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Is CBD Really Safe? [Find Out the Truth]

Unlike THC, which is linked with side effects such as heightened anxiety, paranoia, and dizziness, cannabidiol (CBD) is often regarded as ‘safe.’

In March 2018, the World Health Organization (WHO) released a report on the non-intoxicating cannabinoid. It stated that naturally occurring CBD is safe and well-tolerated in humans.

In the report, cannabidiol was not associated with any negative public health effects. Furthermore, it did not induce physical dependence and wasn’t associated with “abuse potential.”

Surely, this means cannabidiol is safe. Unfortunately, this isn’t necessarily true. In this article, we outline the adverse effects associated with CBD. We also highlight the dangers of an unregulated market, including issues with mislabeling and contaminated products.

Is CBD Safe When There Are Adverse Effects?

When the WHO said CBD was well-tolerated, it didn’t mean there were no side effects whatsoever. A review of clinical data published in Cannabis and Cannabinoid Research in 2017 looked into CBD’s adverse effects. It focused on research by Bergamaschi et al. from 2011.

Overall, the researchers found that, in general, CBD’s favored safety profile in humans was confirmed. Most of the studies related to the cannabinoid’s usage in treating psychotic disorders and epilepsy. The most commonly reported side effects were:

  • Diarrhea
  • Tiredness
  • Appetite/weight changes

Other possible adverse effects include:

  • Nausea
  • Vomiting
  • Dizziness
  • Anxiety
  • Dry mouth

Are There Any Serious Side Effects from Using CBD?

While the vast majority of side effects are minor, there are a couple of major concerns. The first includes CBD’s possible propensity to increase liver enzymes. Elevated liver enzymes are a marker of liver inflammation.

A study published in Molecules in 2019 looked at the hepatotoxicity of CBD in mice. The researchers gave 8-week-old mice varying doses of cannabidiol. They tolerated the compound well until they received the highest doses. At this stage, the mice showed clear signs of liver toxicity.


However, what they received was the equivalent of 200mg of CBD per kilogram of body weight in humans. It would require a 154-pound individual (70 kilograms) to consume 14,000mg of CBD. Yet, the study also found that repeated doses equivalent to 50mg per kg of body weight could cause liver toxicity. This equates to using 3500mg at a time for someone weighing 70 kilos.

The huge amounts outlined above do not apply to a real-life scenario as practically no one uses that much cannabidiol. The expense alone is a major obstacle. Even using a value for money CBD product, using 3500mg a day would equate to a daily cost of well over $100.

However, the study has shown that incredibly high levels of CBD could prove harmful. In general, though, the maximum recommended daily level of CBD consumption is 20mg/kg. This would result in 1,400mg of CBD daily for our hypothetical 70-kilo person. At present, there is no evidence of harm coming to those who remain below that limit.

How Much CBD Is Too Much in Humans?

Scientists have yet to find a definitive answer. A review of studies published in CNS Drugs in 2019 found that single doses of 1500mg, 3000mg, 4500mg, and 6000mg CBD were well tolerated. As were multiple doses of 750mg and 1500mg consumed twice daily for six days, with a single dose on day seven.

The researchers also found that epilepsy and tuberous sclerosis complex patients used up to 50mg per kilogram of body weight a day with no serious adverse effects. This is a different outcome from what the Molecules study uncovered.

In epilepsy patients, the main side effects included diarrhea, fatigue, decreased appetite, pyrexia, and somnolence. In tuberous sclerosis complex patients, the main side effects were ataxia, drowsiness, and diarrhea. Moreover, the volunteers consumed CBD at the 50mg/kg/day level for three months.

Should Pregnant Women Avoid CBD?

In 2018, the American Academy of Pediatrics warned women to avoid marijuana during pregnancy. It highlighted potential risks to a baby’s development caused by the drug. In the study it released, the Academy said that CBD also passed through the placental barrier.

The CBD industry is unregulated. Therefore, a disturbing number of CBD products don’t contain what is on the label.

Even if CBD itself proves safe to use during pregnancy, such products may also contain THC. As we discuss later, the CBD industry is unregulated. Therefore, a disturbing number of CBD products don’t contain what is on the label.

Is CBD Safe When There Are Certain Drug Interactions?

