Within the Broken Arrow forums, part of the Gun Forum category; First- I'm not a doctor/pharmacist/pharmacologist/whatever. So don't blame me if you listen to my opinion and consume expired doxy. First- I'm not a doctor/pharmacist/pharmacologist/whatever. So don't blame me if you listen to my opinion and consume expired doxy. Second- I believe that antibiotics are still effective past their expiration date. Now: The long debated issue is that tetracyclines including doxycycline become toxic after its expiration date due to the compounds breaking down and producing a waste. Department of Defense Shelf Life Extension Program. I've read on a few sources that tetracyclines were redesigned so as not to produce this hazardous waste. The FDA regularly tests the DODs expired doxycycline and extends the shelf life. After quite a bit of research I have concluded that doxycycline is safe to take at any time as long as it was stored in a cool and dry environment in its original packaging or pill bottle stuffed with cotton. For doxy specifically it states anywhere from 17-133 month extensions have been granted. In my research I came across an FDA sanctioned pamphlet that addresses using doxycycline to treat anthrax exposure. At the very bottom of the 2nd page it states that if you receive doxycycline that is expired, it's okay the FDA has approved it for use. Now I understand that they are approving THEIR stock of the expired doxycycline, but if it's all stored the same way... A question for pharmacologists: How exactly do doxycycline hyclate tablets break down after the expiration date? I have nearly an entire bottle (was for my cats) that expires this month. All the online drug references say to throw doxycycline out when it reaches the expiration date, but they don't say what happens. The only cite I could find was this one for tetracycline where a Darwin award contestant developed Fanconi syndrome after taking 4g(! ) of tetracycline over a 48hr period -- pills that she had let get wet and then dried out, then kept these deteriorated pills in a cardboard box for a year before using them again! The problem with drugs after there expiration date is that no one actually knows what happens to them. Here it says doxycycline hyclate is normally stable and doesn't break down. Expiration dates are normally set by what's called advanced stability testing, where they simulate how long a drug will last In the lab. My vet tells me that generally, most antibiotics in tablet form are pretty stable. But they can only use that for a maximum of 3 years. It could be safe, or it could do nothing, or it could be toxic. However, it is an antibiotic which shouldn't be used except under a doctor's recommendations, so I would just suggest tossing it.
Aug 5, 2015. In the U. S. a medication's expiration date is like the pharmaceutical company's. Doxycycline 100mg tablets, 2 years, 5 years, 7 years. Throw away any unused doxycycline when it is out of date or when it is no longer needed. Do not take any doxycycline after the expiration date printed on the bottle. 6.