How Does CBD Oil Work in the Body?

Illustration of CBD oil bottle looking at the endocannabinoid system and how it works?
Written by Nina Julia | Last updated: January 19, 2023

This article contains an overview of the most common effects of CBD. We explain how it works with the endocannabinoid system (ECS) and elaborate on various health areas that may benefit from supplementation with CBD oil. After reading this article, you’ll be able to use CBD to optimize your health and pick the right product for your needs in this unregulated market.

Cannabidiol (CBD) is one of the most versatile therapeutic compounds on the planet. It’s a cannabinoid naturally found in cannabis plants — hemp and marijuana.

CBD offers a myriad of health benefits by engaging with the endocannabinoid system (ECS), which regulates homeostasis between the other systems and organs in the body.

Despite the complexity of its effects on the body and brain, CBD doesn’t get you high, unlike THC, the primary psychoactive compound in marijuana plants.

But how does CBD work? What exactly does it do to your health — and is it really as safe as hemp companies are trying to convince you?

Let’s dive deeper into the mechanisms governing CBD’s effects.

What is CBD?

CBD, also known as cannabidiol, is one of 150 cannabinoids naturally synthesized by cannabis plants. It’s is a major cannabinoid whose higher concentrations can be found in hemp — an industrial subvariety of cannabis.

Unlike THC, CBD doesn’t have any intoxicating effects for people (though some people report mild euphoria at high doses) and may even counteract the psychotropic effects of THC.

Raw hemp plants contain cannabidiolic acid (CBDA), which is the acidic precursor of CBD. CBDA turns into CBD after curing or decarboxylation (heating).

Knowing how CBD works in the body will help you understand its medical uses.

But first, let’s shed light on the relationship between CBD and the endocannabinoid system (ECS).

What Is the Endocannabinoid System (ECS)?

The ECS is a complex biological system that was discovered in the 1990s. The discovery sparked the interest in its potential therapeutic uses, but much remains a mystery about how it works and interacts with other systems.

Today, researchers know that the ECS controls several essential processes, including sleep, memory, mood, appetite, pain perception, fertility, neurogenesis, immune function, body temperature, etc (1).

The ECS is made of three components: receptors, endocannabinoids, and enzymes. Your body uses them regardless of whether you take CBD or not.

An Overview of the ECS Components

Cannabinoid receptors are found all over the body and mediate the effects of endocannabinoids.

Two types of enzymes break down endocannabinoids so that they can send their signals to different parts of the body.

Speaking of endocannabinoids, these are your natural chemical messengers that the ECS releases to promote and maintain homeostasis.

Endocannabinoids bind to two types of cannabinoid receptors: CB1 and CB2 (2).

CB1 receptors are mostly found in the brain and central nervous system and control memory, mood, movement, appetite, pain, and coordination.

CB2 receptors appear mainly in the peripheral nervous system, immune system, and blood. When cannabinoids bind to them, they affect immune function, pain, and inflammation.

Unfortunately, modern times and lifestyles have created a hostile environment for the ECS. Since endocannabinoids are short-lived and the body doesn’t store them for later, more and more people suffer from endocannabinoid deficiencies these days.

These deficiencies are associated with modern diseases, such as migraines, type 2 diabetes, obesity, hormonal imbalances, psychiatric disorders, and autoimmune conditions.

Now that’s where CBD comes into the picture.

How Does CBD Work?

A CBD oil bottles on a stone as platform on green background

CBD works by modulating the activity of the ECS.

In plain English, it’s “Bob the Builder.” CBD doesn’t interact with the CB1 receptors in the brain and central nervous system — hence the lack of high. Instead, it signals the ECS to produce more of its endocannabinoids.

CBD also inhibits the FAAH enzyme that breaks down endocannabinoids, making them more available to the body. With more cannabinoids circulating in the bloodstream, your body can use them more efficiently to optimize essential processes and return to homeostasis (3).

