how far back can a drug test go

The length of time a drug test can detect substances in the body varies depending on several factors, including:

1. Type of test: There are different types of drug tests, such as urine, blood, saliva, and hair tests. Each type of test has a different detection window.
2. Substance being tested: Different substances have different detection windows. For example, marijuana can be detected for longer periods than cocaine.
3. Frequency and amount of use: The more frequently and heavily a person uses a substance, the longer it can be detected.
4. Individual metabolism: People’s metabolisms can vary, affecting how quickly substances are broken down and eliminated from the body.

Here are some general guidelines for the detection windows of common substances:

Urine Tests

• Marijuana: 1-30 days (depending on frequency and amount of use)
• Cocaine: 2-4 days
• Heroin: 2-4 days
• Methamphetamine: 2-5 days
• Opiates (e.g., codeine, morphine): 2-4 days
• Benzodiazepines (e.g., Xanax, Valium): 2-14 days
• Barbiturates: 2-14 days

Blood Tests

• Marijuana: 2-24 hours
• Cocaine: 2-12 hours
• Heroin: 2-12 hours
• Methamphetamine: 2-24 hours
• Opiates: 2-12 hours
• Benzodiazepines: 2-24 hours
• Barbiturates: 2-24 hours

Saliva Tests

• Marijuana: 1-24 hours
• Cocaine: 1-12 hours
• Heroin: 1-12 hours
• Methamphetamine: 1-24 hours
• Opiates: 1-12 hours
• Benzodiazepines: 1-24 hours
• Barbiturates: 1-24 hours

Hair Tests

• Marijuana: 30-90 days
• Cocaine: 30-90 days
• Heroin: 30-90 days
• Methamphetamine: 30-90 days
• Opiates: 30-90 days
• Benzodiazepines: 30-90 days
• Barbiturates: 30-90 days

Keep in mind that these are general guidelines, and the actual detection window may vary depending on individual factors. It’s also important to note that some substances, such as marijuana, can be detected for longer periods in hair tests because they can accumulate in the hair follicle over time.