It's not recommended to take phentermine while breastfeeding. Phentermine, which is part of the amphetamine family and often used for weight loss, can pass into your breast milk and potentially impact your baby.
Moreover, it's important to know that phentermine has a long half-life of about 20 hours 1 , which means it takes about 20 hours for your body to clear just half of the dose. So, even 12 hours after taking it, there can still be a significant amount of the drug in your system.
While there isn't extensive research 2 on phentermine and breastfeeding, we know that weight loss drugs can sometimes lead to issues such as restlessness or sleep disruption in infants.
Given these potential risks, it's always a good idea to consult with your healthcare provider before taking any medication while breastfeeding.
