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The Meaning of Drug Toxicology Reports and Tests

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on April 8, 2025.

A toxicology drug test is used to determine if illegal or legal drugs, alcohol or other chemicals or substances are found in urine, blood, saliva, hair or other bodily samples. Toxicology testing is often done to detect abuse of either illicit drugs, alcohol or legal prescription medicines.

In general, there are four types of toxicology (drug) testing:

Workplace Drug Testing

Workplace drug testing is often done when applying for employment, especially for positions that may involve federal or local transportation, airline industries, construction, and other workplaces where safety is of the utmost importance.

Drug testing is common for many U.S. employers to lessen the impact from drug abuse in the workplace. The National Institutes of Drug Abuse (NIDA) reports that drug abuse costs the US economy more than $700 billion annually in increased health care costs, crime, and lost productivity.

Pre-employment workplace drug testing usually requires that the applicant give a urine sample, but may also require saliva, sweat or hair samples prior to employment. In certain jobs, especially those that require a high level of safety, employees may be subject to random drug screening during employment.

Random drug screening may be used in instances of workplace accidents, and if the employer has suspicion that the employee is abusing drugs. During the laboratory evaluation, strict chain-of-custody practices and standards are followed. Initial and confirmatory testing are also instituted.

Workplace drug testing is primarily limited to drugs with the potential for abuse, including some prescription drugs, illicit drugs and alcohol. 

Generally, before performing a pre-employment drug screening test, the workplace must provide written notice of the intent to conduct a drug screening. In addition, the prospective employee must inform you of your rights and provide a written notice of drug screening. In some circumstances and for certain positions, random drug screening may be conducted during employment.

Laws can vary by state and business so always consult with a legal professional for drug testing guidance.

What happens during workplace drug testing?

Employers may use a standard five-panel test of “street drugs” that includes:

Some employers may elect to use a more comprehensive 10-panel drug test that also includes various prescription drugs. Alcohol may also be screened for in some samples. 

A typical 10-panel drug test checks for the following substances:

Learn More: What is a 10-Panel Drug Test and what does it detect? 

How long is a drug detectable in the body?

How long a drug will be detectable in the body after it is taken varies by the substance and dose, how often it is taken, and other factors like kidney or liver function, hydration status, age, active metabolites and other parameters.

Many drugs stay in the system from 2 to 4 days, although chronic use of marijuana can stay in the system for weeks after the last use. Drugs with a long half-life (length of time in the bloodstream), such as the benzodiazepine diazepam, may also remain detectable in the system for a prolonged period.

Drugs can be detected in hair samples up to 90 days, although urine samples are used for most workplace drug screening tests. 

Examples of estimated detection times for common drug substances in urine:

Drugs that can be detected in hair-testing include alcohol, marijuana, cocaine, and amphetamines.

How long does a workplace drug test take?

Results from workplace drug testing are fairly quick and can usually be received in a few days. Negative results are usually received within 24 hours, however, a positive screen will require further testing that may take a few days up to one week.

Do I have to drug test in a state where marijuana is legal?

Recreational marijuana use is now legal in many U.S. states and Washington, D.C. It is also legal for personal medical use in dozens of states and D.C, Puerto Rico and Guam. Rules and laws surrounding the use of marijuana vary by state, and can change over time. Check on your individual state laws and employer for drug testing laws.

In states where marijuana is legal for either recreational or medical use, some companies may stop drug tests for THC detection - or drug testing at all - in jobs that are not safety-sensitive.

It is important that you know the requirements for drug testing at your workplace, even if you live in a state where medical or recreational use is legal. Many employers still treat marijuana use as illegal. An employer may have the right to fire you for being impaired at work, and laws surrounding medical marijuana use and employment vary by state.

Athletic Drug Testing

Athletic drug testing is done to detect banned substances or performance enhancing agents in competitive-level athletes. In the U.S, drug testing may occur in Olympic-level sports, National Collegiate Athletic Association sports (NCAA), and professional sports.

The U.S. Anti-Doping Agency (USADA) is the national anti-doping organization for the Olympic movement in the United States. Within the USADA, testing may occur in competition or out of competition and can occur at any time and at any location. View the World Anti-Doping Code Prohibited List here.

What drugs are athletes tested for in competition?

Examples of drugs that may be tested in athletes include:

As with other drug testing procedures in the U.S., a strict chain-of-command is followed according to defined standards.

For a complete list of banned substances and procedures, consult the USADA website.

Medical / Clinical Drug Testing

Clinical or hospital diagnostic drug testing is conducted to assist in patient medical review, diagnosis and treatment.

How is diagnostic drug testing performed?

Diagnostic drug testing is conducted in hospitals or clinic settings. For instance, a drug class, such as opiates, would be identified in a blood or urine sample, but the specific opiate, such as morphine might not be known. The drugs tested can vary by facility and protocols.

While this might be sufficient for clinical use - for example, to avoid a drug interaction or administer an antidote like naloxone (Narcan), more specific confirmatory tests would be required in cases involving drugs of abuse and to be used as evidence in a court of law. Confirmatory tests would be run if initial screening identified illegal drugs.

Drugs that might be tested for include:

Routine clinical urine or blood chemistry testing (i.e., glucose, electrolytes, creatinine) is often completed in a hospital or clinic setting to assist with diagnosis and treatment, but is not considered drug toxicology testing.

How long does it take get clinical drug testing results?

Clinical laboratory testing is usually completed as quickly as possible to assist in diagnosis and treatment. The testing can often take place in the laboratory of the hospital where the patient presents for treatment. Time is important for a quick diagnosis, especially in overdose or poisoning cases. If drugs of abuse are detected, confirmatory testing may take additional time.

Forensic Toxicology Analysis

Forensic toxicology testing, also known as postmortum toxicology testing, is conducted by a laboratory for medical and legal purposes, which may include death and criminal investigations. The results, which are often considered as evidence, may be subject to use in a court of law.

Forensic toxicology testing may occur after:

Family members may also request an autopsy and toxicology report for a death that does not fall into one of the above categories.

Death investigations are conducted by law enforcement and health officials at the scene to gather any forensic evidence which may include prescription drugs, illicit substances, or over-the-counter medications, and any available information about the prescribers.

What happens during forensic toxicology testing?

Specimens for forensic toxicology analysis are collected during an autopsy that is completed by a medical examiner and pathologist. Standardized procedures are followed for gathering samples at the scene of a death to ensure reliable analysis.

Which drugs are tested for in forensic testing?

Typical drugs and substances that may undergo toxicology screening for a forensic toxicology report include:

Testing samples are sent to a toxicology laboratory with board-certified forensic chemists. Testing procedures may include multiple tests run on various samples involving sophisticated equipment.

Tests may involves methods such as immunoassays, gas chromatography, or gas chromatography / mass spectrometry (GC/MS).

How long does it take get forensic toxicology test results?

While an autopsy is usually completed within a day or two after a death, the final results of the toxicology report may take four to six weeks or longer.

Many factors play into the length of time needed to gather forensic toxicology test results, including:

Additionally, once toxicology results are available, there is an internal review process for quality control, and experts such as board-certified pathologists and toxicologists may be consulted. The final toxicology report may incorporate other information, such as field evidence at the scene of the crime, or the possibility of fatal drug interactions, to determine the cause of death. Finally, before the results of the toxicology test and cause of death can be made public, the family must be notified.

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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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