CBD is all the rage these days, but there’s a lot of confusion about how best to use it. Dosages vary dramatically; many CBD edibles contain only 5 mg of CBD, while experienced users frequently use more than 10 times that much. That can make CBD dosing very confusing, even for experienced users.
There is no standardization of CBD dosing, nor is there an FDA-recommended dose. The optimal CBD dosage varies from one individual to another, and finding the right dose for you requires some self-experimentation. The process works something like this:
- Identify the benefits you hope to get from CBD
- Decide which form of CBD you want to use
- Determine your optimal dosage and timing based on bodyweight, form of CBD used, and the half-life of CBD
- Manage side effect
CBD Half-Life and Onset of Effects
The elimination half-life of CBD in human beings ranges from 18 to 32 hours. That means that once you take CBD, it can continue to affect you for days afterward.
That said, the active life of CBD—the duration for which you’ll truly feel the effects—is much shorter.
Inhaled CBD typically has an active life of around two hours, while ingested (eaten) CBD lasts for upward of four hours. The difference is because ingested CBD takes much longer to be fully absorbed into the bloodstream, requiring up to several hours to fully digest.
The onset of effects varies even more widely depending on the form of CBD used. Ingested CBD will typically take effect within 30 to 90 minutes, while inhaled CBD takes effect within 1 or 2 minutes.
Which Conditions Can Be Treated with CBD?
CBD is used to treat a number of different conditions ranging from chronic pain to anxiety. The condition you’re treating with CBD needs to be taken into consideration when deciding to use this substance. Three factors in particular are dependent on the condition you’re treating: your optimal dosing, the form of CBD you use (ingested versus inhaled), and the optimal ratio of CBD to THC.
CBD is used for a wide variety of conditions, including cancer (both cancer itself and the side effects of anti-cancer medications), nausea, high blood pressure, schizophrenia, epilepsy, and autism. I won’t go into detail on all of those conditions, but I will cover the four most commonly treated ones — chronic pain, anxiety, depression, and insomnia.
The research on CBD for the treatment of insomnia is rather more positive than the research on its applications for pain management, finding that CBD is indeed effective at treating insomnia.
The same research also shows that CBD is more effective at treating insomnia and has fewer side effects compared to THC. In other words, people using CBD for insomnia should pick a formula that has a very high CBD-to-THC ratio.
CBD has an additional advantage over sleep aids such as SSRIs, Ambien, and benzodiazepines in that it does not alter the normal sleep-wake cycle — in other words, it doesn’t increase sleep quantity at the expense of sleep quality, and it shouldn’t make you groggy the next day as long as you use the minimum effective dose.
There is one other consideration for insomniacs — whether they suffer from onset insomnia (i.e., difficulty falling asleep) or sleep-maintenance insomnia (i.e., waking up in the middle of the night or too early in the morning).
For onset insomnia, a vaporizer or oral spray is likely preferable, since it produces a faster and more pronounced peak in effects that will “knock out” a user more effectively. Ingested CBD, while coming on more slowly and producing less of a peak in effects, also lasts longer. Those suffering from sleep-maintenance insomnia will therefore be better served by ingested CBD.
Anxiety and Depression
I’ll cover these two together since they often co-occur in the same patients.
A systematic review found substantial evidence that CBD is effective for the treatment of a range of anxiety disorders. The vast majority of the studies included in the review used pure CBD; of the ones that used a mix of CBD and THC, the ratio ranged from 10:1 all the way to 1:1. The study’s authors noted that while it can be concluded that CBD in general is effective for treating anxiety, further research is needed on dosing.
CBD also shows signs of efficacy in the treatment of panic disorder. Early signs suggest that it could be used to treat post-traumatic stress disorder by altering a patient’s feelings about the negative memories associated with PTSD.
There is less research on the use of CBD for depression; what has been published so far looks promising but relies mainly on animal studies. For example, CBD exerts an antidepressant effect in mice. This effect seems to be dependent on serotonin levels; researchers found that applying less than the minimum effective dose of both CBD and a selective serotonin re-uptake inhibitor produced significant antidepressant effects, indicating that the two have a synergistic effect. CBD and SSRI combination therapy could offer a way to realize the benefits of antidepressants with fewer side effects.
