Can phentermine cause problems in early pregnancy?
This medication is classified as Pregnancy Category X, which means it should never be taken during pregnancy.
Phentermine may cause severe or life-threatening birth defects when used during pregnancy, if used in the first 12 weeks of pregnancy; it is strongly associated with congenital limb-reduction defects (especially limb, and craniofacial reductions).
If you are planning to become pregnant or think you may be pregnant, stop taking phentermine right away and consult your doctor right away.
Remember to always discuss the risks and benefits of any medication with your doctor, particularly if you are or planning to become pregnant.