Shelf life of Advantage II?

[momto3cats]

Does anyone know how long Advantage II remains effective while still in the sealed tubes? I have some I bought in May 2014, and another package I bought in April 2011 (thank goodness I keep all the emails from these orders or I would have no idea). I can't find an expiration date on any of the packaging, or any info on the shelf life. Just wondering if I can still use either of the ones I have.

 

[red top rescue]

Advantage remains effective for a really long time.  When it does change, it just loses its effectiveness slowly over time. Both of the batches you purchased should still be very effective because Advantage II was first released in March 2011 so any Advantage II you have is no older than that.   I used some plain Advantage (from a friend who no longer needed it and forgot she had it) and that was at least 4 years old and it worked just fine too.  However, when a vet we knew passed on and our shelter received many tubes of plain Advantage, undated, we knew these were really old because they still said "only available from licensed veterinarians" and Advantage has been available over the counter for many years, and the packaging was different than any we had seen in the past 10 years or so.  We did all try it, and it was not very effective compared to plain Advantage that was 4-5 years old.  They probably don't put a shelf life or expiration date on it because it's very stable and the rate at which it loses its effectiveness is not known.  It never goes bad so it will not hurt your animal in any case. 

 

[momto3cats]

Thanks! I'll just use the older ones first, then,instead of throwing them out.