On top of that, CBD acts on over 60 molecular pathways, affecting non-cannabinoid receptors as well (4).

What Are the Health Benefits of CBD?

CBD offers various health benefits that contribute to improvements in physical and mental health. It certainly doesn’t work for all the conditions it’s being marketed for these days.

For example, there’s no evidence that CBD cures cancer, and while it has remarkable anti-inflammatory and anxiolytic properties, it won’t make them dissipate unless you address the underlying cause.

People report that CBD helps relieve anxiety and pain and also improves sleep quality.

CBD is known for its ability to enhance stress response by acting on key neurotransmitters involved in regulating emotions like fear, anxiety, pleasure, and arousal.

It can also improve communication between your immune cells so that they properly identify pathogens and protect healthy cells.

Can CBD Treat Medical Conditions?

There’s a growing body of evidence that CBD can help treat some medical conditions, such as epilepsy, chronic pain, depression, anxiety disorders, and insomnia.

Here’s how CBD works for each of these conditions.

How CBD Works for Mood Disorders

CBD works by elevating the levels of anandamide in your brain. Low levels of anandamide are linked to anxiety disorders, depression, and mood swings, so by increasing its concentrations, CBD may help relieve the symptoms; and if the condition stems from endocannabinoid deficiencies, CBD can address the root cause (5).

Like I said earlier, CBD acts on cannabinoid-independent receptors that interact with key neurotransmitters in the brain.

By activating the 5-HT1A receptor, CBD increases serotonin’s availability in the body. Serotonin is responsible for memory, learning, appetite, feelings of happiness, sleep, body temperature, and sexual behaviors (6).

CBD also increases GABA levels in the central nervous system. GABA is an inhibitory neurotransmitter that prevents the nervous system from overexcitation. Sufficient GABA concentrations improve focus, stress response, increases your resistance to distractors, and make you feel calmer (7).

Related: Best CBD Oil for Anxiety & Depression

How CBD Works for Pain

More than 60% of CBD users take it to relieve pain and inflammation (8).

In a 2009 review of the scientific literature, CBD and other cannabinoids were dubbed as “novel anti-inflammatory drugs.” CBD activates CB2 receptors that trigger the release of adenosine, blocking pro-inflammatory cytokines and reducing inflammation (9).

CBD can do it either internally (by reducing systemic inflammation when you take it orally) or locally (when you use topical products like creams and balms).

CBD also works for pain by dampening pain signaling from the presynaptic to postsynaptic nerve ends (10). This effect pairs with the aforementioned increase of anandamide levels in the brain, which bolster your natural pain threshold.

Related: Best CBD Oil for Pain & Inflammation

How CBD Works for Sleep

Sleeping mask and star confettis on light pink and blue background

CBD has a biphasic nature, meaning that low and high doses produce opposite effects.

In low doses, CBD can increase alertness, improve focus, and make you more productive (11). When you take CBD in the morning, you can calibrate your circadian rhythm, especially if your lifestyle causes melatonin deficiencies. Melatonin is your natural sleep hormone that governs your inner clock.

High doses, on the other hand, can make you feel calm and sleepy by reducing blood pressure and slowing down your breath. Doing so helps you enter the first stage of sleep faster (12).

Studies show that CBD may be beneficial for people suffering from REM-stage disorders. The REM sleep stage is when dreams are formed, and memories get cemented (13).

Related: Best CBD Oil for Sleep

How CBD Works for the Immune System

Here CBD reveals its biphasic effects again.

Low doses of CBD produce an immunomodulatory effect. Simply put, they help your immune cells identify pathogens and eliminate them from the body while protecting the healthy cells against damage (14).

High doses work better for acute inflammation and autoimmune conditions because they suppress the immune system. However, unlike conventional immunosuppressants, they act on specific regions of the immune system rather than shutting it down (15).

