In some cases the life insurance carrier may test hair follicles, but that doesn't happen often.
The length of time a drug stays in your system and can be detected by routine testing varies by person, and the type and amount of drugs you use, as well as, how often you use the drugs.
It is very important that you are truthful and answer the questions honestly when you complete your application for life insurance coverage.
If you lie on the application, and then you die as a result of a health issue you did not advise the insurer about on the application, the claim to pay the death benefit on your life insurance policy may be denied if it was determined to be a material misrepresentation which might have resulted in the life insurance declining your application for life insurance coverage.
In addition, there are some life insurance companies that do not require any health exams, blood or urine testing.
Here's how you can learn more about life insurance drug tests and how they work.