Got CBD questions? We have answers. From what it is, how it works, and where to buy it to what makes it different from THC and hemp seed oil, here is everything you need to know about cannabidiol.

Nearly everyone could use a better night’s sleep, and the members of my household are no exception. So when my roommate recently tried to order CBD gummies off Amazon—and got “hemp oil” gummies instead—we were disappointed to find out that the biggest relaxing component transparently listed in the ingredients was melatonin, a common ingredient that purported CBD manufacturers tend to mix into their finished product.

Of course, you’re not supposed to be able to buy CBD products on Amazon. The website forbids the sale of the product as one of its policies. But that doesn’t mean you can’t buy CBD, or at least products that are definitely subtly marketing themselves as containing that cannabinoid, as The Washington Post discovered last year. The newspaper bought 13 products from Amazon that should have been CBD-free, but the majority contained at least some amount of the substance. One even contained a very small amount of THC. Outside of independent lab testing, there’s few ways to ensure quality control on the myriad hemp-based products available online.

Amazon didn’t tell The Washington Post why it doesn’t allow retailers to sell CBD, but it’s likely because of the compound’s ties to hemp, a plant that was only legalized a few years ago through the 2014 Farm Bill. It’s also likely because CBD has become a high-demand product in recent years, with a number of manufacturers making unproven claims that the cannabinoid can induce calm, relieve pain, and reduce stress. So far, scientific research has validated that CBD can sometimes be used to treat rare forms of epilepsy; the FDA even approved a medication containing CBD in 2018 for the express purpose of treating severe epilepsy. Rampant claims that CBD can be used to treat everything from arthritis to asthma, however, have yet to be proven. Mostly, the cannabinoid’s powers have been backed by an avalanche of anecdotes.

Still, as Houman Danesh, Mount Sinai Hospital’s director of integrated pain management, pointed out to Health Magazine, CBD is perfectly safe to try. More research is needed to know exactly how CBD interacts with the body, but it doesn’t seem to have any known, severe negative effects or risks. So if you’re curious about CBD gummies, tinctures, or edibles, feel free to sample a few. First, though, you’ll want to make sure to avoid the numerous, dubious brands online and in stores that are claiming to contain CBD to latch onto the current craze. To help you on your cannabinoid quest, here are a few basic explanations about the compound, as well as an abbreviated guide to navigating the world of CBD.

What’s CBD? And what’s the difference between it, THC, and hemp oil?

CBD, or cannabidiol, is one of 400 compounds found in the marijuana plant. In fact, in most marijuana strains, it’s the second most common component. Most CBD oil, though, is distilled from hemp plants—a cousin of marijuana. Those plants contain little, if any, THC, making it easier for manufacturers to isolate CBD when processing the plant.

Unlike THC, marijuana’s most famous compound, CBD is not psychoactive. That means it will not get you high or alter your state of mind. A very small percentage of people may experience some changes in their sobriety after taking CBD, but those patients are usually the same ones that experience side effects from Tylenol and other mild drugs, according to Health Magazine. As with any new supplement, people trying CBD for the first time should do so in a comfortable setting and with supervision.

Some people have raised the concern that taking CBD might lower the effectiveness of hormonal birth control, or even cancel it out altogether. However, there’s little scientific evidence at the present for this claim. A 1983 study conducted on rats concluded that CBD seemed to bind more to estrogen receptors than other compounds in the marijuana plant, but no similar studies have been conducted on humans. If you want to try CBD while taking hormonal birth control, there’s no harm in being cautious and using a second form of birth control, or in simply skipping the drug altogether until there’s more concrete proof about its effects on estrogen receptors in humans.

Because most drug tests are testing specifically for THC, taking CBD should not cause someone to fail a drug test. However, as mentioned above, the cannabinoid supplement market is heavily unregulated right now, meaning that consumers could ingest a gummy containing THC inadvertently. If drug testing is a concern for a consumer, it may be better to only buy from vendors who have certified that they only use CBD isolate, or to simply hold off altogether.

Hemp oil, or hempseed oil, is derived from the same cannabis sativa family as most CBD. However, it’s made from hemp seeds, not from the grown plant, and it contains no CBD or THC. Hemp oil has shown some promise as a skincare product, and the seeds contain plenty of healthy fats and may help with heart conditions. But they’re not CBD, and marketers know that that’s what many consumers are looking for. So if you see a bottle of gummies listing hemp seed oil or cannabis sativa seed oil, know that they may be marked up as if they contain actual cannabidiol. Products that do contain genuine CBD will usually list that ingredient as cannabidiol, full-spectrum hemp, or phytocannabinoid-rich, according to Healthline.

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So what does CBD do? And how does it work?