Another issue with using CBD safely is its potential to interact with certain medications. This includes some prescription drugs used to treat epilepsy. A growing number of people specifically use cannabidiol for epilepsy and to reduce seizures.

CBD inhibits the cytochrome P450 (CYP450) enzyme. There are over 50 enzymes in this class, but six of them metabolize up to 90% of drugs.

CYP2D6 and CYP3A4 are the most significant enzymes. As CBD interferes with the CYP450 family of enzymes, it could decrease certain drugs’ effectiveness or increase toxicity. Here is a quick overview of drugs that CBD possibly interacts with:

  • Antipsychotics such as Orap
  • Benzodiazepines such as Halcion and Klonopin
  • Antiarrhythmic drugs, including quinidine
  • Opioids such as alfentanil and fentanyl
  • Immune-suppressive drugs such as Remeron
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In most cases, the effects are minimal. However, using a large enough level of CBD could inhibit the CYP450 enzyme’s capacity to metabolize specific drugs. Such an interaction could lead to more serious side effects.

There is also a possibility that CBD can interact with blood thinners. For instance, it could increase the level of the drug Coumadin in the blood.

It is worth adhering to the ‘grapefruit rule’ with CBD. Certain drugs carry warnings not to use grapefruit with them. This is because the furanocoumarins in the fruit interact with CYP450 enzymes.

CBD interacts with drugs similarly, though it is probably even more potent. Therefore, if a drug carries a grapefruit warning, it is best to avoid using it with CBD.

An Unregulated Market Is the Biggest Threat to CBD Users & Their Safety

The WHO specifically said that ‘naturally occurring’ CBD was safe. The trouble is, the CBD industry is poorly regulated in many countries, including the United States. The 2018 Farm Bill legalized hemp production and resulted in states producing cultivation programs and growing guidelines.


The Farm Bill did not legalize CBD federally. Indeed, few states have outlined any specific laws regarding the cannabinoid. Instead, they tolerate CBD and provide little oversight. There are exceptions like New Mexico and Florida, states that have moved to regulate the CBD industry. However, in general, consumers must be wary when choosing CBD products.

Mislabeling Is Rampant

With no oversight, CBD sellers can offer products with no lab reports. This has resulted in a staggering number of mislabeled products.

A study published in Pediatric Neurology Briefs in 2018 analyzed the content of 84 CBD products. The researchers purchased the items online and proceeded to test them. They found that 26% of the products contained less CBD than labeled. Over 40% contained more cannabidiol. Ultimately, only 31% of the products provided an accurate CBD reading.

Testers also found a high enough level of THC to intoxicate children in 21% of the products. Bear in mind that some parents give CBD to their kids for conditions such as epilepsy.

Consumers must exercise caution and only choose cannabidiol from brands that offer independent third-party lab reports.

In 2020, the FDA released a report which showed that too many CBD products remain mislabeled. Details are included in a study published in Missouri Medicine. The Administration tested 102 products at random. Eighteen products contained less than 80% of the CBD level indicated. Meanwhile, 37% contained over 120% of the amount of cannabidiol indicated on the label. Concerningly, almost half the products contained THC.

Unfortunately, the above represent just two of many examples of mislabeling in the CBD industry. Consumers must exercise caution and only choose cannabidiol from brands that offer independent third-party lab reports. Also known as certificates of analysis, this documentation outlines what is inside a product. It also proves that a product doesn’t contain residual solvents, pesticides, insecticides, or other harmful chemicals.

Is CBD Oil Safe?

Proponents of CBD oil claim that it is both safe and effective. The research above suggests it is possible to consume a substantial amount daily without suffering major adverse effects. Therefore, a growing number of people use it for its apparent health benefits.

However, suggestions that CBD oil is safe are based on products from reputable brands. The lack of regulation in the industry means there are question marks over every aspect of it. Apart from misleading labels, CBD products could come from pesticide-laden hemp.

In a bid to save money, a brand may use a solvent such as butane. Unsuspecting customers could consume residual butane along with their CBD oil. Without a COA from a legitimate third-party lab, there’s no way of knowing.

