CBD Oil: More than a dietary supplement, also a drug

(February 20, 2019; updated May 15, 2020)

What is CBD Oil?

Cannabidiol (CBD) is one of more than forty "cannabinoid" chemical compounds present in cannabis sativa plants, which include marijuana and hemp. A cannabinoid known for its psychoactive effects is tetrahydrocannabinol (THC). Unlike THC, CBD is not psychoactive and therefore does not alter a user's mental state. CBD oil can be extracted from either marijuana or hemp.

Most CBD-containing items on the market today are derived from hemp, and are incorporated into a variety of products, including oils/tinctures (probably the most popular), capsules, massage creams, chews, edible films, vaping fluids, beverages, and food. Even though it is usually made from hemp, CBD oil is not the same as hemp oil, which is extracted from the seeds and contains little or no CBD.


Last year, the FDA approved GW Pharma's Epidiolex drug, an oral CBD solution used to treat seizures associated with two rare forms of childhood epilepsy. CBD is not approved for any other uses in the U.S., but GW Pharma has received clearance to study it for other indications, including cancer pain. GW Pharma's "Sativex" drug (which contains both CBD and THC) has been approved for use in Canada, UK, Spain, and other countries and treats muscle spasm in patients with multiple sclerosis (M.S.). It also has been approved in some countries to treat pain.

It is likely that in the U.S., these and other FDA-approved uses of CBD will be available soon. Meanwhile, hundreds of online retailers are marketing CBD oil with disclaimers about specific health benefits.The disclaimers are a way for the companies to avoid receiving a warning from the FDA, but it is unknown how exactly the FDA will respond to the exploding number of companies and CBD products that have become available.

CBD Oil Prescription Epidiolex
Photo of prescription Epidiolex (cannibidiol). Source: Greenwich Biosciences.

The most popular use of CBD seems to be as an anti-inflammatory. Many users suggest that CBD has a therapeutic effect on chronic pain by relieving inflammation. A mouse study from 2012 found that CBD was highly effective at reducing both inflammatory and neuropathic pain. Importantly, its efficacy did not diminish with repeated administrations, as is often the case with analgesics. The researchers found that injecting CBD into the spinal canal provided the greatest benefit.

Several studies have also found evidence that CBD can reduce many types of anxiety including: social anxiety, obsessive-compulsive, and generalized anxiety disorders. Finally, there is preclinical evidence that CBD can help treat addictions like smoking, though more thorough research is needed.

Regulatory: Good News and Bad News

The December 2018 passage of the Farm Bill explicitly removes industrial hemp-derived products from the DEA's controlled substances list. CBD companies, not surprisingly, are overjoyed. They predict increased availability of cannabinoid products for consumers and also much easier access for health researchers. The FDA, however, issued a "not so fast" kind of statement in reference to the Farm Bill, with a regulatory perspective of implications for CBD products marketed as medicinal treatments or as dietary supplements.

Overall, there appear to be few risks involved with taking CBD oil, but the major hurdle seems to be finding a reputable source for these products, as it is still an unregulated industry. In fact, in addition to sending a small number of warning letters in 2017 to companies that market CBD, the FDA tested some products and found that many do not have as much, if any, CBD as claimed. States that have legalized recreational and medical cannabis tend to have tighter control over product testing, but still carry no guarantee of getting what you pay for. Independent lab testing reports for the products are often available, and consumers should check for them.

The take-away of all this for potential CBD oil consumers: Buyer Beware. Check with your doctor, pharmacist, or a trusted health care professional. Ask what they themselves or their patients have used, for how long, the formulation, strength, and any other advice.

Is the retail CBD the same or as strong as the Rx Epidiolex?

The chart below compares key information about retail dietary supplement CBD oil products with the new FDA prescription-only drug called Epidiolex. The active ingredient is the same: cannabidiol. However, retail CBD oil is derived from hemp version of the cannabis sativa plant, while Epidiolex is derived from the marijuana sativa plant.