Related: CBD for the Immune System

How CBD Works for Epilepsy

One of the most groundbreaking discoveries in cannabis medicine is the Food and Drug Administration’s (FDA) approval of Epidiolex for severe forms of epilepsy in 2018 (16).

Epidiolex is the first cannabis drug to receive a green light from the FDA to manage seizures in people with Dravet syndrome and Lennox Gastaut syndrome, both of which are resistant to conventional treatments.

Epidiolex is based on purified CBD that binds to different brain receptors, such as GPR55 and TRPV1. These receptors show abnormal activity in the brain of individuals with epilepsy.

Though rare, the most common side effects of Epidiolex are appetite loss, diarrhea, fatigue, and headaches.

Related: Best CBD Oil for Seizures & Epilepsy

Is CBD Legal?

Yes, although the source of CBD plays a major role in its legality.

In 2018, President Trump signed the amended Agricultural Improvement Act (also known as the Farm Bill) into law. The new bill legalized industrial hemp-derived CBD nationwide.

Hemp-derived CBD products contain less than 0.3% THC on a dry-weight basis, which is also the official limit under U.S. law.

Marijuana-derived CBD is federally illegal because it contains significant concentrations of THC.

However, you can buy it in one of the 21 states that have legalized the recreational use of marijuana. If you use cannabis for medical reasons, there are 38 states with a comprehensive medical marijuana program.

Is It Safe?

CBD is generally safe and well-tolerated by humans. You can take as many as 1,500 mg of CBD daily for several weeks without dangerous side effects.

The WHO considers CBD a safe compound with a similar abuse potential to a placebo.

However, not all CBD products are made equal, and the sooner you learn how to separate the wheat from the chaff, the better.

How to Buy CBD Products

Follow this simple playbook if you want to ensure a well-thought-out purchase every time you shop for CBD oil online:

  • Check the hemp source: Premium CBD oils are made from organic hemp because such plants grow healthy, CBD-rich flowers and are free from contaminants such as pesticides, heavy metals, or mold.
  • Opt for CO2-extracted products: CO2 extraction is the golden standard on the market. It doesn’t require high temperatures or hazardous solvents to produce clean and consistently potent extracts. It’s also more expensive than other extraction methods due to technological requirements.
  • Read Certificates of Analysis (COAs): high-quality CBD products undergo rigorous testing in third-party laboratories. Independent labs analyze the potency and purity of the tested sample, looking for common toxins to ensure the product is safe for consumption. The CoA should always refer to the current product batch.
  • Choose reputable brands: I’m not saying that newcomer brands don’t make high-quality products, but if you’re buying CBD for the first time, choosing reputable companies is a safer bet. You’ll have plenty of time to experiment later.

How Do You Take CBD?

Two bottles on CBD oil with a hemp leaf on the background

CBD comes in several formats, but most commonly, people choose CBD oils, gummies, or vapes.

CBD oil is taken under the tongue. You need to hold it there for about 60 seconds before swallowing to ensure better absorption and faster-acting effects. Oils come with glass droppers for easier and more precise dosing.

Gummies kick in with a slight delay after about 30-90 minutes. That’s because CBD enters the bloodstream through the digestive tract and must first be metabolized by the liver. From there, it’s gradually released into your system, ensuring longer-lasting effects despite slightly lower absorption rates.

Vapes offer the fastest and most effective way to deliver your daily dose of CBD. You can buy special vape pens that are infused with CBD-rich extract; to use the vape pen, place your lips over the mouthpiece, inhale for 2-3 seconds, and slowly exhale the vapor. The effects should be noticeable within minutes and last for up to 3-4 hours.

You can also find CBD topicals, which work best for localized problems such as inflammation, bruises, swelling, and itching. Their absorption rates and onset vary depending on the formula.

Related: How to Use CBD Oil

Does CBD Work Better With or Without THC?

CBD seems to work better with THC. In fact, whole-plant extracts demonstrate 330% higher biological activity than their purified counterparts.

