Can CBD Oil Cause Headaches? 4 Risks to Know

CBD is now incredibly popular for its health-promoting effects. It has a range of benefits in the mind and body including the ability to lower anxiety, help with arthritis and suppress inflammation. But many fear it can cause or worsen headaches and migraines. As CBD is a potent cannabinoid, it can have unwanted side effects. Studies are showing headaches are not one of these, however. The research indicates CBD and cannabinoids help in preventing and mitigating headache symptoms. They can lower the severity and frequency of migraines. Other side effects can occur such as dry mouth, lethargy or an upset stomach but are typically mild. Few users have had experiences with CBD causing headaches as a side effect. But there are some scenarios where it can occur. Let’s explore when and how CBD oil could cause headaches. We’ll review both whether the risk of headaches is worth worrying about; plus precautions you can take to avoid them.

What is CBD?

CBD is a naturally produced extract from the hemp plant. It activates your endocannabinoid system (ECS), a network of complex cannabinoid receptors that exist throughout the body. These receptors occur in both the organs and tissues of the body, as well as the brain and nervous system. The ECS influences not only metabolic processes but neurological signalling through the GABA and serotonin receptors. Unlike THC, CBD isn’t psychoactive and has no risk of causing mental illness like psychosis. It’s been well-documented for its high degree of safety, non-addictive characteristics and therapeutic properties. 

Dosage ranges are important and alter the effects of CBD. For example at high doses of CBD, cannabinoid receptor type 2 (CB2) within the ECS helps to relax the vascular system and allow blood to flow more easily. This can result in lower blood pressure as a benefit. At low doses of CBD, fewer effects will be felt. These may be experienced as improved calmness and mood. Dosage size affects the benefits of CBD but also influences the risk of side effects. Dosing incorrectly increases side effect risks.

Can it Cause Headaches?

CBD is a very well-understood, researched, and clinically studied chemical with well-known effects. Safety studies would have revealed that CBD had a high likelihood of causing headaches as a side effect. This has not been shown to date. There is no clinical evidence supporting the idea that CBD oil can cause headaches or related conditions like migraines. A comprehensive report published on the safety and effects of cannabidiol by the World Health Organisation was released in 2018. This report researched the side effects of cannabidiol. Some of these included dry mouth, tiredness, diarrhoea, reduced blood pressure and changes in appetite. Side effects are almost always very mild and rarely occur. Headaches were not found to be a common side effect. 

People may consider light-headedness and dizziness a headache, but these are different effects. Typically these are the result of CBD’s effects on lower blood pressure which can stimulate these sensations. The real cause of headaches is not CBD oil itself. Headaches can be caused by environmental and physical factors like stress, caffeine, dehydration, and lack of sleep. Dehydration is a big contributor to headaches which CBD can contribute to. It causes dry mouth and can affect saliva production. Extra water should be consumed when taking CBD to help compensate and ensure adequate hydration is maintained. Genetics and physiology play a big part in the occurrence and frequency of headaches. If CBD oil is taken alongside other drugs, it may result in headaches due to adverse medication interactions. For example, antipsychotic drugs like pimozide are known to negatively interact with CBD. These adverse drug interactions can bring about headaches. CBD is rarely a direct cause of headaches in itself.

Can CBD Solve Headaches?

Despite fears that CBD can cause or worsen headaches, for most users it assists with headache symptoms. Cannabinoids like CBD are analgesics and can help in lowering the pain headaches cause. They assist in reducing the perception of pain by helping to disrupt pain signalling in the nervous system. While it won’t stop all pain completely, this property can assist in reducing the severity and impact of migraine or headache pain. More studies are even being directed towards cannabinoid medication in treating migraines. 

For example, a meta-analysis of studies using medical cannabis to treat headaches and migraines explored 12 publications that had over 1900 individual test subjects. This analysis found medications containing cannabinoids like CBD reduced the severity and frequency of migraines. In close to 12% of patients, it completely prevented migraine symptoms. For 40% of users, it lowered the frequency of migraines. This is hugely promising and indicates cannabinoids prevent, not cause headaches. A separate paper from 2017 showed medications with THC and CBD could help in treating chronic headache symptoms and lower pain symptoms. Overall the evidence from trials to date suggests CBD does not cause headaches.

What are the Risk Factors?

It is important to note that there isn’t a single cause of headaches and CBD is not noted as a major cause. When headaches occur, they’re typically the result of multiple factors which can even include genetic predisposition, lifestyle, health status and underlying mental conditions. Let’s take a look at a few scenarios where your CBD product may contribute to headaches due to factors like contaminants or low-quality CBD products.

Incorrect Dosage

It is crucial to take the correct dosage when it comes to CBD. CBD oil is very easy to administer and may be prone to incorrect dosing by users, leading to a heightened risk of side effects. Although side effect risk is low, it is exacerbated at high dosage levels. This is particularly true for new users who have low experience and tolerance to the cannabinoid. While it is non-toxic, excessively high doses can lead to headaches. If you are a first-time CBD oil user, you need to start with a small dose of around 50 mg per day (several drops), and with time you can gradually adjust the dosage as your body gets accustomed to it. Doing so enables you to gauge any intolerances you may have and pick up on side effects early before they become an issue. 

