• THCA becomes THC with heatBasic chemistry

  Fresh flower holds mostly THCA, which doesn't get you high. Heat from smoking, vaping or baking knocks off part of the molecule and turns it into THC. That process is called decarboxylation, which is why edibles are made from heated cannabis.

• CBGA is the mother cannabinoidBasic science

  The plant first makes CBGA. Enzymes then turn it into the acid forms of the main cannabinoids: THCA, CBDA and CBCA. Different plants make different amounts of each, which is why products vary so much.

• THC vs. CBDWell established

  THC is the main compound that makes you feel high. CBD doesn't. Labels list how much of each a product has, and that ratio tells you more than the strain name.

  Source: New Jersey Cannabis Regulatory Commission
• CBN comes from aging THCBasic chemistry

  As THC is exposed to air, light and heat over time, some of it breaks down into CBN. Old flower usually has more CBN and less THC.

• Indica, sativa and hybridSupported by research

  The names come from how plants grow: indica plants are short and bushy with broad leaves, sativa plants are tall with narrow leaves. After decades of crossbreeding, nearly everything sold today is a hybrid.

• The labels don't predict effectsSupported by research

  A study in Nature Plants found indica and sativa labels often don't match a plant's genetics or chemistry, and same-name strains can be very different. Aroma and terpene profile were better clues than the label.

  Source: Wageningen University (Nature Plants study)
• A better way to sort: by chemistryBasic science

  Scientists group cannabis by its main cannabinoids: THC-dominant, balanced THC and CBD, and CBD-dominant. Reading a label's THC and CBD numbers tells you which group a product is in.

Terpenes give most of cannabis's smell and taste, but researchers have found that the funkiest notes come from other compounds entirely.

• Earthy, musky, ripe mangoMyrcene, a terpene
• Citrus, lemon, orange peelLimonene, a terpene
• Pine, fresh forestPinene, a terpene
• Floral, lavenderLinalool, a terpene
• Black pepper, spiceCaryophyllene, a terpene also found in pepper
• Hoppy, woodyHumulene, a terpene also found in hops
• Fresh, herbal, fruity pineTerpinolene, a terpene
• SkunkPrenylthiol, a sulfur compound, the same molecule behind skunked beer
• Garlic, onion funkRelated sulfur compounds, structurally similar to garlic's
• Sharp, pungent cheeseOctanoic and decanoic acids, fatty acids
• Tropical, juicy fruitTropical sulfur compounds such as 3-MHH
• Dank, chemicalIndole

What each aroma comes from is well documented. Whether terpenes change how a high feels is still being studied.

How fast it starts and how long it lasts depend on how you use it.

Use it well

• Start low, go slowHealth agency guidance

  New to it, or trying a new product? Start with a low-strength product in a small amount, and wait the full onset time before having more.

  Source: New Jersey Cannabis Regulatory Commission
• Read the labelHealth agency guidance

  Check the THC and CBD amounts per serving. More THC means a stronger effect, not a better one, and stronger-than-expected products are a common cause of taking too much.

  Source: New Jersey Cannabis Regulatory Commission · Colorado.gov
• Never drive highWell established

  Cannabis slows reactions and distorts time and distance. Driving high is treated like drunk driving. Plan a ride.

  Source: New Jersey Cannabis Regulatory Commission
• Don't mix with alcoholWell established

  Alcohol, and some medicines like antihistamines, greatly increase impairment. On prescriptions? Ask your healthcare provider first.

  Source: New Jersey Cannabis Regulatory Commission
• Lock it upWell established

  Edibles can look like candy, and children who eat them often need an emergency room. Pets can be harmed too. Store everything locked and out of reach.

  Source: Powers Health · New Jersey Cannabis Regulatory Commission
• Some people should skip itHealth agency guidance

  Anyone under 21, pregnant or breastfeeding should avoid cannabis.

  Source: New Jersey Cannabis Regulatory Commission
• If it's too muchHealth agency guidance

  Extreme anxiety, racing heart, confusion or vomiting? Call Poison Control at 1-800-222-1222, free, any time. If severe, call 911 or go to an emergency room.

  Source: Colorado.gov