Recent policy changes in a number of states legalizing cannabis for medical and/or recreational use suggest a shift in societal attitudes and perceptions around cannabis. University Health Services takes a harm reduction approach to all substance use, including cannabis. 

Cannabis Harm Reduction

If you are considering using cannabis, here are some tips that you can use to reduce your risk of harm and bad experiences:

  • Avoid cannabis smoke if possible. Cannabis smoke contains tar and toxins. The safest choice is to use a vaporizer.
  • Take shallow puffs, not deep inhalations. About 95% of the THC in the smoke is absorbed in the first few seconds so you don’t need to puff hard or hold your breath.
  • Leave tobacco out of the mix. Tobacco contains many cancer-causing toxins, so it's safer to smoke cannabis by itself.
  • Water bongs are not as safe as joints. Bongs filter out more THC than tars since water tends to absorb THC. This requires you to puff harder, increasing the amount of tar that is inhaled. Plus, pipes and bongs with plastic/rubber give off toxic fumes.
  • Stay away from the steering wheel. Cannabis can impair your motor coordination, judgment, and other skills related to safe driving. It's safest to wait three to four hours after using cannabis before driving.
  • Trust your best judgment and be safe!  

Health Information

Cannabis use has both potential therapeutic benefits and real health risks.

  • Therapeutic effects may be myriad and are experienced differently by different people. We encourage you to consult with a medical provider about your medical symptoms, and various ways to treat them.
  • As with any medication or substance, individual experiences with side effects and outcomes of use will vary depending on a number of factors, including dosage, frequency of use, method of use, genetics, physical and mental health, and personal life history and context.

Policy and Legality 

In November 2016, California voters passed Proposition 64 legalizing recreational use among people over the age of 21. However, because federal law still prohibits the use, distribution, and possession of cannabis, it remains prohibited on all university property and at all university events, except for approved academic research. 

In addition, smoking cannabis or any product on university property is prohibited by UC policy per the University of California – Policy on Smoke and Tobacco Free Environment


If you are concerned about your use or someone else’s use: 

For more information regarding the legality, health effects, and other issues related to marijuana: