Cannabis and your body.

The part sold in dispensaries is the dried flower, or "bud," of the female cannabis plant. Look closely and you'll see it's frosted with tiny crystal-like glands called trichomes. That sticky resin is where the plant makes almost everything that matters to you: cannabinoids like THC and CBD, aromatic terpenes, and flavonoids that add color and flavor.

• Flower (bud): the resin-rich part that's harvested, dried and cured.
• Trichomes: the resin glands. They turn from clear to milky to amber as the plant matures, which growers use to time the harvest.
• Pistils: the orange or red "hairs." They're part of the flower's reproductive structure and say more about maturity than potency.
• Sugar leaves and fan leaves: small leaves inside the bud carry some resin and are often used for extracts; big fan leaves carry very little.
• Stems and seeds: no real value for consumption. A lot of seeds usually means the plant was pollinated, which lowers quality.

Indica, sativa, hybrid: useful, but not the whole story

These labels started as descriptions of plant shape (short and bushy vs. tall and airy). Today nearly everything is a hybrid, and the label is a weak predictor of how you'll feel. Two products with the same strain name can test very differently depending on genetics, growing conditions and handling. The lab label, specifically the cannabinoid and terpene numbers, tells you more than the name.

Terpenes are the aromatic oils that give each product its scent, the same family of compounds found in citrus peel, lavender and black pepper. Many people find that aroma is a better guide to what they'll enjoy than THC percentage. The effects below are what people commonly associate with each one; the science on terpenes changing a high (the "entourage effect") is still early.

Your body makes its own cannabis-like messengers, called endocannabinoids (anandamide and 2-AG are the best known). Together with the receptors they bind to, they form the endocannabinoid system, which helps regulate mood, stress, appetite, sleep, pain and memory.

• CB1 receptors sit mostly in the brain and nervous system. THC binds here, which is what produces the high, the munchies and the changes in memory and coordination.
• CB2 receptors are found mostly in immune cells and tissues around the body and are tied to inflammation.

Everyone's system is a little different. Genetics, body chemistry, tolerance, sleep, what you ate and even your mood all change how the same product feels on a given day. Common short-term effects include dry mouth, red eyes (THC widens blood vessels and lowers eye pressure), a faster heartbeat, hunger and short-term memory blips.

• Edibles: if you're new or it's been a while, start with 1–2.5 mg of THC. Many states treat 5 mg or 10 mg as one serving, which is a lot for a beginner.
• Wait two full hours before taking more of an edible. "I don't feel anything yet" is how most bad nights start.
• Inhaling: take one puff, then wait 10–15 minutes before deciding on another.
• Try CBD in the mix. Balanced products (like 1:1 THC:CBD) tend to feel gentler for many people.
• Set and setting matter. Somewhere comfortable, people you trust, water and snacks nearby, nowhere you need to drive.
• Don't mix with alcohol if you're unsure of your limits. Together they hit harder than either alone.

Regular THC use makes your CB1 receptors less responsive, so you need more for the same effect. A tolerance break resets things: even a few days helps, and research suggests receptors largely return to normal after about four weeks without THC.

Daily users who stop may notice irritability, trouble sleeping, vivid dreams, low appetite or restlessness for one to two weeks. Exercise, a steady sleep routine, and breathwork or yoga can make the stretch easier.

How long THC shows up on tests

These are rough ranges; body fat, metabolism, dose and test sensitivity all matter. CBD and hemp products can contain enough THC to fail a test, and "detox" products don't reliably speed things up.

"Greening out" (feeling dizzy, nauseous, anxious, sweaty or panicky) is unpleasant but passes. With edibles it can take several hours.

• Remind yourself it will pass. Cannabis alone doesn't cause a fatal overdose.
• Move somewhere calm and quiet, sit or lie down, and get some fresh air.
• Sip water and eat a light snack.
• Try slow breathing: in for 4, hold for 4, out for 4, hold for 4.
• Some people find CBD takes the edge off, though the evidence is limited.
• Sleep it off if you can, and don't take more to "level out."

• Never drive high. THC slows reaction time and coordination, and effects can last many hours after edibles. Plan a ride.
• Pregnant or breastfeeding: health agencies advise avoiding cannabis.
• Under 21: the developing brain is more sensitive, and it's illegal everywhere.
• Mental health: high-THC products can trigger anxiety or, in people at risk, psychosis. If you or close family have a history of psychosis or bipolar disorder, talk to a doctor first.
• Heart conditions and medications: THC raises heart rate and can interact with blood thinners, sedatives and other drugs. Ask a doctor or pharmacist.
• Cannabinoid hyperemesis syndrome: some long-term heavy users develop cycles of severe vomiting, often eased by hot showers. The fix is stopping use; see a doctor.
• Store it like medicine. Edibles look like candy. Keep everything locked up and away from kids and pets.

• Buy from licensed stores. Licensed products are lab-tested for potency, pesticides, heavy metals, mold and solvents. Use our dispensary Finder to find one.
• Read the label and ask for the lab report (often a QR code), which shows THC, CBD and terpene results.
• Higher THC isn't better quality. Aroma, terpenes, freshness and how the flower was grown and cured matter as much as the number.
• Check the date. Look for a recent harvest or package date. Flower loses terpenes and slowly converts THC to CBN as it ages.
• Skip anything that's fuzzy, musty or smells like hay. Mold is a real risk, especially for your lungs.
• Store it right: an airtight glass jar in a cool, dark place, away from heat and sunlight.

Want to pair cannabis with wellness? Explore 21+ yoga, breathwork and sound sessions in Flow, or browse member events on the events calendar. Check local rules first on our laws page.