Recently Expired prep still good?

[miticax]

Had a bottle of prep that expired last month, and I do on demand prep rarely. The bottle was opened 3-4 months ago but stored at least in a dark place (although not necessarily cold)
Is this still good for another on demand play or better just throw it away?

[viking8x6]

It should be fine if it wasn't exposed much to hot or humid conditions (temperature >30C, humidity >80%RH). 

[kspozcum]

So, without any data provided by the drug manufacturers and without knowing the exact medication you are using (there are a few different drug combinations for PrEP), there is no real answer to this.

Typically, the expiration date on a bottle is the drug manufacturers guaranteed and proven efficacy during drug testing. Most medications are mostly effective after said date, but do begin to lose their potency as they go past the date. Each drug is different, as some drugs begin to change their chemical formulations as they age, others losing strength, and even others can become toxic after a while. There is a ton of variables involved in what direction the medication will take, and there are essentially no medical studies in the field of ARV post-expiration usage.

Studies done with vaccines (which generally are much more studied) have sometimes led to an increased shelf life past regular manufacturer recommendations. For example, the COVID mRNA vaccines showed a high level of shelf stability much farther past their normal expiration date, due to the highly controlled storage requirements.

The NIH has done studies that have showed shelf stability up to 15 years on over 100 different drugs, however even they state that its not ideal and the medication should still be removed from use once expiration has been reached. Unless you can guarantee that the medication has been stored in the manufacturers recommended storage conditions, I would personally suggest discontinuing the use and getting a new prescription.

[think before following links] https://pmc.ncbi.nlm.nih.gov/articles/PMC7040264/

[cub84]

See also, this previous thread

 

Edited 16 hours ago by cub84