It is likely that there’s a second mechanism behind CBD’s effectiveness in treating anxiety: inflammation. CBD is an anti-inflammatory, and chronic inflammation has been shown to be a contributing factor to depression.
For depression or any form of generalized anxiety that tends to be continual throughout the day, you’ll likely want to use a low dose of ingested CBD and to re-dose every few hours. For panic disorder or any sort of anxiety that tends to come in sudden “attacks,” a vape pen will be a better option, allowing you to quickly respond to anxiety attacks as they occur.
The optimal ratio of CBD to THC for these conditions is unclear; since the subjective effects of THC vary substantially between individuals, the optimal ratio may be different for everyone. It’s worth trying a few options—say, pure CBD, followed by 10:1, 4:1, and 2:1 ratios—and seeing which works best for you.
Other Uses of CBD
CBD is currently being investigated for a wide variety of other uses. While all of them are promising, none have been studied to the same degree as the ones previously listed.
- CBD appears to have anti-cancer properties, but it’s not yet clear which forms of cancer it works on, how consistently effective it is, or how well it combines with other cancer treatments. CBD has also been found to be capable of inducing autophagy and apoptosis—programmed cell death—in breast cancer cells.
- CBD has also been found to protect against liver damage, partly by protecting against oxidative stress and partly by inducing autophagy. Autophagy is the process by which your body naturally removes damaged cells—a crucial mechanism for cancer prevention, overall wellness, and human longevity.
- There is evidence that CBD reduces blood pressure, at least in the short term.
- There is some initial evidence that CBD may be useful in treating epilepsy and schizophrenia.
- Finally, there have been promising pilot studies indicating that CBD can improve behavioral measures in children with autistic spectrum disorder.
Forms of CBD and Deciding Which to Use
CBD comes in several forms, including ingestible oils, edibles and capsules, liquids for use in vaporizers, and oral sprays. Regardless of the form you use, the drug will always be the same once it hits your bloodstream. The various forms differ primarily in cost, convenience, and duration and onset of effects, but some side effects may also vary in severity depending on the form of CBD used.
CBD Vape Oil
Vaporizers have the advantage of being the fastest-acting form of CBD, typically taking full effect within one to two minutes. This also makes it easy to titrate — find the correct dose — as you can take a hit from your vaporizer, wait a minute or two, take another hit, and repeat until your symptoms abate.
If you’ve used ingestible forms of CBD in the past, be aware that inhaled CBD also has higher bioavailability than ingested CBD — 1 mg of inhaled CBD will produce blood levels 1.5 to 2 times higher than 1 mg of ingestible CBD will. The dosing can also be somewhat inconsistent, since it depends on how long you hold each “hit” in your lungs.
Just as the effects of inhaled CBD start faster, so too do they end faster: the effects only tend to last two hours, compared to four hours or more for edibles. This may be good or bad, depending on what you’re treating.
Vape oil also tends to be more expensive than edibles. Aside from the fact that you need a vape pen to use it, the oil itself carries a premium, since you will need to use the capsules created by the vape pen company — in other words, it follows the razor and blades business model.
The first of several forms of ingestible CBD is the tincture — a bottle of CBD oil that is meant to be drunk, either mixed with a beverage or placed directly on the tongue.
Like all forms of ingestible CBD, the effects of tinctures come on more slowly and last longer compared to inhaled forms. Because they are liquid rather than solid, tinctures will be absorbed more quickly than edibles and capsules , with onset of effects occurring within as little as 15 minutes.
CBD tinctures have the additional advantage of more consistent absorption from person to person, which means that the dosage that works for one person is more likely to work for another. The CBD can settle at the bottom of the bottle, but this problem can be solved by gently swirling the oil around the bottle before extracting it with the dropper.
Because they’re easier to make, tinctures tend to be the cheapest form of CBD, at around 5 to 10 cents per milligram.
The main downside of tinctures is that you have to be careful in measuring your dose. If the bottle has, for example, 600 mg of CBD and 30 ml of tincture, that means it has 20 mg/ml. You would therefore need half a milliliter to get a 10 mg dosage. Make sure you do this math up front, and that the dropper you’re using has clear markings that allow you to measure your dosage to within a tenth of a milliliter. Also, tinctures are made with high-proof alcohol, and though you typically will only ingest a very small amount, they may not be a good option for you if you abstain from alcohol.