One of the most notable comparisons is the variation in strengths of CBD available to consumers at retail outlets. Consumers can purchase 30 ml (one ounce) bottles of CBD oil tinctures that range from a $29 bottle with a concentration of 5 mg/ml (150 mg in an ounce of product), to a $165 bottle containing 60 mg/ml, or 1,800 mg in an ounce of product. Just within the past six months, maximum strength products (60 mg of CBD per ml) have become available at brick and mortar stores (such as organic food stores and health stores) nationwide. Though the maximum strength 60 mg/ml formula is strong, the prescription drug Epidiolex has almost double the potency: 3,000 mg of CBD in a one ounce (30 ml) container (100 mg/ml), at a cost of $1200.  While expensive, most patients will have a much lower out-of-pocket cost for the prescription version. 

CBD Oil non-Rx retail products
compared with Epidiolex
Dietary Supplement CBD Oil
Epidiolex (Cannabidiol)
Availability in U.S. Widely available online and at specialty health stores
(for now)
Rx only
Treats* Many ailments including pain, anxiety, nausea, movement disorders, insomnia Seizures associated with two kinds of rare pediatric epilepsy: Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS)
Suggested Use on
Product Label
*Because of lack of FDA approval, labels often have disclaimer that the product is not intended to treat any condition, and are for "general wellness." See above.
Patient Age Most products recommend age 18 and up Age 2 and up; most patients are young children
Company Hundreds of products and retailers in the US and worldwide; U.S. products often described as organically grown and processed. GW Pharma (U.K.) U.S. distributor: Greenwich Biosciences, Inc.
Shelf Life 12-24 months unopened 12 weeks after opening; stored at room temperature
Packaging Usually sold in 30 ml (1 ounce) bottles with 1 ml syringe 30 ml (1 ounce) with 5 ml oral syringe
Flavor Variety; mint, berry, citrus Strawberry
Cannabis plant type used Hemp Marijuana
THC ("high" chemical) no THC no THC
common dose is 1 ml (one dropper) administered under tongue; once a day based on patient's weight; administered twice daily in cheek; maximum maintenance dosage is 20 mg/kg/day
When introduced At least five years ago October 2018; approved June 2018
Side Effects Well-tolerated; may cause sleepiness; diarrhea; decreased appetite May cause sleepiness; decreased appetite; liver problems; diarrhea; transaminase elevations; fatigue
Controlled Substance Not if classified as industrial hemp No (was originally a DEA Schedule V drug; status changed in May 2020)
Dependence** None noted No signs according to study cited on drug label
Characteristics Varies; usually pale yellow Pale yellow color
Strength Typical high concentration formula is 50 mg/ml (1500 mg/oz); a low strength formula is 5 mg/ml (150 mg/oz) 100 mg/ml (3000 mg/30 ml)
Number of doses per ounce 30 doses of 1 ml each Varies by patient weight
Cost Varies; from $39 for 250 mg /oz bottle to $200 for "high quality" 1000 mg/oz bottle $1,235 per 3,000 mg/1 oz bottle; estimated $32,500 cost for year of treatment
Chart by AskaPatient®, February 2019
**"In a human physical dependence study, administration of cannabidiol 1500 mg/day (750 mg twice daily) to adults for 28 days did not produce signs or symptoms of withdrawal over a 6-week assessment period beginning three days after drug discontinuation." (from Epidiolex drug label)

Sources and More Reading:

- FDA's December 2018 statement regarding the Farm Bill implications for CBD availability: https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm628988.htm
- A list of warning letters FDA sent in 2017 for CBD oil products: https://www.fda.gov/NewsEvents/PublicHealthFocus/ucm484109.htm

- CBD reduces inflammatory and neuropathic pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3371734/
- Analysis of previous studies finds CBD reduces anxiety in several anxiety disorders: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604171/
- Preclinical evidence that CBD can help treat addiction: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444130/
- FDA finds lower levels of CBD than advertised: https://www.fda.gov/newsevents/publichealthfocus/ucm484109.htm
- Consumer Reports overview of CBD: https://www.consumerreports.org/marijuana/what-is-cbd-what-to-know-about-this-cannabis-product/
- GW Pharmaceuticals (maker of plant-derived cannabinoid therapeutic drugs including Epidiolex) web site: https://www.gwpharm.com/about
- Drug Label for Epidiolex from NIH Daily Med site: Drug label for Epidiolex

Example CBD oil prices presented in this article came from web sites of various online retailers along with sample prices obtained from brick and mortar organic food stores.