California’s DUI law reaches drugs, not just alcohol — including cannabis, prescriptions, and over-the-counter medications (Vehicle Code 23152(f)).
But there is no per-se limit for drugs — and that makes these cases uniquely defensible.
What DUI of Drugs Is
VC 23152(f) makes it unlawful to drive while under the influence of any drug — illegal drugs, but also legal ones like cannabis or a prescribed medication, if they impaired your driving. VC 23152(g) covers a combination of alcohol and drugs.
No 'Per Se' Limit
For alcohol, 0.08% is a bright line. For drugs, there is no equivalent number — no legal threshold of THC or a medication that defines impairment. The prosecution has to prove actual impairment, which is far harder, because a blood test showing a drug’s presence does not show it impaired your driving at that moment.
How These Cases Get Defended
- No actual impairment — the drug’s presence is not impairment, especially with cannabis, which can linger for days.
- Challenging the DRE. Drug-recognition-expert evaluations are subjective and frequently attackable.
- Legal use of a prescription, and lack of warning about driving.
- A bad stop or a flawed blood draw — the same blood-test challenges apply.
Frequently Asked Questions
Can you get a DUI for drugs in California?
Yes. Vehicle Code 23152(f) makes it unlawful to drive under the influence of any drug — illegal drugs, but also legal ones like cannabis or a prescribed medication, if they impaired your driving. A combination of alcohol and drugs is covered by 23152(g).
Is there a legal limit for THC or drugs while driving?
No. Unlike the 0.08% alcohol limit, there is no per-se legal threshold for THC or other drugs. The prosecution must prove actual impairment — and a blood test showing a drug's presence does not show it impaired your driving at that moment.
How do you defend a drugged-driving charge?
By showing no actual impairment (a drug's presence is not impairment, and cannabis can linger for days), challenging the subjective drug-recognition-expert evaluation, showing legal prescription use, and attacking the stop and the blood draw.
GuidesComplete Guide to California Misdemeanors · Glossary · Penalties Reference.
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Ahmed S. Hasan
San Francisco Criminal Defense Attorney · State Bar of California #364992
Ahmed S. Hasan is the founder of ASH Legal, a solo criminal defense practice based in San Francisco. The firm runs on flat-fee representation: one lawyer, one fee, from arraignment through resolution. No hourly billing. No surprise invoices.
Ahmed is a graduate of Emory University School of Law and a member in good standing of the State Bar of California (Bar #364992). His practice focuses on San Francisco misdemeanor defense — DUI, domestic violence, petty theft and shoplifting, drug possession, vandalism, trespassing, and assault and battery — with particular attention to diversion-track outcomes that end in dismissal under PC 1001.95, PC 1001.36 (Mental Health Diversion), PC 1001.80 (Military Diversion), and PC 1001.83 (Parental Caregiver Diversion).
Ahmed previously served as a post-bar clerk with the San Francisco Public Defender's Office, the city's largest indigent-defense practice. He is a member of the Asian Pacific American Bar Association of Silicon Valley.
He represents clients at the San Francisco Hall of Justice (850 Bryant Street) and the Civic Center Courthouse. The ASH Legal office is at 15 Boardman Place, Suite 301, San Francisco, CA 94103.
Free 30-minute consultations are available by phone or Zoom. (510) 545-6515 · ahmed@ashlegal.com