Marijuana Testing in Houston

Fast THC Screening with Confirmatory Lab Testing

When a marijuana test result needs to hold up to scrutiny, the screening step is only half the answer. At Fastest Labs of SW Houston, every non-negative panel drug test result goes to GC/MS confirmatory testing, a laboratory process that identifies and quantifies specific compounds so the result is defensible, not just fast. We serve individuals, employers, schools, and government agencies across Houston with the same certified process.

Our 5-panel, 10-panel, and 12-panel tests screen for THC (tetrahydrocannabinol) alongside cocaine, amphetamines, opiates, and PCP. Same-day appointments are available, and results typically come back within one to three days.

Ready to schedule marijuana testing in Houston? Call us at (713) 597-7894 or walk in during business hours.

What to Expect at Fastest Labs of SW Houston

Over a decade in drug testing has shaped how we run our facility. Wait times stay under five minutes, collection rooms are among the cleanest you’ll find, and certified collectors handle every specimen with precision. Results are confidential, pricing is accessible, and our private waiting area keeps the experience low-stress. Our team includes bilingual staff, so language isn’t a barrier to getting tested.

We offer urine drug tests, instant drug tests, hair follicle tests, and oral fluid drug tests. On any urine screen that returns a non-negative result, we send the specimen for GC/MS confirmation testing. A standard urine screen uses a 50 ng/mL cutoff for THC; the confirmatory test applies a more sensitive 15 ng/mL cutoff. That two-step process helps make a result meaningful rather than preliminary.

Marijuana’s Legal Status in Texas & What It Means for Testing

Recreational marijuana is currently illegal in Texas under the Health and Safety Code. Limited medical use of low-THC cannabis is permitted through the state’s Compassionate Use Program, but Texas doesn’t issue a physical medical marijuana card. Instead, a registered physician enters the patient’s prescription into the Compassionate Use Registry of Texas.

For safety-sensitive transportation employees, none of that changes the federal picture. Under DOT regulation 49 CFR Part 40, a Medical Review Officer currently can’t verify a positive marijuana result as negative based on a state medical marijuana card or physician recommendation. In April 2026, federal rescheduling moved certain FDA-approved and state-licensed marijuana products to Schedule III, while recreational and other unlicensed marijuana remained Schedule I. That change didn’t alter DOT drug testing requirements. Under current rules, marijuana use remains prohibited for safety-sensitive roles regardless of state-legal status.