Yes some don't and some do.
Drug tests do not test for Phentermine but it is known to cause a false positive result for Amphetamines.
Phentermine will show up in blood test.I'm not sure wether as phentermine or amphetamine because both have same chracteristic.but duromine(resinated phentermine) wont do.ill ask the lab but they said so far, duromine wont disturb with blood test if you don't exceed the dose.
I have a couple guys at work, one got called in for a random. The night before, he took a phentermine 37.5 at around ten pm. His test was negative. Now, on our randoms we use a five panel test. Where as the other guy was hurt on the job, also taking phentermine, he tested positive, but he received a ten panel test as opposed to th five. Have also asked a doctor who prescribes phentermine and he said that a five wouldn't pick it up where a larger panel would. Guess I will find out for sure, I was brought up on a random today and I take prescription phentermine.