Hello, welcome to HCM, and thanks for your question.
If you are referring to marijuana, then you will pass the
drug test. Marijuana remains in the system up to a week after
smoking it. In some cases of chronic frequent daily use, it can last up to several months in the system, as it is absorbed into the fat. But since this is the first time you have smoked in two years, it will be out of your system by now.
There is no need for detox or drinking extra water. This will not affect your
metabolism.
In the future, for continuity of care, I encourage you to contact me at my private link below. After you ask a direct question it would be my pleasure to be your dedicated personal physician on this website. My name is Dr. Sheppe, and I am an American doctor working in New York City at NewYork-Presbyterian Hospital, ranked #1 for Psychiatry in the United States (tinyurl.com/psyrank). For a personalized comprehensive evaluation, treatment recommendations, and individual therapy, ask me at HealthCareMagic at this private link: tinyurl.com/DrSheppeAnswers