Edibles can include anything from gummies (candy) to cookies to beef jerky. Gummies are the most common form of CBD because they’re easy to make, have a relatively long shelf life, and can be made very small for easy storage and transport. An additional advantage of gummies is that they have fairly even levels of TCH, both from one gummy to the next and within an individual gummy.
Gummies also tend to be the most available form of edible; most dispensaries carry them in a wide variety of dosages and CBD-to-THC ratios. While they’re not quite as cheap as tinctures, they still tend to be fairly cheap overall, at around 10 to 25 cents per milligram.
Gummies are therefore the best option for people who prefer edibles. The absorption speed of gummies lies somewhere in between those of tinctures and capsules.
CBD capsules are relatively uncommon and usually a bit more expensive than other forms of CBD. The big advantage they have is precision of dosing — you know exactly how much CBD is in each capsule.
Capsules also tend to be absorbed more slowly than other ingestible forms of CBD, because you can’t even begin to absorb a capsule’s contents until the capsule itself has dissolved. The onset of action for capsules often takes more than an hour.
Capsules are a good option mainly if you need to be extremely precise about your dosing—such as when mixing CBD with other prescription drugs. Again, be sure to talk to your doctor before doing that.
Oral CBD Spray
Oral sprays are very new and even less common than capsules. The spray is absorbed through the skin on the inside of the mouth, going directly into the bloodstream. This allows for rapid onset of effects, almost as fast as those associated with a vape pen, taking around 2 to 5 minutes.
In practice, however, oral sprays tend to produce a biphasic effect — some of the spray is absorbed into the skin, while some is swallowed. This could potentially mean that they offer a good compromise between the speed of a vaporizer and the long duration of edibles.
Sprays tend to be expensive when they’re available at all, and research on them is lacking. Some studies have found them to be effective in treating multiple sclerosis.
How to Determine Optimal CBD Dosage
Once you’ve decided which form of CBD to use, you can figure out a dosing schedule. That schedule will depend on which form of CBD you’re using, what specific purpose you’re using it for, and what time of day you begin taking CBD.
Determine Your Starting Dose Based on Bodyweight
Although studies have used as much as 300 mg of CBD in a single dose, the “standard” CBD dosage, inasmuch as there is one, is much lower — around 1 to 6 mg of CBD per 10 lbs of bodyweight.
The following dosing chart will keep you toward the lower end of that range—you’ll start with roughly 1 mg per 10 lbs if you consume CBD during the day, or 1.5 to 2 mg per 10 lbs if you wait until the evening.
Safety note: All listed dosages assume that you’re using CBD as your sole medication. If you’re combining it with anything else that might have a synergistic effect — particularly sleep aids, anti-psychotics, anti-spastics, or antidepressants — do not use CBD without first discussing it with your doctor. If you do combine CBD with other medications, cut all listed dosages in half, at least to begin with.
Here’s what each of the labels in the table mean:
Weight: This is your bodyweight.
Daytime Initial Dose: This is what your initial dose — the first dose you take on any given day — should be if you begin taking CBD any time during the day, up until dinner. CBD is a depressant and can make you groggy and uncoordinated during the day, so it’s important to use the absolute minimum possible dose during the daytime.
Evening Initial Dose: This is what your initial dose should be if your first dose of the day is taken in the evening — say, after work and/or dinner — but still well before bedtime. This dose is a little higher than the daytime dose because you can afford to suffer some grogginess in the evening; most people are more willing to accept a slightly greater depressant effect in exchange for greater relief of symptoms.
Pre-bed Dose: This is what your dose should be if you’re only taking CBD before bed. It’s much higher than the prior two doses, both because a higher dose is needed to induce sleep and because you want a high enough dose to ensure that it won’t wear off in the middle of the night.
Re-Dose: This is how much you should take after the effects of the initial dose wear off—or if it isn’t effective to begin with. When your symptoms re-occur, take this much and wait 5 minutes if vaping, 15 minutes if using an oral spray, or 1 hour if using ingestible CBD. After that much time has passed, reassess your symptoms, and if they’re still present, take a second re-dose.
