• Preclinical and clinical studies suggest that CBD in cannabis plants has broad therapeutic potential(1). Data showed that about 62% of CBD consumers reported using the non-psychoactive compound to alleviate a medical condition. 
  • Epidiolex is the only prescription cannabidiol approved by the U.S. Food and Drug Administration (FDA) in 2018. This CBD-based drug is used to decrease the severity and frequency of seizures(2)
  • Research results provide a rationale for further studies to better understand the potential health benefits of CBD(3). Individuals contemplating using CBD for their medical issues should consult their doctor for expert advice and guidance.

Can CBD Cure an Ailment?

Several studies under controlled trials showed the potential of using cannabidiol (CBD) in alleviating neuropathic pain, sleep disorders, epilepsy, multiple sclerosis symptoms, schizophrenia, anorexia, and inflammation(4).

A study conducted by researchers from the University of Chicago showed how cannabidiol may help stop a SARS-CoV-2 infection in mice and human cells(5).

The researchers also requested to have clinical trials be done to determine whether CBD may be used later as a preventative treatment for COVID-19 in addition to the current list of vaccines for the condition.

The researchers emphasized that using CBD as a possible treatment for COVID-19 can only be made possible by using CBD of high purity and specially formulated doses.

Is There Scientific Evidence for Cannabidiol’s Health Benefits? 

Scientific evidence that showcases the efficacy of CBD can be seen in its purported potential to alleviate symptoms of childhood epilepsy syndromes(6). Examples of these epilepsy syndromes are Lennox-Gastaut syndrome (LGS) and Dravet syndrome.

A study published in Epilepsy and Behavior showed that CBD may reduce the frequency and severity of seizures(7).

The same study also showed that adverse events profile (AEP) scores remained stable despite increases in CBD dosing and decreases in anti-seizure medications.

How Does CBD Work?

Cannabis sativa L. is among the species of herbs from Central Asia used in folk medicine and as a source of fiber for textile production(8).

Hemp (also called industrial hemp) is a botanical class of Cannabis sativa cultivars grown specifically for industrial or medicinal use. Its non-psychoactive effects make it popular in medicinal applications.

Cannabinoids are among the most studied compounds found in the resin produced by the hemp plant. Cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) are only two commonly known cannabinoids.

THC produces the “high” sensation associated with marijuana use. THC content is substantial in medical marijuana (medical cannabis).

The body absorbs CBD and interacts with the neuroreceptors in the endocannabinoid system (ECS).

Cannabinoid receptors then send signals through the cells to regulate pain perception, mood, learning, and memory, maintaining homeostasis(9).

Generally, the CBD delivery method may influence the compound’s onset times, as indicated below(10):

  • Inhalation (vaping): 2 to 15 minutes
  • Sublingual method: 15 to 30 minutes
  • Topical application: 15 to 30 minutes
  • Oral administration or ingestion: 30 to 90 minutes

Uses and Effectiveness of CBD

The baseline doses of CBD are usually in milligrams (mg). However, the dosage may vary depending on the symptoms and condition present. Another factor to consider when determining the CBD dosage is the patient’s weight.

A 2019 study conducted by the University of Minnesota showed increased CBD absorption when taken along with high fatty foods(11). Results showed that the presence of CBD in the body increased by four times.

However, individuals should seek a physician’s advice on the appropriate dosage and the intake frequency before using any CBD products.

In the interest of public health and safety, researchers and lead authors such as Antonio Waldo Zuardi and Francisco Silveira Guimarães have conducted studies to examine CBD’s potential uses and efficacy(12).

Locating published results on CBD studies is easy using search engines like Google Scholar and PubMed. Publishers use a DOI (digital object identifier) to identify an article, published study, or ebook.

Studies have shown that CBD may be used as adjunctive therapy to reduce the symptoms of a wide range of medical conditions, including the following:

1. Anxiety 

Aside from alleviating symptoms of epilepsy, CBD may help reduce anxiety when taken along with another antidepressant.

Anxiety disorders are a common type of mental health condition. Types include generalized anxiety disorder (GAD), panic disorder (PD), and social anxiety disorder (SAD).

In a study conducted on 72 adults with anxiety disorders, anxiety scores decreased in 57 patients during the first month(13). The decrease continued for the entire duration of the study.

Depression is also one of the disorders in psychiatry that may benefit from CBD by regulating depressive-based behaviors(14).

Since the mainstreaming of CBD products on the market, doctors are also looking into the possibility of recommending them for pediatric use to help children focus, keep calm, and sleep(15).

2. Post-Traumatic Stress Disorder (PTSD)

The Journal of Alternative and Complementary Medicine conducted a systematic review in 2018 that showed a decrease in post-traumatic stress disorder (PTSD) symptoms in patients after receiving CBD(16).

CBD was combined with THC during the study to create an “entourage effect.” The “entourage effect” happens when the formulation, potency, and benefits of CBD and THC complement one another.

3. Amyotrophic Lateral Sclerosis 

Amyotrophic lateral sclerosis (ALS) patients may benefit from the entourage effect of consuming THC combined with CBD.

