The brain continues to develop until your mid-20s. Regular and heavy cannabis use before the brain is fully developed can make it harder to do well at school or on the job. It may also be harder to stop using cannabis if you start at a young age.

Don’t use synthetic cannabis like “Spice” or “K2.” Synthetic cannabis is not cannabis: It is made by spraying unregulated chemicals onto any type of shredded plant. These chemicals can be toxic and may result in serious health problems.

Like smoking cigarettes, smoke from cannabis can harm your lungs and make it harder to breathe. To reduce breathing problems consider a vaporizer or edible cannabis instead of smoking. If you do smoke cannabis, avoid deep inhalation and breath-holding as this increases the amount of toxins brought into the lungs.

Wait to feel the effects of cannabis before deciding whether to use more. It takes seconds to minutes to feel the effects of smoking or vaping and 30 minutes to 2 hours to feel the effects of edibles.

If you’ve never used cannabis before or have low-tolerance start with a lower THC product. If using an unfamiliar strain, sample a small amount first and wait to see how you react.

Complications are more likely if you mix drugs. For example, mixing cannabis with alcohol can cause extreme anxiety, nausea, vomiting and fainting. Mixing cannabis with tobacco also increases health harms. Tobacco contains nicotine which is very addictive and can make it harder to cut down or quit.

Have days where you don’t use. More problems are associated with more frequent use.

If sharing, hold joints or devices in a way that you can inhale the smoke or vapor without touching them to your lips. Sharing items that have touched your lips increases the risk of spreading infections including meningitis, flu and other germs.

Cannabis can lead to scary reactions like feeling paranoid or even seeing or hearing things that aren’t there. You are at increased risk if you have a personal or family history of mental health problems such as psychosis.

If you have a bad reaction and feel too high, try to remain calm, stay hydrated, eat something and find a safe place where you feel comfortable.

Cannabis impairs coordination and reaction time. The law does not allow young or novice drivers to have any cannabis or other drugs in their body when driving.

Plan a safe ride if you’re planning on using cannabis: Take public transit, call a sober friend or family member, call a cab or ride share, or stay the night and sleep it off.

Being high can also interfere with your ability to operate other machinery, play sports or ride a bike.

If you’re pregnant be aware that cannabis can harm the fetus or newborn child. Speak with your health care provider if you need medicine to help with nausea. Cannabis can also be passed to the baby in breast milk. Until more is known about the short and long-term effects of cannabis on your baby, it is safest to avoid using cannabis while pregnant and breastfeeding.