Drugs for: Bipolar disorder or schizophrenia
Could cause weight gain: Olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal), clozapine (Clozaril, Fazaclo), lithium
Skinny alternative: Ziprasidone (Geodon)
Our expert says: Drugs for bipolar disorder, especially olanzapine, are notorious for often causing huge weight gains in a short amount of time. Ziprasidone operates differently and is not associated with weight gain.
Drugs for: Hormonal birth control
Could cause weight gain: High–dose progesterone formulations, such as medroxyprogesterone (Provera, Depo-Provera)
Skinny alternative: Low-dose progesterone hormonal birth control formulations
Our expert says: Progestin hormones are so effective at causing weight gain that they’re often prescribed for that purpose in cancer and AIDS patients. One study found that women gained an average of six pounds during the first year on these medications.
Drugs for: Asthma, allergies, inflammation
Could cause weight gain: Oral corticosteroids, including prednisone
Skinny alternative: Inhaled corticosteroids
Our expert says: Taking corticosteroids orally affects the entire body, which is why pills are more likely to cause weight gain than the same medication inhaled straight into the lungs.