The reason the re-dose is so low is because when the effects of CBD wear off, the actual amount of CBD in your system won’t have gone down all that much — remember, the half-life is 18 to 32 hours, so after 4 hours, your blood levels will only have declined by 10 to 20 percent.
Gradually Titrate Your Dose Up or Down
After a few days of using CBD, it’s time to assess how well it’s working for you.
If your initial dose is always effective, you may not need to take quite so much. Reduce your initial dose by 25 percent and see if that still works for you.
If you find that your initial dose frequently isn’t enough to do the job, raise it by about 25 percent instead. Try that dosage for at least a few days before you consider raising it again.
Whatever dosage you end up at, adjust the re-dose accordingly so that it’s equal to about 25 percent of the daytime initial dose.
Over time, you may find that your tolerance for CBD builds up.
How to Manage the Side Effects of CBD
CBD has many potential side effects, most of which are mild and short-lived. Nonetheless, they can be unpleasant, and users will want to do whatever possible to minimize them.
The golden rule here is to use the lowest dose you possibly can while still experiencing relief of symptoms. Side effects scale with the dosage taken—often more so than the main or intended effects of CBD—so you’ll typically get a better benefit-to-side-effect ratio by using the minimum effective dose.
CBD usually reduces anxiety, but a few rare people can suffer a paradoxical increase in anxiety from it. The ratio of CBD to THC may be relevant here; try reducing the amount of THC in whatever blend you’re using or, if there is none, try adding a little bit of THC. If that doesn’t work, you may need to look for other solutions to reduce your anxiety, such as meditation or avoiding stimulants.
Changes in Appetite
Appetite can sometimes go up or down on CBD. Again, this may have to do with the CBD-to-THC ratio. THC usually raises appetite, while CBD usually has no effect but can occasionally lower it, so you could try playing around with the ratio. The other potential solution here is to only take CBD shortly after meals so that it will have little effect on your eating habits.
Changes in Mood
CBD usually has either little effect or a mildly relaxing effect on mood. If you experience more profound effects, then again, you should try adjusting the CBD-to-THC ratio. You may also need to cut out something else you’re mixing it with, like caffeine or alcohol. If none of that works, you may simply need to decrease your dosage.
CBD can cause diarrhea, but this side effect is due to difficulty digesting it rather than the effects of the drug after it reaches your bloodstream. In other words, only ingestible forms of CBD cause diarrhea, so you can avoid this by vaping or using an oral spray.
This is another side effect that is often caused by THC rather than CBD. That said, dizziness can also sometimes be caused by dehydration or low blood sugar, so you may be able to ameliorate it by having a small meal or snack before using CBD and drinking water during and following CBD intake. If that doesn’t work, you should decrease your dosage; unless you’re only taking CBD before bed, this is one of the more dangerous side effects due to the potential for accidents.
For many people, drowsiness is actually one of the desired effects of CBD, but it can be undesirable and sometimes even dangerous during the day. Drowsiness can usually be countered by consuming caffeine or not taking CBD on an empty stomach.
This is a rare side effect, but a few people do get nauseous from CBD. This can sometimes be prevented by adjusting the ratio of CBD to THC—usually by increasing the THC level—or sometimes by changing the timing of your dosage relative to eating. Taking CBD either on an empty stomach or after completely stuffing yourself can also sometimes cause nausea, but this can sometimes be prevented by taking CBD after a small meal.
There is now substantial evidence that cannabis can impair fetal brain development; however, it’s unclear whether CBD per se is dangerous, as studies looking at specific chemicals have only implicated THC in birth defects. Pregnant women should not consume CBD without consulting a doctor, and if they do, they should consume pure CBD, without THC.
Two other strategies for minimizing side effects bear mentioning.
First, it behooves you to occasionally take tolerance breaks from CBD. A week or two off from CBD every two to three months can go a long way toward preventing the need to gradually increase your dosage. By keeping dosages low, you can also keep side effects low.
Second, it may be desirable to combine low doses of CBD with a low dose of another medicine that has synergistic effects. Remember the one study showing synergistic effects of combining low-dose CBD and Prozac; similarly, people using CBD for pain management may wish to try combining a low dose of CBD with a low dose of ibuprofen or another over-the-counter painkiller. People using CBD for sleep induction might see better results with fewer side effects by combining it with magnesium or melatonin.