As mentioned above, CBD has so far only been proven to work for some forms of severe epilepsy, like Dravet syndrome and Lennox-Gastaut syndrome. But, according to Harvard University’s Health Blog, it has shown some promise as a pain treatment. A European Journal of Pain study showed that the compound relieved some inflammation and pain for an arthritic animal, but more study is needed before scientists can say definitively that the compound similarly treats pain in humans.

Scientists are still figuring out how CBD works, but so far we know that the process does involve our natural endocannabinoid system, much like THC does. All people produce endogenous cannabinoids, or endocannabinoids, which are molecules produced by the body which function similarly to the cannabinoids found in the marijuana plant. Scientists are still trying to figure out what the endocannabinoid system does, but so far it appears to have influence over a number of factors in a person’s life, including their appetite and ability to digest food, their mood, their ability to sleep, and their immune system. We also all have receptors as part of the endocannabinoid system that allow cannabinoids to be used by the body. When someone uses THC, that compound binds to those receptors. CBD doesn’t appear to bind to the known endocannabinoid receptors like THC does, so scientists are still figuring out how the body utilizes it. Some marijuana advocates have claimed that CBD works better when paired with THC, which is why dispensaries in states where recreational and medical marijuana is legal often sell products that have a small amount of THC added. That claim has also not been scientifically validated, however, so it should be taken with a grain of salt.

Is buying CBD legal?

On the federal level, CBD and other hemp-derived products have been legal since The Farm Bill passed in 2014. That means that it’s up to individual states to regulate how CBD and other hemp products are sold and used. Most states allow CBD to be bought and sold with some stipulations, but some, like Idaho and Iowa, outlaw cannabis in every available form. You can find out what the rules are in your state by checking this guide, or by looking up the state law code.

Because it’s no longer federally prosecutable to own hemp-based products, you should have no trouble traveling with CBD. The Transportation Security Administration (TSA) has even announced that you can fly with it, as long as you’re following existing guidelines for the amount of liquid you can bring onto a plane.

So, if I want to try CBD gummies, tinctures, or edibles, where do I get them?

If you’re in a state that has legalized recreational or medical marijuana, you can likely find CBD products in marijuana dispensaries, or in some dedicated aisles in grocery stores. Some stores are even dedicated specifically to CBD products. When purchasing from a store in person, you should be able to ask for independent certification showing exactly which compounds the product contains. In Washington state, all dispensaries are required to apply a label to products showing that the edibles or gummies in question have been lab tested. That label will list the percentage of CBD and THC available, and will usually include a suggested serving size as well.

If you’re not in a state that has legalized marijuana altogether, you may still be able to buy CBD in stores, with some caveats. First, check the ingredients list to make sure that the store is not passing off hemp oil as CBD. Next, check the label to see if they’re making any outrageous health claims, such as that CBD will cure or prevent chronic conditions. These claims indicate that the brand isn’t operating transparently, and likely isn’t worth the money.

Regardless of whether you’re buying online or in person, you should be able to see some proof that the product was tested by a third-party lab. Additionally, it should list any additional ingredients, like melatonin, and ideally should have information on when it was processed, where, and in what batch. That information could come in handy if a recall occurred, as Health Magazine points out.

If you’re buying your CBD online, you’ll have more luck going through an independent retailer, like Sugar and Kush or Charlotte’s Web, than you will going through a large independent retailer. Always remember that you’re buying a product that isn’t federally regulated, so it’s in your best interest to go with a vendor that provides as much verifiable information as possible.

OK, so I bought some CBD. How much do I take? And how do I take it?

This is a difficult question to answer, because it varies for everyone. The best advice is to start low and slow and see how the CBD products you’ve purchased affect you. Most people experience a relaxing effect from CBD that encourages sleep, so make sure to take them at home, preferably when you have nowhere to be anytime soon.

For beginners, 5 to 10 mg is usually a fantastic starting point for edibles containing either CBD or THC. Unfortunately, there’s no easy way for us to translate that into a certain number of gummies, because companies sell gummies and other CBD edibles in a variety of strengths.

If you’ve bought a gummy or some other edible containing CBD, you should be able to eat it the same way you eat anything else. But if you’ve purchased a tincture, you have a couple of different options for ingesting the oil. The first is to place the oil under your tongue for 15 seconds; with this method, you should be able to feel effects within 10 minutes. The second option is to add a few drops to a drink—preferably a hot one like coffee or tea. Like other edible forms, that method may take at least 30 minutes to kick in, but it may be more preferable if someone finds sublingual dosing to be difficult.

There’s much still to be learned about CBD, but for those suffering from chronic pain, anxiety, insomnia, or other conditions, the currently available studies and copious online anecdotes provide some promise. And for everyone else, it’s always fun to try something new. By learning more about CBD and how it’s made, anyone can try out the trending compound safely, and without having to waste money on potentially useless products.