According to the study, by introducing exogenous cannabinoids such as THC and CBD, there is a possibility of delaying or slowing ALS progression(17).

4. Diabetes

Clinical studies conducted on a placebo-controlled pilot study indicated that CBD may help patients with diabetes with the level modulation of hormones related to insulin(18).

5. Neurological Disease

Studies show that CBD may possess anti-inflammatory, antigliosis, and neuroprotective properties(19).

Studies are still ongoing to examine how CBD may provide a wide range of benefits to patients with Alzheimer’s disease and Parkinson’s disease.

6. Arthritis

As an anti-inflammatory and analgesic, CBD may serve as a pain relief for chronic pain and stiffness(20). A topical CBD can be used to help alleviate the symptoms of arthritis.

7. Cancer

Scientific research has indicated that different cannabinoids may cause cell death, stop blood vessel development, reduce inflammation, block the growth of cells, and limit the cancer cell’s ability to spread(21).

Meanwhile, research is ongoing on the potential of CBD to be used with chemotherapies and radiation therapy.

Is CBD Safe?

The Farm Bill passed in 2018 allowed the use of hemp under stricter restrictions and the production of hemp for research and study purposes(22).

In addition, the bill removed CBD and other products derived from hemp under the Controlled Substances Act, improving the safety profile of CBD.

As the CBD industry grows, a wide range of CBD products has become available in different forms, from topicals and gummies to tinctures and vapes.

Legal CBD products contain the allowed level of THC, which is 0.3% or lower. Any product with a THC concentration higher than 0.3% may result in euphoria or intoxication.

A commonly known form of CBD product is CBD oil extracted from the cannabis plant and combined with other components.

As a tincture, CBD can be taken orally by putting drops under the tongue.

Other popular CBD products are moisturizers and creams used topically.

High-quality CBD products can be purchased over the counter, online, or at dispensaries of cannabis products all around the United States.

Consumers, however, are advised that CBD products are mainly used as a supplement and not as a medication. There have been no approved dietary supplements that contain CBD.

Other CBD products to avoid on the market are those that have been manufactured by companies not duly licensed to sell CBD products.

Consumers should ensure to buy only from trusted, legitimate brands that use third-party laboratories to test their products for potency and purity.

CBD Side Effects

The effects of cannabidiol are dry mouth, sleepiness or drowsiness, diarrhea, decreased appetite, and mood changes(23). Mood disorders can cause behavior and mood changes and may include agitation and irritability(24).

During clinical trials conducted on patients with LGS and Dravet syndrome, side effects included fatigue, rash, malaise, and infections(25).

There have been no reported severe side effects in individuals who use CBD as a supplement. Still, more research is warranted to understand better the pharmacology of CBD.

Interactions With Other Medications 

There are contraindications when CBD is taken along with other medications. Thus, it is best to consult a physician before taking any CBD product.

Other interactions on herbal products, supplements, and over-the-counter medications can occur.

According to Harvard Health Publishing, researchers in a study identified 139 drugs that may have contraindications with cannabinoids(26). Included in the list were some antibiotics and heart medications.

For 57 of these medications, altered concentrations can be fatal. Some drugs may be affected by the THC concentrations of some CBD products only and not by CBD and vice versa.

The side effects of CBD use include drowsiness. Taking this cannabinoid and other medications with the same side effects can lead to increased sleepiness and fatigue.

When CBD is also taken with stimulants, an individual’s appetite may decrease. Meanwhile, an increased risk of diarrhea may occur when CBD is taken with metformin or specific heartburn drugs such as Prilosec(27).

Another effect of CBD, when taken with other drugs, is the possibility that the non-psychoactive compound may interfere with enzymes in the body, resulting in the inefficacy of adjunct medications.

Special Precautions and Warnings 

While some studies show that CBD may help prevent fatty liver caused by non-alcoholic fatty liver disease (NAFLD)(28), other research shows that CBD may cause liver injury(29).

Furthermore, the FDA warns pregnant women against the use of CBD products, especially those that contain THC(30). THC stays up to six days in a mother’s breast milk and may affect the brain development of a newborn.

Aside from THC, some untested CBD products may contain contaminants such as heavy metals, pesticides, and fungus. Thus, it is necessary to check the product labels and content for THC or CBD before purchase.

Manufacturers usually make the certificate of analysis (COA) of a particular CBD product available on their website. A COA is a lab test result conducted by an independent laboratory.

The accredited laboratory certifies the potency, purity, and content of the CBD product and ensures there are no contaminants present during pre-and post-packaging processes.

Meanwhile, several animal studies on CBD showed how the CBD may cause fertility damage in a male offspring(31).

Is CBD an Answer to the Opioid Epidemic?

A short-term study indicated how CBD oil may help manage triggers for anxiety and cravings in individuals who have a heroin use disorder(32).

CBD may also significantly reduce the salivary cortisol levels and the resting heart rate of patients with substance use disorders. Meanwhile, no serious adverse effects manifested and no significant effects on cognition.

The inhibitory effect of CBD may also help lower cravings for cannabis, opiates, and alcohol. However, studies are still ongoing on CBD as a less risky approach to pain management in heroin-abstinent individuals.

