One-third of Americans have tried cannabidiol (CBD), a once obscure medicinal extract from the cannabis plant, hoping for relief from pain, anxiety, insomnia, and other ills. But even though many of us are purchasing CBD—in oils, gummies, pills, tinctures, so-called “edibles,” and topical creams, lotions, and salves—that doesn’t mean we feel confident about using the products we’re buying.

Fake products abound

There are good reasons why we feel confused about CBD. In a new study published in JAMA Network Open, researchers from Johns Hopkins Medicine tested 89 products and found that only 24 percent were accurately labeled. Along with being mislabeled, it’s possible that products are contaminated with toxins. And clear directions about how to use CBD—the right frequency and optimal dose for your problem—are hard to come by. But it’s possible to choose and use the right product, and get the best possible results. The first steps are knowing what CBD is, how it works, and what it can do for you.

CBD is not marijuana

CBD is one of dozens of cannabinoids in the cannabis plant, a single species with several subtypes: Type 1 produces the psychoactive cannabinoid that triggers the high of marijuana (tetrahydrocannabinol [THC]). Type 2 is a combination of THC and CBD. Type 3, which has been bred since around 2009, mainly produces CBD.

Federal regulations state that if a cannabis plant produces less than 0.3 percent THC by weight, the plant is hemp, not marijuana, and it can be legally used for CBD extracts.

Many benefits

In my practice, I have treated thousands of patients with cannabinoids. I find daily use of CBD extracts can help promote alertness and clear thinking, relieve chronic pain and inflammation, ease anxiety, help with occasional sleeplessness, improve mood, increase resilience to stress, relieve irritability, and enhance performance and recovery from exercise (including post-exercise soreness). I’ve seen that low or moderate doses of CBD help many patients with autism spectrum disorders and attention deficit/hyperactivity disorder. It also reduces anxiety and agitation in people with dementia.

How CBD works

How can one compound have such diverse benefits? One way CBD works is by enhancing the activity of the endocannabinoid system (ECS), an inner network of receptors that are distributed in every tissue and organ throughout the body. The ECS is responsible for maintaining a stable internal environment (called homeostasis) despite stressors from the external environment, like infections, toxins, and injuries. Those internal environments include the immune, cardiovascular, gastrointestinal, musculoskeletal, and nervous systems. This broad, homeostatic action likely  accounts for some of CBD’s ability to help you stay healthy, resist stress, and heal from illness and injury.

CBD also acts on a variety of cellular receptors in the body:

  • adenosine A1, which is involved in  anti-inflammatory, neuroprotective, and neuroregulatory autonomic regulatory effects
  • the dopamine D2 receptor in the brain, which probably accounts for CBD’s anti-psychotic effects
  • the 5-HT1A receptor for the neurotransmitter serotonin, which could explain CBD’s benefits on mood, anxiety, and nausea
  • the TRPV1 receptor, which influences pain transmission and inflammation.

In fact, laboratory studies have identified 65 distinct pharmacological targets in the body for CBD.

Choosing a CBD product

CBD products fall into two main categories: broad or full-spectrum products and isolates.

Broad or full-spectrum products contain some of the naturally occurring compounds from the hemp plant, including legally allowed trace amounts of THC.

When possible, choose a full spectrum product, because animal and human studies show that the full range of constituents in hemp products work together synergistically, outperforming isolated CBD.

Isolates contain CBD and no other cannabis plant compounds. They are good for people who can’t have any THC in their system, like those who are subject to drug tests in states where cannabis is not legal for medical use. (Even though CBD does not create a “high” like marijuana, it can show up in drug tests.)

Look for a product that has a third-party certificate of analysis. This certificate helps guarantee that the product is pure (free of pesticides, heavy metals, solvents, yeast, mold, and toxins) and that the labeling is accurate. Use organically grown CBD products to further ensure safety and quality.

Look for a product with labeling that shows how much CBD it contains—not just in the whole bottle, but in each drop, gummy, pill, or portion. For tinctures, this is milligrams per milliliter (mg/mL); for gummies and pills, it is milligrams (mg).

Find the best dose

For most people, I recommend starting at 5 mg per dose, once or twice daily. If needed, increase your dose by 5 mg every two days until you start to feel beneficial effects. At that point, stop increasing and try staying at the same dose for the next week. For many people, the amount that provides only modest benefits in the first couple of days will, after consistent use, provide more benefit over time. You can resume increasing by 5 mg per dose every other day until you find that a dose increase does not provide any additional benefit. After you find the amount that works for you, if you notice the effects wear off too early in the day, add more doses per day. Two to three daily doses may be ideal. The optimal amount for most  people is 5 to 30 mg per use, one to three times daily. If you’re still not getting results with CBD, you may want to add CBDA to your regimen.

Take each dose with a meal. Studies show that CBD is absorbed up to five times better when taken with food that contains fat or oil. If you’re using CBD drops, place them under your tongue or between your cheek and gums and hold for one to two minutes before swallowing to improve absorption.

If you want to try CBD for sleep, increase your bedtime dosage by two to four times the amount you typically take. For example, if you’re taking 25 mg twice a day, at breakfast and lunch, take a 50-mg dose at bedtime.


CBD uses the same detoxification pathway in the liver as some medications, which means taking CBD could inhibit the breakdown of a drug, making blood levels higher. Ask your doctor to use a drug interaction checker to see if CBD is interacting with a drug you’re taking. If it is, ask your doctor if a lower dose would be safe for you. Another caution: There have been infrequent reports of elevated liver enzymes, a sign of liver irritation, in people taking CBD. If you’re taking more than 100 mg daily, have your liver enzymes checked when you start taking CBD and after one month.

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