All Your CBD Questions Answered by a Pharmacist

After months of research and reaching out to CBD manufacturers, I decided to put this blog together with answers and information concerning common CBD questions and issues. Let’s start with the easy one:

What is CBD?

You have probably heard CBD mentioned somewhere. The news, web articles, advertisements in a local store—CBD is a hot topic. In some states, you may even see everyday food products being advertised to contain CBD, like gummies, chocolate, and beverages. But what is CBD?

CBD, short for cannabidiol, is one of the molecules of the cannabis family. Despite its name, CBD does not actually have any psychoactive properties, meaning that it doesn’t cause a person to feel the high that is commonly associated with cannabis due to tetrahydrocannabinol (THC).

Research into the human body shows the existence of an endocannabinoid system.  We’re still learning about how this system works in our body, but some theories (many with studies to back them up) argue that the endocannabinoid system, not endorphins, are responsible for the “runner’s high” that people experience after working out.

Researchers also believe that the endocannabinoid system may play a role in memory and the body’s homeostasis – processes that help our body maintain stability. This research has led to the discovery of two endocannabinoid receptors in the human body – CB1 and CB2 – that may potentially help induce relaxation, reduce pain & anxiety, and assist with blood pressure maintenance.[1]

How Does CBD Work in the Body?

Scientists still aren’t certain exactly how CBD works in the body, which makes it difficult to know what it is capable of. Strangely enough, most scientists seem to agree that CBD actually doesn’t work on the CB1 and CB2 receptors, but rather that CBD is responsible for protecting anandamide, the chemical that does activate some of these receptors and may be responsible for the positive effects associated with the endocannabinoid system.

Currently, CBD has only been approved for use by the FDA as a prescription product to treat two rare forms of childhood seizures, but studies are being done to determine what else it may be used for. Some possible uses that are being evaluated include treating pain and inflammation, epilepsy, PTSD, anxiety, Crohn’s disease, multiple sclerosis, graft vs. host disease, and autoimmune disorders. CBD is even being researched as a potential tool to fight opioid withdrawal.[1]

Will CBD make me feel “high?”

CBD is not the same thing as tetrahydrocannabinol (THC), the chemical responsible for producing the “high” that is associated with marijuana use. There was a previous concern that CBD could be turned into THC in the body, but studies have shown that this is not the case. CBD products in the United States are required by law to have less than 0.3% THC in them.

It is important to note this if you are subject to drug testing, as there is still a chance that a urine test may return positive for THC. There are THC-free products out there for people who still want to take CBD but don’t want any THC in their system, but it’s important to find a reliable producer to make sure that you’re getting what the packaging says you’re getting. Make sure to check if any product you’re interested in comes with a Certificate of Analysis (explained more below).[1]

How Much CBD Should I Take?? What Should I Expect in Terms of Side Effects? Can I Take CBD Instead of My Other Medications?

Let’s take these questions one at a time.

How Much CBD Should I Take?

With the exception of the FDA-approved CBD product Epidiolex (used to treat seizures), there are no established dosing recommendations of CBD. We don’t yet know what doses and dosage forms work best for different conditions, making dosing recommendations at best, a guess. Despite this, studies have shown that single doses up to 6000 mg result in very few documented negative side effects.[2]

What Side Effects Should I Expect From CBD Therapy?

The most common side effects demonstrated in studies include fatigue, weight loss, difficulty sleeping, nausea, and diarrhea, but many people reported no side effects at all.

Current research into how CBD works in the body points to twice-daily dosing of oral forms of the drug. Studies have also shown that oral forms of the drug are best absorbed by the body when taken with a high-fat or high-calorie meal. This is not a recommendation–it is just what preliminary research shows. As always, talk to your doctor or pharmacist before starting any CBD regimen.[2]

Can I Take CBD Instead of My Prescriptions?

Some people have reportedly stopped taking doctor-prescribed medications to take CBD instead with the hopes that it will be more effective. It is extremely important to remember that CBD available over the counter is not a suitable replacement for prescription medications.

While there are many studies being done on the benefits and effects of CBD, it has not been approved to diagnose, treat, or cure any disease by the FDA (not counting Epidiolex). CBD is not held to the same testing and safety standards that prescription drug products are.[2]

Are there any interactions between CBD and prescription drugs?

Some people think that because CBD is derived from something “natural” that it won’t have any interactions with prescription drugs. This is not true. Like many medications, CBD is metabolized (broken down) by the liver. This means that it can interfere with the body’s natural ability to process and break down certain drugs.

Prescription medications or other supplements you take that interact with CBD could, therefore, be present in your body in increased or decreased amounts than what they are intended to be. Why does this matter? Depending on the medication and the interaction, you could be at risk for experiencing more side effects or not getting the full benefits of your medication.

