 [ Symptoms ] i was told my ongoing chest pain is not cardiac related need second opinion [ Disease ] this is a good question to ask we have a lot of data on alli orlistat because it is a lower dose of a prescription medication you can take alli while on synthroid but you want to space the medications by four hours so take your synthroid at 8 a m on an empty stomach and you can then take alli at noon you also want to let your doctors and health care providers know that you are taking alli and include it on your personal medication list