batch in Switzerland, and we have never had a failed test since 2013. Every label shows the THC content to two decimal places, next to the batch number, so you can check the certificate for the exact bottle you have.
— Robin Roy Krigslund-Hansen, co-founder and CEO
Frequently asked questions
How long does CBD stay in your system?
After a single dose, CBD's half-life in studies was about one day, so most of it is gone within a few days. After weeks of high daily oral doses, the half-life was 2–5 days, and traces remained for about a week after stopping.
How long does CBD oil stay in your system?
It depends on the dose, how often it is used and how it is applied. Taken by mouth in studies, CBD peaked in the blood after 3–5 hours and then fell over days. Applied to the skin, blood levels were low and often not measurable.
What is the half-life of CBD?
Published values range from 1.4–10.9 hours after a mouth spray to 24 hours after injection, 31 hours after smoking and 2–5 days after weeks of daily oral use.
Will I fail a drug test if I use CBD?
Not because of CBD: standard tests look for THC and its metabolite THC-COOH, not CBD. A positive result comes from THC in a product, so check the THC value on the label and batch certificate.
How do you flush CBD out of your system fast?
There is no proven way. Water, exercise and detox products have not been shown to clear CBD faster. Time is the only reliable factor.
Does CBD applied to the skin get into the blood?
Only a little. In a 2026 study, CBD in the blood after skin use was low and often below the measurable limit, and about 15 times lower overall than after the same product was taken by mouth.
Related guides
This article summarises published research. It is not medical or legal advice, and no product can guarantee a drug-test result. Formula Swiss CBD oils are sold as cosmetics for use on the skin. They are not food supplements or medicines and are not intended to diagnose, treat, cure or prevent any disease.
Last reviewed:
Sources
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- Consroe P, Kennedy K, Schram K. Assay of plasma cannabidiol by capillary gas chromatography/ion trap mass spectroscopy following high-dose repeated daily oral administration in humans. Pharmacol Biochem Behav 1991;40(3):517–522. doi:10.1016/0091-3057(91)90357-8
- Taylor L, Gidal B, Blakey G, Tayo B, Morrison G. A phase I, randomized, double-blind, placebo-controlled, single ascending dose, multiple dose, and food effect trial of the safety, tolerability and pharmacokinetics of highly purified cannabidiol in healthy subjects. CNS Drugs 2018;32(11):1053–1067. doi:10.1007/s40263-018-0578-5
- Millar SA, Stone NL, Yates AS, O'Sullivan SE. A systematic review on the pharmacokinetics of cannabidiol in humans. Front Pharmacol 2018;9:1365. doi:10.3389/fphar.2018.01365
- Jain M, Hudson R, Tarrell A, et al. Results of an exploratory crossover pharmacokinetic study evaluating a natural hemp extract-based cosmetic product: comparison of topical and oral routes of administration. Pharmaceuticals (Basel) 2026;19(2):231. doi:10.3390/ph19020231
- Spindle TR, Cone EJ, Kuntz D, et al. Urinary pharmacokinetic profile of cannabinoids following administration of vaporized and oral cannabidiol and vaporized CBD-dominant cannabis. J Anal Toxicol 2020;44(2):109–125. doi:10.1093/jat/bkz080
- Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid metabolites as inhibitors of major hepatic CYP450 enzymes, with implications for cannabis-drug interactions. Drug Metab Dispos 2021;49(12):1070–1080. doi:10.1124/dmd.121.000442