California Health & Safety Code §11550 — Under the Influence of a Controlled Substance
Health & Safety Code §11550 punishes anyone who uses, or is under the influence of, a controlled substance without a valid prescription. It is a misdemeanor with a maximum 1-year county jail sentence. Certain enumerated priors trigger a mandatory 90-day minimum jail term. This is a use offense — not a possession offense — and PC §1000 drug pretrial diversion is broadly available.
Reviewed by Daniel S. Rubin, CA Bar 302093 · Los Angeles Criminal Defense Attorney · Under the Influence of a Controlled Substance Cases in All LA County Courts
01 — Quick Facts
HS §11550 — Under the Influence of a Controlled Substance at a Glance
| Fact | Detail |
|---|---|
| Full Name | California Health & Safety Code §11550 — Use of a Controlled Substance |
| Code Type | Health & Safety Code (HS) |
| Classification | Misdemeanor |
| Penalty | Up to 1 year county jail; up to $1,000 fine |
| Prior with Enumerated Priors (§11550(e)) | Mandatory 90-day minimum county jail |
| Firearm at Time of Offense (§11550(e)) | Mandatory 90 days to 1 year jail |
| vs HS §11350 | §11350 is possession — even trace amounts. §11550 is use — being under the influence with no drugs on your person needed |
| PC §1000 Diversion | Broadly available — successful completion dismisses the charge |
| Drug Court | Alternative diversion track for chronic-use cases |
| VC §23152(f) DUI Overlap | Drug-DUI charges frequently filed alongside §11550 |
| Immigration | Not a CIMT — but controlled-substance conviction is a separate ground of deportability under 8 USC §1227(a)(2)(B)(i) |
| If Charged | Call (213) 723-2337 immediately |
01 — What Is HS §11550?
What Is California Code §11550?
HS §11550 Reads:
"A person shall not use, or be under the influence of any controlled substance which is (1) specified in subdivision (b), (c), or (e), or paragraph (1) of subdivision (f) of Section 11054, specified in paragraph (14), (15), (21), (22), or (23) of subdivision (d) of Section 11054, specified in subdivision (b) or (c) of Section 11055, or specified in paragraph (1) or (2) of subdivision (d) or in paragraph (3) of subdivision (e) of Section 11055 of this code, or (2) a narcotic drug classified in Schedule III, IV, or V, except when administered by or under the direction of a person licensed by the state to dispense, prescribe, or administer controlled substances."
— California Health & Safety Code §11550(a)
§11550 punishes the physical state of being under the influence — not possession. Officers develop probable cause via observable symptoms (dilated pupils, elevated pulse, slurred speech, muscle rigidity) and a Drug Recognition Evaluator (DRE) protocol. The offense is completed the moment a covered controlled substance is present in the defendant's system without a valid prescription.
§11550 Use vs. §11350 Possession vs. VC §23152(f) Drug DUI
§11550 — use / under-the-influence, no drugs on person required. §11350 — possession of a controlled substance. VC §23152(f) — driving while under the influence of a drug. Prosecutors regularly stack §11550 and §23152(f) in drug-DUI stops.
02 — Elements of the Crime
Elements the Prosecution Must Prove Under HS §11550
The prosecution must prove each element beyond a reasonable doubt (CALCRIM 2400).
Willful Use of a Controlled Substance
Defendant willfully used a controlled substance.
Under the Influence at Time of Arrest
Defendant was under the influence in a detectable, impairing way at the time of the offense.
The Substance Is a §11550 Covered Substance
The substance is within the enumerated schedules (opioids, cocaine, meth, ketamine, etc.) — not marijuana (which is excluded), not alcohol.
No Valid Prescription
Defendant did not have a lawful prescription authorizing the use.
04 — Penalties
Penalties for HS §11550 Under the Influence of a Controlled Substance in California
§11550 penalty escalates based on priors and companion firearm allegations.
| Charge | Code | Prison Term | Probation | Strike |
|---|---|---|---|---|
| §11550(a) First Offense | HS §11550(a) | Up to 1 year county jail; up to $1,000 fine | Available; §1000 diversion routine | No |
| §11550 with Enumerated Priors | HS §11550(e) | Mandatory 90-day minimum county jail | Above minimum only | No |
| §11550 with Firearm at Time of Offense | HS §11550(e) | Mandatory 90 days to 1 year county jail | Above minimum only | No |
Related Provisions
PC §1000 Drug Pretrial Diversion
PC §1000
Broadly available — successful completion results in dismissal and no conviction. §11550 is on the §1000 eligible list.
VC §23152(f) Drug DUI Companion
VC §23152(f)
Driving while under the influence of a drug — separate 6-month misdemeanor exposure with DL suspension.
PC §1001.36 Mental Health Diversion
PC §1001.36
Available where the defendant has a qualifying mental disorder — broader than §1000.
