Yes and no. Legality is a complex topic because it depends on where your CBD product comes from. CBD is legal at the federal level only if it’s derived from U.S.-grown hemp that has a license and permit under the Farm Bill; if yours is flown in from overseas or is derived from the marijuana plant, it’s technically not federally legal. (A cannabis plant is either hemp or marijuana, depending on how much THC is in it. Hemp has 0.3 percent THC or less by weight when harvested, while marijuana has more than 0.3 percent THC by weight and is still federally illegal.)

Making it more complicated: Some states have restricted CBD sales, so even if your product was derived from federally legal hemp, its legality where you live does vary by state. There’s a chance that you might run into law enforcement who’s not up-to-date on the bill and arrest you for possessing it—but it’s unlikely.

There are tons of CBD products on the market, from lotions you rub on to capsules you swallow and tinctures you drop under your tongue. All these are made similarly: By extracting CBD, or cannabidiol, from a cannabis plant and then diluting it with a carrier, such as coconut oil. The way you choose to use it is totally a matter of preference and might require some experimentation.

You can’t OD on CBD, but the dosage is personal- more does not necessarily mean better. When figuring out your optimal dose, add a bit more every three days or so and see how you respond. If you get to a point where you don’t feel any extra benefit (or feel worse), you’ve gone too far; dial it back a bit the next day.

Tinctures: In some products, 10mg is a few drops; in others, it’s a whole milliliter. Put the oil under your tongue and hold it there (no swallowing!) until it absorbs.

Orally (e.g., popping a pill), you’re going to need more, because you lose a bit of the active ingredients to something called first-pass-metabolism by the liver. A pill with 15 or 20 mg of CBD might be comparable to 10 mg of a tincture. Also, keep in mind that oral ingestion results in a delayed onset, so wait an hour or two before adding any more, especially if there’s THC in there.

Topicals: which are a great option for eczema, burns, or other skin conditions, dosage depends on the concentration of the product, but generally just apply a small amount, as needed. Topicals also can help with headaches or migraines if you apply them at the onset.

Whenever you’re starting out with a new product, the best time to try it is right before bed—just in case it makes you drowsy. Even if it doesn’t, you’re pretty much guaranteed a good night’s sleep.

Yes, and it may be your best bet if you’re hoping to achieve quick pain relief. Of all the options for taking CBD, vaping has the most rapid onset; you’ll feel its effects within minutes. Some people use CBD daily for the prevention of a migraine, but if they feel one coming on, vaping might be a good way to get an almost immediate CBD delivery to abort a migraine quickly.

One caveat: Most vaporizers use either propylene glycol or vegetable glycerin (PG or VG). Those are added ingredients used as carrier oils, and unfortunately, we don’t know yet whether they’re safe to vaporize. If immediate pain relief isn’t a priority, another option, like a tincture, cream, or capsule (which take longer to set in), might be the safer way to go.

The perfect dose varies from person to person. It also depends on a few things—the first being whether you’re using an isolate or full-spectrum product. Isolate products are pure CBD while full-spectrum products contain multiple cannabinoids and oils, vitamins, and more natural compounds. With full-spectrum products, you need a lower dose—and that might prevent drug interactions and will be easier on your liver.

Your ideal dosage also varies based on how you’re taking it—you’ll need less from a tincture than a capsule, for instance, because tinctures have greater bioavailability (meaning more gets into your bloodstream and causes an effect).

But as a general rule? Start low and go slow, more isn’t always better. Start with 10 mg worth of active ingredients a couple of hours before bed. Each day, you can increase the amount slightly and take note of how you feel; dial it back when you don’t feel any extra benefit (or even feel a little worse) from additional milligrams. The sweet spot will likely be between 10 and 40 mg a day.

Unlike smoking a joint, using CBD won’t leave you with a giggling fit or the munchies. It can, however, make you sleepy. The most common side effect is drowsiness, so don’t take it for the first time and get behind the wheel or head into a big presentation. Wait to see how your body responds, just in case. In some cases, CBD can exacerbate heartburn or lead to mild allergic reactions, such as hives (though this is likely a reaction to the carrier oil added to the CBD). Using CBD can also cause diarrhea or a change in appetite or weight.

