Methamphetamine (meth) can stay in your system for varying lengths of time depending on the type of drug test used, dosage, frequency of use, metabolism, and individual health factors. Detection windows by test type:

• Urine: Meth can be detected in urine typically for 1 to 5 days after last use. In heavy or chronic users, detection can extend up to a week or longer

• Blood: Meth is detectable in blood for about 1 to 2 days (24 to 48 hours) after use due to its relatively short half-life

• Saliva: Meth can be found in saliva for approximately 1 to 4 days after last use

• Hair: Hair tests can detect meth use for up to 90 days, providing a long-term history of drug use

• Nails: Meth may be detectable in fingernails for 3 to 6 months after use

• Breastmilk: Meth can remain in breastmilk for up to 72 hours after use

Meth’s half-life:
The half-life of methamphetamine ranges from about 6 to 15 hours, averaging around 10 to 12 hours. This means it takes roughly 10-12 hours for half the drug to be eliminated from the body. Complete elimination generally takes several half-lives, so meth may be cleared from the system in about 2 to 3 days after a single use, but metabolites can be detected longer depending on the test

. Factors influencing detection time:

• Dosage and frequency: Larger or repeated doses extend detection time.
• Metabolism: Faster metabolism clears meth more quickly.
• Age, body fat, health, liver and kidney function: These affect how quickly meth is processed and eliminated.
• Hydration and other individual variables also play a role

In summary, meth can be detected in urine for up to 5 days (longer in heavy users), in blood and saliva for 1-2 days, and in hair for up to 90 days. The drug’s half-life and individual factors influence how long it stays in the system