I take a daily multivitamin and a calcium tablet. I still have about 200 of each and noticed they have an experation date on the bottle of April 2009. The asprins have a exp date of October 2008. I'm sure they are still ok but how much effectiveness is lost after the exp date is reached?

Safest would be to replace the medication when the expiry date is reached.

Some medications may have a shelf life that could extend up to 2 years beyond that but no manufacturer would be able to guarantee efficacy any time after expiry.

This depends very much on how and where the medication was stored during the time from manufacture to expiry.

All medications, unless indicated otherwise specifically, are "designed" to keep at an ambient temp of no more than 25C and low humidity. Not at all conditions prevalent in Thailand.

These should not be too expensive to replace; best to do so. Dispose of these meds in a manner that will not make it easily accessible to kids or animals when disposed. Best to give it to a pharmacy or hospital to dispose of.

The conditions the drugs are stored under obviously can have a dramatic effect on how long they retain their efficacy. Expiration dates on drugs are set up by companies to comply with certain hypothetical criteria and storage conditions so depending on how one stores them, the date of full efficacy can be either shorter or much longer than the date stamped. I recently saw a test report done on the efficacy of drugs past their expiration date and the tests usually found that the drugs stored under ideal conditions were good long past their expiration date. Personally when I have large quantities of vitamins or drugs that I may not use for some time, I break them in smaller quantities and store them in vacuum sealed bags (I have a vacuum sealer machine) and just open a bag when I need them. I keep the vacuum sealed bags in a refrigerated environment so their shelf life is most likely much longer than the date stamped on it.

These should not be too expensive to replace; best to do so. Dispose of these meds in a manner that will not make it easily accessible to kids or animals when disposed. Best to give it to a pharmacy or hospital to dispose of.

Read 're-sell'