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How long does fastin stay in your system?

Responses (1)

suzanne66 20 Nov 2011

Are you wanting to know because of a drug test?

Fastin (phentermine) has a half life of approximately 25 hours and it takes around 5.5 half life's for a medicine to be eliminated.
Therefore Fastin will be in your system for approximately 137.5 hours (5.5 x 25) i.e.5.7 days (or 6 days) after your last dose.
Other factors to consider include your age, health, weight, sex, metabolism rate etc.

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