Additional Consequences Beyond Prison
- PC §1000 pretrial diversion — case dismissed on successful completion (no conviction)
- Drug court alternative — intensive treatment track for chronic-use cases
- Immigration: controlled-substance conviction is a discrete ground of deportability — 8 USC §1227(a)(2)(B)(i) — regardless of CIMT status
- 1-year driver's-license suspension under VC §13202 (discretionary) on any §11550 conviction
- Firearm ban stacks under PC §29800 or §29805 if firearm was present or defendant has qualifying prior
Sentencing References
05 — Defense Strategies
How Rubin Law Defends HS §11550 Under the Influence of a Controlled Substance Charges
§11550 defenses attack impairment, valid prescription, and the DRE protocol.
Valid Prescription
Prescription for the substance defeats §11550 — even if defendant exceeded prescribed dose (People v. Kimble).
Prescription
DRE / Symptom Challenge
The 12-step Drug Recognition Evaluator protocol is heavily attackable — pupil size measurement errors, cross-reactive medical conditions (diabetes, migraine, allergies) mimic impairment.
DRE
Not a Covered Substance
§11550 covers specific enumerated schedules. Marijuana is expressly excluded. Certain research chemicals fall outside the statute.
Schedule
Involuntary Intoxication
Drink-spiking, medication interaction, and secondhand exposure negate willful use.
Involuntary
PC §1000 Diversion
Successful completion dismisses the charge and results in no conviction. §11550 is on the §1000 eligible list.
Diversion
Constitutional Sources
07 — Court Process
How HS §11550 Under the Influence of a Controlled Substance Cases Move Through Los Angeles Courts
§11550 cases are DRE-driven and turn on the impairment evidence.
- 1
Step 1 — Traffic Stop / Encounter
Officer observes objective signs — dilated pupils, elevated pulse, muscle rigidity.
- 2
Step 2 — DRE Evaluation
Certified Drug Recognition Evaluator conducts 12-step protocol at the station.
- 3
Step 3 — Chemical Test
Blood or urine test — confirms presence of covered controlled substance.
- 4
Step 4 — Filing Decision
City Attorney files misdemeanor complaint; often stacks §11550 with §11350 possession and/or VC §23152(f) drug-DUI.
- 5
Step 5 — Arraignment / §1000 Motion
PC §1000 diversion motion filed at first appearance.
- 6
Step 6 — Motion Practice
PC §1538.5 suppression of the DRE examination; challenge to blood-draw warrant.
- 7
Step 7 — Trial or Plea
DRE cross-examination central; medical-mimic evidence introduced. Vast majority resolve via §1000 diversion.
- 8
Step 8 — Sentencing / Completion
Drug counseling, urine testing, and treatment programs — completion results in dismissal.
Los Angeles Courts That Handle HS §11550 Under the Influence of a Controlled Substance Cases
§11550 is heard on the misdemeanor drug-crimes calendar.
Reviewed by Your Attorney
Daniel S. Rubin — Los Angeles Under the Influence of a Controlled Substance Defense Attorney
Daniel S. Rubin has defended clients charged with under the influence of a controlled substance and related offenses in Los Angeles County courts — including Clara Shortridge Foltz, Van Nuys, Compton, and Pomona. He understands that these cases are won in the details: the suppression hearing that eliminates key evidence, the preliminary hearing cross-examination that exposes a weak witness, the penalty phase argument that keeps a client out of the worst outcome.
This page was written and reviewed by Daniel A. Rubin, Los Angeles criminal defense attorney, CA State Bar 302093, with 10+ years of experience defending clients charged under HS §11550 in Los Angeles County. Last reviewed: July 2026.
CA Bar 302093 | Whittier Law School | Rising Star — Super Lawyers 2019–2023 | Under the Influence of a Controlled Substance Cases Throughout LA County
See our full Under the Influence of a Controlled Substance defense practice
09 — FAQs
HS §11550 Under the Influence of a Controlled Substance Questions — Los Angeles
What is the difference between HS §11550 and HS §11350?
§11550 is a use offense — being under the influence — with no drugs on your person required. §11350 is a possession offense. Prosecutors frequently stack both counts.
Is marijuana covered by §11550?
No. §11550 expressly excludes marijuana (cannabis). Marijuana-related driving impairment is prosecuted under VC §23152(f) (drug DUI), not §11550.
Can I be dismissed through diversion?
Yes. §11550 is on the PC §1000 pretrial diversion eligible list. Successful completion results in dismissal and no conviction. PC §1001.95 (judicial diversion) is a backup track.
Does a valid prescription defeat §11550?
Yes. A valid prescription for the substance is a complete defense — even if defendant took more than prescribed (People v. Kimble). Bring prescription records to your attorney immediately.
Available 24/7 — Free Consultation
Charged With HS §11550 in Los Angeles?
§11550 cases are DRE-driven and diversion-eligible. Rubin Law, P.C. wins §11550 cases at the DRE cross-examination and through §1000 diversion. Call (213) 723-2337.