The legal age is 21. https://www.civilized.life/articles/how-old-to-smoke-weed-in-california/
You can be 18 years old and go to a dispensary for access to cannabis for medical use with a doctor's recommendation letter. 21 years of age and older for recreational use. If you are 18 years old then highly recommended that you apply for the MMIP CARD to show proof that you are an authorize d medical patient. Check this website for both recreational and medical cannabis use www.canorml.org
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