All that being said, if you’re taking CBD for a condition like anxiety or epilepsy, the potential drawbacks are generally milder or less of a nuisance than the side effects you might expect from traditional medical treatments.

The real concern when it comes to side effects is whether or not the CBD in your medicine cabinet is legitimate. You first need to find out if it’s even real CBD, as synthetic can be dangerous. Then look into how the plants are grown, how the product is manufactured, and what quality assurance tests the brand conducts to ensure safety and the elimination of pesticides, chemicals, microbes, and molds. It’s an unregulated industry, and there’s a lot of great branding and marketing out there, but unfortunately, transparency is rare and not knowing what you’re getting is common. Usually, that risk just means wasting your money, but it could be harmful, if there are dangerous chemicals in there, for example. Contact the company with these questions; any reputable brand will be willing to provide customers with all these details.

As a general rule, CBD should be out of your system in less than a week after you stop using it. But it varies from person to person, and the longer and more frequently you’ve taken it, the longer it’ll take to get out of your body. Here’s why: it’s lipophilic, meaning it dissolves in fats and compounds in your body over time. That’s a good thing when you’re looking to prevent pain or alleviate anxiety, as the compounded levels boost the health benefits. But yes, it will make the CBD take longer to leave your system if you decide to stop using it.

Not only can you, but for the best effects, in most cases, you actually should take CBD on a daily basis. You can’t overdose on CBD, and it’s lipophilic (or fat-soluble), which means it compounds in your body over time, adding to potential health benefits.

Still, less is more, because CBD is metabolized through the same pathway in your liver as many common prescriptions and OTC meds. For that reason, sticking with full-spectrum products (which contain multiple cannabinoids and oils, vitamins, and more natural compounds) as opposed to isolate products, which are pure CBD is recommended. With full-spectrum products, you need a lower dose—and that might prevent drug interactions. (Drug interactions are pretty uncommon, especially at low doses, but can occur with some commonly used ones, such as SSRIs and blood thinners.) Plus, with smaller doses, you’ll avoid stressing out your liver.

There’s some evidence out there that CBD can adversely affect a damaged liver, and there’s other evidence that shows it can be helpful—it seems to depend on the underlying cause of liver damage. If you already have liver issues, talk with your doc, keep a close eye on your dosage, and be sure to monitor hepatic enzymes every three months.

The bad news: Your body metabolizes CBD through a pathway in your liver known as CYP 450, where enzymes break up potentially harmful compounds—and it’s the same pathway in your liver that metabolizes most common prescriptions and over-the-counter medicines.

The good news: You likely aren’t taking a high enough dose of CBD that it will cause an adverse reaction with any other medications you might be taking. To lower your risk, even more, make sure the CBD you’re using is a full-spectrum product rather than an isolate, so you can get the same benefits at a lower dose. Also, opt for a product that's not oral, as capsules involve a first pass through the liver that tinctures and other products don’t.

Talk with your doctor before combining CBD with any drugs you’re already on, especially if you take blood thinners or antidepressants.

How fast your CBD takes effect totally depends on what form you’re using. Need to kick an acute ache, like a migraine, ASAP? Try vaping or sublingual strips. Vaporizing CBD has the fastest delivery—you should feel the effects set in within mere minutes.

If your needs are not quite so urgent, you might opt for a tincture; you’ll still feel the effects soon—usually within 20 minutes to an hour—since the liquid quickly absorbs into your bloodstream after you drop it under your tongue. This usage allows the CBD to bypass the first pass through your liver that capsules require before you feel their effects.

If you use CBD daily for preventative reasons and don’t need quick relief, an oral product might be for you. They take the longest to onset (at least an hour or two), but they're a good option for people who don’t like the taste of tinctures and want the convenience of capsules.