Delta-9 THC can stay in your system for varying lengths of time depending on factors such as frequency of use, metabolism, body fat, potency of the product, and the type of drug test used. Detection times by test type:

• Urine:
  • Occasional users: detectable for about 1 to 3 days after use.
  • Frequent or heavy users: detectable for 15 to 30 days or more, with some sources noting up to 90 days in extreme cases.
• Blood:
  • Generally detectable for 1 to 2 days after use.
  • For chronic users, it can be detected up to a month.
• Saliva:
  • Detectable for up to 12 to 72 hours after use, with heavy users possibly longer.
• Hair:
  • Detectable for up to 90 days or more, providing the longest detection window.

Additional details:

• THC is stored in fat cells, so individuals with higher body fat percentages may retain THC longer.
• Younger people and those with faster metabolisms tend to clear THC faster.
• The half-life of THC varies, with infrequent users clearing half the THC in about a day, while frequent users may take 5 to 13 days for half to be eliminated.
• The method of consumption affects detection; edibles and concentrates with higher THC potency may prolong detection times.
• Effects of THC last 3-6 hours, but metabolites linger much longer in the body.

Summary:
For most occasional users, delta-9 THC clears from the system within about a week, while chronic or heavy users may test positive for up to 30 days or longer, especially in urine tests. Hair tests can detect use for up to 90 days