Soil Contamination

Hemp is lauded for its ability to absorb contaminants from soil. The plant’s roots dig deep into compromised soil and absorb any harmful chemicals, along with useful nutrients. This process is known as phytoremediation. There is a suggestion that soil contaminants don’t have time to affect hemp due to how quickly the plant reaches maturity. However, there is little evidence to back up such claims.

A review of studies published in Frontiers in Pharmacology in 2020 outlines the issues surrounding cannabis contaminants. The inaccuracy of CBD product labels is extremely concerning in this instance. The researchers outlined that pesticides, heavy metals, and debris often contaminate cannabisderived products. They said these contaminants were “imminent threats that directly impact public health and wellness.”

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Fungal contaminants could prove fatal. The researchers wrote about a case study where a lung cancer patient used illicitly gained cannabis contaminated with Aspergillus fungi. The patient developed invasive pulmonary Aspergillosis and died 19 days after diagnosis.

Hopefully, the 2018 Farm Bill will improve the regulation surrounding hemp cultivation. Even so, consumers must only use hemp cultivated by licensed farmers, preferably in the United States or European Union.


Ideally, a CBD brand will use CO2 extraction to get the cannabinoids from hemp. Ethanol extraction is considered acceptable if the manufacturer ensures the residual solvent level remains below the FDA’s limit of 5,000ppm. There are also individual state limits.

A study published in Environmental Health Perspectives in 2019 looked at contaminants in cannabis. The researchers point out that solvents used to manufacture solvents can remain in the final product.

Also, while the U.S. Pharmacopeial Convention (USP) has guidelines for 59 solvents, it has none for butane or propane. As such, these petroleum-based solvents remain prominent in low-grade products. Apart from USP limits, states have solvent guidelines too.

If a brand doesn’t use CO2 extraction, ethanol is acceptable, but make sure the COA clearly states the residual solvent level in the product. The third-party lab report should prove that the product contains virtually no molds, heavy metals, aflatoxins, or bacteria.

Is CBD Safe to Purchase?

The other issues surrounding CBD’s safety relates to the legal landscape. The 2018 Farm Bill legalized the growth of industrial hemp with a maximum THC content of 0.3% in the United States. Every state has now agreed to follow the legislation or has had pilot programs approved by the FDA. In Iowa, the last holdout state, farmers can start growing hemp in 2022.

However, CBD itself isn’t legal. Epidiolex, a pharmaceutical drug containing the cannabinoid, is FDA approved, but only for a handful of conditions. Most states tolerate the sale and use of CBD, although the THC limit is 0.1% in Idaho and 0% in Kansas. Also, the FDA prohibits the practice of adding CBD to foods or beverages.

A high percentage of top CBD brands ship products to every state, even edibles such as gummies and chocolate.

Even so, a high percentage of top CBD brands ship products to every state, even edibles such as gummies and chocolate. There are few recent reports of any CBD-related arrests, although there’s always a risk that a police officer will mistake CBD oil for marijuana oil. In any case, it is easy to get products from reputable brands without legal ramifications.

Final Thoughts on Whether CBD Is Safe

There is a disconnect between what the WHO thinks about CBD and the FDA’s stance. While the WHO believes that CBD is safe and well-tolerated, the FDA refuses to legalize it. One exception is a pharmaceutical drug called Epidiolex, which contains CBD. The FDA has approved it for epilepsy and a couple of other conditions.

It seems as if CBD can cause minor side effects such as diarrhea and dizziness. However, these tend to appear in individuals who use extremely large amounts. There is a suggestion that CBD concentrations far above the maximum daily recommendation could result in liver toxicity. This is primarily based on a rodent study. A study on humans revealed that a level of up to 50/mg/kg per day had no serious side effects over three months.

Research also indicates humans can tolerate a single dose of up to 6,000mg. Whether the liver will withstand the consumption of this amount daily is another story, and we don’t have the available studies on humans to answer that question.

Perhaps the biggest issue with CBD’s safety lies not with the compound itself but the industry. At present, there is a scant level of oversight. This has led to a concerning number of low-quality CBD products with inaccurate labeling. Products could contain excessive THC levels or harmful chemicals such as solvents or pesticides.

In summation, CBD appears to be safe when extracted from high-quality hemp. Therefore, consumers should only purchase products from brands that offer third-party lab reports.

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