That’s because full-spectrum CBD, which contains trace amounts of THC, evokes the entourage effect.

Here’s what you need to know about this biological phenomenon.

The Entourage Effect

The entourage effect refers to a unique synergy achieved by cannabinoids, terpenes, and flavonoids in cannabis.

Together, these compounds enhance each other’s health benefits and mitigate potential side effects.

The relationship between CBD and THC is the best example of the entourage effect.

CBD works indirectly on CB1 receptors, modulating the psychoactive potential of THC. Animal studies suggest that CBD inhibits the conversion of THC to 11-OH-THC, meaning that CBD may block some of its psychotropic effects.

CBD may also prevent dopamine system disruptions, while THC overstimulates the dopaminergic system. How this mechanism works and what doses of THC negatively affect dopamine are yet to be determined.

That’s why high-THC/low-CBD strains tend to be very psychoactive but last shorter, while high-CBD/low-THC strains are almost non-psychoactive but can still produce a sense of relaxation, balance, and mild euphoria.

Terpenes provide cannabis strains with their unique properties and benefits. For example, strains high in limonene and pinene will give you more energy and improve focus by counteracting the side effects of THC, while varieties high in myrcene and beta-caryopyllene will have an utterly relaxing effect and carry a stronger body load.

The bottom line is that THC enhances the therapeutic potential of CBD, but you don’t need to use high doses to achieve this effect.

CBD Dosing: How It Works

As will all cannabis products, starting low and slow is the best approach to taking CBD. There are several individual factors you need to consider when dosing CBD:

  • Your weight and metabolism
  • Your age
  • Why you’re using CBD and what effects you’re looking for
  • Your individual body chemistry
  • Your overall health
  • Tolerance to CBD
  • Previous experience with cannabis

A qualified doctor will help you understand how these factors affect your optimal dosage range. A consultation with a health professional will also help you avoid potential interactions with other medications.

How Long Does It Take for CBD to Work?

A white sand hour glass on a table and yellow background

How long it takes for CBD to work depends on the potency, the dose, and the route of administration.

The condition you want to treat with CBD will also play a major role in the onset of the effects. For example, people with headaches or spontaneous anxiety will probably experience the benefits sooner than someone with chronic pain or an autoimmune condition.

Here’s how much time CBD needs to kick in by the method of ingestion:

The effects of CBD oil last between two to ten hours. People generally use CBD multiple times to sustain the effects and maximize the health benefits.

Where to Find CBD Products

The best way to find high-quality CBD products is to look for a reputable online store.

While shopping for CBD somewhere near you may sound tempting, online stores offer several perks that you won’t find in traditional retailers.

The benefits include:

  • Lower prices – online stores cut out the middleman, offering better prices for the same quality products.
  • Seasonal discounts – or coupon codes, reward programs, subscription orders, and other smart ways to save money on CBD.
  • Better product selection – you can browse through hundreds of different formulas in the comfort of your home
  • Fresher products – because they don’t stay on the shelves for months before they’re sold.
  • More transparency – you can read customer reviews and look into the CoAs to get a bigger picture of the product quality and the company’s reputation.

Key Takeaways on How CBD Works

CBD works by interacting with the endocannabinoid system (ECS). From there, it operates on more than 65 molecular targets — which explains its therapeutic versatility.

People use CBD to relieve pain, sleep problems, anxiety, depression, epilepsy and to strengthen their immune systems.

While the jury is still out on some diseases, current research shows promising results when it comes to using CBD as an alternative or complementary treatment for a wide range of diseases.

And if you don’t have any health condition, you can use CBD products to optimize the ECS and bolster your first line of defense against free radicals and the negative impact of stress.

No matter how you choose to take CBD, always make sure that your products carry valid certificates of analysis to avoid being scammed by fly-by-night companies.


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Nina created following the birth of her second child. She was a science and math teacher for 6 years prior to becoming a parent — teaching in schools in White Plains, New York and later in Paterson, New Jersey.