Since CBD is metabolized by the liver, it may not be ideal for people with liver problems. Again, CBD has not yet been fully studied, so it is possible there are still more drug interactions that we don’t yet know about.[3]

Known CBD Interactions

  • CBD can increase the body’s levels of citalopram (Celexa), warfarin (Coumadin), and other drugs that are called central-nervous-system (CNS) depressants, including some anti-seizure medications.
  • CBD can decrease the levels of clopidogrel (Plavix) in the body.
  • Other drugs can also affect the levels of CBD in the body (not just the other way around)[3]

What about the law? Is CBD legal in Illinois? What does the FDA say?

Unfortunately, the law has continued to be fuzzy, despite federal legalization of CBD derived from hemp products by the 2018 Farm Bill.  CBD in topical and cosmetic forms – such as creams, topical sprays, ointments, salves, etc – are legal. CBD has already been approved as a prescription-only drug called Epidiolex, which means that over-the-counter CBD products in oral supplement form (think capsules, gummies, foods infused with CBD and the like) are still technically illegal, even though it seems to be available everywhere. I drove past a local video store the other day and saw they were advertising CBD gummies!

It is important to be wary of products or companies that make claims about what CBD can do. As I said before, CBD has only been approved to treat two types of seizures, and companies that make claims about it being able to treat anything else are making these claims illegally.[4]

While doing my research into CBD product lines and companies, I saw a brand that claimed CBD can help cure cancer. Not only has this not been proven, but it is also illegal for a company to say this about their product.[5]

Make Sure You Get the Right Amount of CBD in Your CBD

Another thing to be on the lookout for is the number of products that do not contain the amount of CBD the label says. A 2016 study examined how accurate the labels on some CBD products available over the Internet were. 84 different products including oils, vaping liquids, and tinctures were obtained from 31 different companies.

A shocking 69% of products examined were mislabeled – meaning they either had more or less CBD than was advertised. Only 31% of products were accurately labeled. To avoid buying a product that is mislabeled, see if the company offers a Certificate of Analysis (COA) for their products. Brands that obtain a COA should be able to provide you with specific information regarding how much CBD and other chemicals are in their product. CBD products with a COA will also list when testing was done and the manufacturing date of each product.[5]

What A Pharmacist Thinks You Should Know About CBD

Here are the key points that CBD-curious people reading this article should remember:

  • Only one product is approved by the FDA. It’s called Epidiolex and it is approved only for treating two different types of seizures. Otherwise, over-the-counter CBD products are not approved to diagnose, treat, or cure any diseases. There are many potential uses for CBD that are currently being studied but are not FDA approved.
  • Do not stop taking your prescription medication to take CBD products – this could be dangerous to your health
  • Make sure the CBD product you’re getting comes from a reliable source. Be aware that there are companies out there making false claims about the contents of their products and what CBD can do. There are a lot of mislabeled products out there.
  • CBD has many potential drug interactions. Ask your doctor or pharmacist about interactions before buying any CBD product if you take any prescription medications.

Drawing Conclusions About CBD (for now)

I’ve been seeing a lot of advertisements online recently claiming that CBD is a new miracle cure-all without any side effects. As much as I would love for this to be true, there just isn’t enough evidence to prove that it is effective in treating everything people claim. There are already known side effects associated with CBD, which may not mix with every person’s body chemistry.

CBD, however, is being studied for other possible uses besides it’s two FDA-approved indications and we are learning more about it every day.  It’s definitely possible that in the near future we will have a better understanding of how CBD works in the body leading to more legitimate uses for it, which is an exciting prospect!

As always, if you have any questions about CBD, feel free to stop by our pharmacy and ask one of the pharmacists, or send me an email for more references and information.


  1. Sigman, Zoe (2019). What is CBD Oil? A Primer for the “It” Medicine of the Moment. Retrieved from
  2. Taylor, L., Gidal, B., Blakely, G., Tayo, B., & Morrison, G. (2018).  A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose, Multiple Dose, and Food Effect Trial of the Safety, Tolerability and Pharmacokinetics of Highly Purified Cannabidiol in Healthy Subjects. CNS Drugs. 2018; 32(11): 1053–1067.
  3. Brown, J., & Winterstein, A. (2019)  Potential Adverse Drug Events and Drug-Drug Interactions with Medical and Consumer Cannabidiol (CBD) Use. J. Clin. Med. 20198(7), 989.
  4. FDA (2015-2019).  Warning Letters and Test Results for Cannabidiol-Related Products. Retrieved from FDA Warning Letter Archive.
  5. Bonn-Miller, M., Loflin, M., Thomas, B., Marcu, J., Hyke, T., & Vandrey, R. (2017).  Labeling Accuracy of Cannabidiol Extracts Sold Online. JAMA. 2017 Nov 7; 318(17): 1708–1709.

Further Reading

Disclaimer: Statements in this article have not been evaluated by the FDA. CBD is not intended to diagnose, treat, or cure any disease.

Written by Hannah, PharmD

Hannah started working for Oswald’s Pharmacy in 2018. Hannah is a pharmacist focused on service and pharmacy innovation.