Before trying CBD for any medical condition, individuals should first consult their doctor for guidance and dosing advice to achieve maximum CBD efficacy for health care.


  1. A Cross-Sectional Study of Cannabidiol Users
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6043845/
  2. Epidiolex As Adjunct Therapy for Treatment of Refractory Epilepsy: A Comprehensive Review With A Focus On Adverse Effects
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6396837/
  3. A Cross-Sectional Study of Cannabidiol Users
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6043845/
  4. Cannabinoid Delivery Systems for Pain and Inflammation Treatment
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6222489/
  5. Researchers Recommend Clinical Trials for CBD to Prevent COVID-19 Based One Promising Animal Data
    https://www.uchicagomedicine.org/forefront/research-and-discoveries-articles/researchers-recommend-clinical-trials-for-cbd
  6. FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy
    https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-comprised-active-ingredient-derived-marijuana-treat-rare-severe-forms
  7. CBD oil study shows significant improvement in patients with treatment-resistant epilepsy
    https://www.uab.edu/news/research/item/9665-cbd-oil-study-shows-significant-improvement-in-patients-with-treatment-resistant-epilepsy
  8. Cannabis Sativa: The Plant of the Thousand and One Molecules
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4740396/
  9. Cannabinoid Receptors in the Central Nervous System: Their Signaling and Roles in Disease
    https://www.frontiersin.org/articles/10.3389/fncel.2016.00294/full
  10. Page 190-193 of Healing With CBD
    https://drive.google.com/file/d/1AGlxnhS2SoFeOXEuysv75bd_C9pEnwsU/view
  11. High Fat Foods Can Increase CBD Absorption Into The Body
    https://twin-cities.umn.edu/news-events/high-fat-foods-can-increase-cbd-absorption-body
  12. A Cross-Sectional Study of Cannabidiol Users
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6043845/
  13. Cannabidiol in Anxiety and Sleep: A Large Case Series
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/
  14. The Impact of Cannabidiol on Psychiatric and Medical Conditions
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7331870/
  15. CBD: What Parents Need to Know
    https://childmind.org/article/cbd-what-parents-need-to-know/
  16. Cannabidiol in the Treatment of Post-Traumatic Stress Disorder: A Case Series
    https://www.liebertpub.com/doi/10.1089/acm.2018.0437
  17. Study protocol for a randomised, double-blind, placebo-controlled study evaluating the Efficacy of cannabis-based Medicine Extract in slowing the disease progression of Amyotrophic Lateral sclerosis or motor neuron Disease: the EMERALD trial
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6858175/
  18. Efficacy and Safety of Cannabidiol and Tetrahydrocannabivarin on Glycemic and Lipid Parameters in Patients with Type 2 Diabetes” A Randomized, Double-blind, Placebo-Controlled, Parallel Group Pilot Study
    https://pubmed.ncbi.nlm.nih.gov/27573936/
  19. Cannabidiol in Neurological and Neoplastic Diseases: Latest Developments on the Molecular Mechanism of Action
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8122338/
  20. CBD for Arthritis Pain: What You Should Know
    https://www.arthritis.org/health-wellness/healthy-living/managing-pain/pain-relief-solutions/cbd-for-arthritis-pain
  21. Cannabidiol (CBD) AS A Promising Anti-Cancer Drug
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7693730/
  22. Hemp Production and the 2018 Farm Bill
    https://www.fda.gov/news-events/congressional-testimony/hemp-production-and-2018-farm-bill-07252019
  23. What are the benefits of CBD — and is it safe to use?
    https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/is-cbd-safe-and-effective/faq-20446700
  24. Mood Disorders
    https://my.clevelandclinic.org/health/diseases/17843-mood-disorders
  25. FDA Approves First Drug Comprised of an Active Ingredient Derived from Marijuana to Treat Rare, Severe Forms of Epilepsy
    https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-comprised-active-ingredient-derived-marijuana-treat-rare-severe-forms
  26. CBD and Other Medications: Proceed with Caution
    https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743
  27. CBD and other medications: Proceed with caution
    https://www.health.harvard.edu/blog/cbd-and-other-medications-proceed-with-caution-2021011121743
  28. CBD Alleviates Liver Injuries in Alcoholics With High-Fat High-Cholesterol Diet Through Regulating NLRP3 Inflammasome–Pyroptosis Pathway
    https://www.frontiersin.org/articles/10.3389/fphar.2021.724747/full
  29. What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-Derived Compounds, Including CBD
    https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis
  30. What You Should Know About Using Cannabis, Including CBD, When Pregnant or Breastfeeding
    https://www.fda.gov/consumers/consumer-updates/what-you-should-know-about-using-cannabis-including-cbd-when-pregnant-or-breastfeeding
  31. What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-Derived Compounds, Including CBD
    https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis
  32. Cannabidiol for the Reduction of Cue-Induced Craving and Anxiety in Drug-Abstinent Individuals with Heroin Use Disorder: A Double-Blind Randomized Placebo-Controlled Trial
    https://ajp.psychiatryonline.org/doi/10.1176/appi.ajp.2019.18101191
CBD Clinicals is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more