You can get the optimal dose by consulting a medical professional with experience in CBD. They will prescribe the amount you can take depending on your body weight and health condition. A medical practitioner can also help monitor your body’s response throughout treatment and modify the dosage as needed. Always monitor for signs your body may be reacting adversely and cease using the product if this occurs. Ensure you remain hydrated to avoid any dehydration-related issues.

Association by Proxy

Association by proxy means that a portion of the people who report headaches after using CBD oil was about to experience a headache anyway. In other words, they misattributed their headache to being caused by CBD. You can experience headaches at different pain levels. They range from mildly aching stress to chronic migraines. These different types of headaches could result from light exposure, a bad diet, insufficient food, or even something more serious like a brain tumour. Many factors can result in head pains that people mistakenly blame CBD for. 

Lack of Laboratory Testing

Since the CBD industry is not strongly regulated, consumers need to take particular caution around product quality and should look for third-party lab testing. When you have independent laboratory results, you have objective information that can tell you more about the quality and potency of a CBD oil product. Lab results provide you with a list of all the active ingredients in the product. It should also include warnings of any residual solvents or contaminants within the product. A breakdown of the cannabinoids and their concentrations is also included. It can show the presence and concentration of different cannabinoids like CBD, THC, CBG, CBN, CBDA, and MEB. 

To avoid low-quality products, seek out lab reports or certificates of analysis on your product. There should be test results or certificates of analysis readily available on the seller’s website. High-quality products will offer lab results from testing that show the cannabinoid content, concentration and levels of other compounds like terpenes in the formulation. As they’re from third-party laboratories, they can be relied on to provide accurate and objective information on the quality of your product. They also give assurance your product has been quality assured and doesn’t contain contaminants, additives or residue from solvents. No lab results or an absence of clear labelling is generally a risk factor that your product is not safe or high quality. Avoid buying CBD oil from a company that does not disclose laboratory findings. CBD that is not well-labelled may have side effects, including headaches. It can contain contaminants like solvents used to extract the oil, which is harmful to ingest.

Besides the third-party tests, aim to buy CBD oil that has been CO2 extracted. No unnecessary solvents, oils, or fillers will be added during this extraction method. The risk of accidental contamination is reduced. CO2 extraction uses carbon dioxide gas only to pull the CBD out of the hemp plant it’s sourced from. No harsh solvents are used during this extraction method like ethanol. Even trace levels of residue from solvent-based extraction left in the final product can be harmful to your health and cause headaches.

Contaminated Products

Cannabis plants from which CBD is extracted are grown in different parts of the world and under different conditions. For example, if the soils the plants are grown in contain heavy metals like lead, arsenic or mercury, these can be absorbed into the plant. It can subsequently make its way into your CBD product as a contaminant. Soil and environmental pollutants are major factors in impacting the toxin levels of any natural product sourced from plants.

The way the extract is processed can also have an impact. If your CBD oil was processed in a location that also handles heavy metals, toxic materials or artificial ingredients these can cross-contaminate your product. There is a real possibility for toxic chemicals to accidentally make their way into your CBD oil. For example, if the plants are grown in an area with soil contaminants like arsenic which can be absorbed into the plant and resulting extracts. Cannabis plants are susceptible to absorbing lead, mercury, and other chemicals. The absorption of these toxic heavy metals can ultimately cause severe impacts on your health – including headaches, migraines, or cardiovascular damage. Be wary to only purchase CBD sourced from organically farmed hemp plants that are toxin-free.

Low-Quality CBD Oil

There is a wide spectrum of product quality levels when it comes to CBD oils available today. The difference between a high and low-quality CBD product is significant and has implications when it comes to factors like side effect risk. Low-quality products are more likely to use filler additives, contain low cannabinoid content and have artificial flavours or preservatives added to them which have detrimental health effects. Some will even use synthetic or fake ingredients to cut costs. These can exacerbate allergies, and cause headaches and other health risks if consumed. Carrier oils used in the product can also impact headache risk. Some people are allergic to specific carrier oils and this can be worsened if the carrier oil is low-grade or degraded. 

Avoiding Headaches from CBD

While headaches won’t be caused by CBD directly, you can minimise any risk of it occurring by dosing at low amounts initially. Low dosages mitigate the potential of side effects and help to reveal whether you tolerate CBD well. It can also help to identify whether any issues occur with your product from contamination with THC or other adulterants that can exacerbate side effect risks and cause health concerns. Ensure your product comes from a reputable supplier to minimise risk. Reviews from customers and certifications like GMP can help indicate whether a product is an effective and low risk of causing headaches. Pure CBD products won’t result in any issues but those that are low quality certainly can.


The clinical evidence indicates CBD isn’t a risk factor in causing or worsening headaches and migraines. In fact – the opposite is true. Cannabinoids can help in mitigating the severity, frequency and symptoms of painful headaches. But this is only true when they’re sourced from pure, high-quality products. Low-quality products can cause headaches. This isn’t due to CBD itself but rather contaminants that these products can contain like solvent residue, artificial additives, fake ingredients and pesticides. If the product was sourced from low-quality plants it may also contain heavy metals or toxins that create a risk of headaches. Additionally, mixing CBD with other medications is not advised and could also result in headaches. When you take CBD at the right doses and select first-class products, the risks are minimal. In all cases, it’s highly recommended to consult with a healthcare provider before using any new supplement like CBD.