How long does CBD oil take to work?

by Tom Russell July 05, 2022

How long does CBD oil take to work

Before taking any new supplement, it’s useful to know when it will start to work and how long it will stay in your system. For CBD oils, this will be affected by several factors including how you choose to take it, the type of extract it contains and your body composition.

Let’s take a closer look at how CBD behaves in your body so you can gain a clear understanding of what to expect when you take it.

Important terms

Bioavailability – The amount of CBD, from each serving, that reaches your bloodstream intact.

Half-life – The time it takes for the concentration of CBD in your body to reduce by half.

Sublingual – This is the most efficient method to take CBD oil. Drops of the oil are placed under your tongue and allowed to absorb into your ‘sublingual’ blood vessels.

Full-spectrum – Full-spectrum CBD contains a complete range of cannabinoids found in the hemp plant, including THC.

Broad-spectrum – This refers to a CBD extract that includes all of the cannabinoids from the hemp plant except for THC.

Isolate – An isolate is a name given to a pure cannabinoid such as CBD. Products that contain CBD isolate won’t contain any other cannabinoids.

Fast facts

  • When swallowed, CBD oil can take effect in as little as 30 minutes or up to 2 hours.
  • When placed under the tongue, CBD oil will start to work in 15 to 25 minutes.
  • How long it takes CBD oil to work is affected by the amount you take, the type of extract, how you take it and your body composition.
  • The half-life of CBD oil taken orally is about 1 to 2 days.
  • The half-life of CBD oil taken under the tongue is 6 hours.

Factors that affect how CBD behaves in your body

Human body

CBD affects each person slightly differently; these are the main factors that influence how it behaves when you take it:

  1. How you consume it – The route that CBD takes into your body influences its bioavailability and dictates how much will be broken down before it reaches your bloodstream. Inhaling CBD vapour or letting oil absorb under your tongue allows between 35% and 56% to survive for use in your body, whereas swallowing it can leave as little as 4%.
  2. The serving size – The larger the amount of CBD you take the quicker it will reach a high enough blood concentration for the effects to be noticeable. Also, the higher the concentration of CBD the longer it will last in your bloodstream.
  3. How often you take CBD – If you take CBD several times a day it can start to build up in your body producing faster, longer-lasting results.
  4. The type of extract – The entourage effect theory suggests that taking several cannabinoids together can affect how they interact with your body. This could include how quickly they start to work and how long they stay in your system. CBD products that contain a full-spectrum or broad-spectrum extract will deliver the entourage effect but those made with CBD isolate won’t.
  5. Your body composition – Your metabolism, body mass and the ratio of body tissue types will change how CBD affects you. It’s also likely to influence how quickly you’ll notice any effects and how long it stays in your system.

How long does CBD oil take to work?

15-25 minutes

CBD oil can either be used sublingually and placed under the tongue or swallowed. If you choose to take it under the tongue it will take from 15 minutes to 25 minutes to work. Should you decide to swallow it instead, you can expect to notice the first effects in between 30 minutes and 2 hours.

Placing drops of CBD oil under your tongue offers better bioavailability and quicker effects. When the CBD oil rests on the soft tissue at the base of your mouth it’s quickly transported across the narrow membranes into your blood vessels.

However, if you swallow it, the molecules must pass through your digestive system and cross through your gut wall before reaching your blood vessels. This is a much longer journey and more cannabinoids will be broken down on the way.

Will CBD oil work the first time I take it?

When you take CBD oil for the first time, it’s wise to start with a small amount. As a result, you may not notice any effects the first few times. If you consume regularly, you will begin to see results as the CBD builds up in your system or if you slowly increase the daily serving size.

How long does it take other CBD products to work?

Different CBD products are used in a variety of ways which affects how long it takes them to work:

CBD capsules, gummies and ediblesThese are all likely to be swallowed so will take between 30 minutes and 2 hours to work.

CBD e-liquidsE-liquids are vaporised and inhaled into the lungs. This means that they quickly cross into your blood vessels. Consequently, you will notice an effect between 10 and 20 minutes after your first inhalation.

CBD balmsThese are applied directly to the area where the effects are needed. The CBD stays in the affected area so it will start to work relatively quickly, in 25 to 45 minutes.

How long do the effects of CBD oil last?


How long it takes to work

How long the effects last


30 minutes – 2 hours

4 – 6 hours

Absorbed under your tongue

15 – 25 minutes

3 – 5 hours


10 – 20 minutes

2 – 4 hours

Applied topically

25 – 45 minutes

3 – 5 hours

Most CBD products create effects that can be felt for between 2 to 6 hours. Inhaling e-liquid vapour or placing CBD oil under your tongue are methods that produce quick results, but their impact will also be shorter-lasting.

Products that take longer to work, like CBD oil and capsules that have been swallowed, will stay effective for longer.

How long does CBD stay in your system?

green hemp clock

To work out how long any substance remains in your body scientists calculate its half-life. This is the time it takes for half of the original measure to be broken down in certain conditions. For example, if you consumed 20mg of CBD, its half-life would be the time it takes for only 10mg to remain in your system.

In a 2014 report, professors from Drake University in Des Moines and the University of Wisconsin concluded that the half-life of orally ingested CBD was between 1 to 2 days. Later, in 2020, a study was published in the British Journal of Clinical Pharmacology that found that the CBD placed under the tongue had a half-life of only 6 hours.

This indicates that however you take CBD, two days later less than half of it will remain. Another two days after that, it will be less than a quarter of the original serving. At this rate, it will likely be undetectable within 1 to 3 weeks, depending on how much you took and the other factors previously mentioned.

How long is CBD detectable in urine?

The metabolites of CBD are likely to be detectable in urine for up to 3 weeks after you last took it. However, CBD is legal in the UK and is not typically tested for in urine by police or employers.


Depending on how you use it, CBD oil can begin to work at any time from 15 minutes to 2 hours after you take it. The effects can last for up to 6 hours and three weeks later it will likely be undetectable in your system.

Because these timings are slightly different for everyone, we recommend starting with 10mg of CBD oil placed under your tongue two times a day. This will let you control how it affects you and how long any sensations last. After a week you can begin to increase the amount until you get the results you’re looking for.

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Tom Russell
Tom Russell


Tom Russell writes extensively about CBD oil and other groundbreaking food supplements. He and his wife share their home with two daughters and a lifetime’s collection of books.

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