Can protein powder go off?

January 28, 2006 5:45 PM

A while ago I bought some protein powder; work and study conspired against me and it never got used. The best before date is February. My question is will the expiry of the best before date make it any less effective? Is it possible for it to go off?
posted by Rc to Sports, Hobbies, & Recreation (7 answers total)

Does it expire this february or last? What I believe will happen eventually is that the proteins in the powder will become denatured and pretty useless.
posted by frankie_stubbs at 7:21 PM on January 28, 2006

Best answer: I would go ahead and use it, as long as it doesn't taste funky. I doubt that the proteins in the powder would denature significantly without exposure to high temperatures or pH extremes, but even if they did, their effectiveness would not be compromised. Denaturation is simply a loss of three-dimensional structure, and when you digest protein your body breaks it down into its component amino acids anyway. You need amino acids, but their particular spatial arrangement is not all that important. So as long as the powder has been protected from light (which can break down amino acids over time), I say go for it.
posted by purplemonkie at 8:03 PM on January 28, 2006

Response by poster: The best before is this coming February. Being a best before rather than an expiry date should mean that it will still be effective for a while afterwards? How long though? There is quite a lot left!
posted by Rc at 8:04 PM on January 28, 2006

Best answer: Proteins in lyophilized (freeze-dried) form are pretty stable for a couple of years. After that, they start to degrade, but it is an incremental process. I'd continue to use it.*

*IANAD, but I work extensively with therapeutic proteins.
posted by kamikazegopher at 9:20 PM on January 28, 2006

Best Before means it will be fine for quite some time after that date, probably at least half as long again as the time between manufacture and Best Before. However if it's Due By then throw it out on that date.
posted by polyglot at 12:57 AM on January 29, 2006

"Best Before" in my experience refers more to taste than to efficacy or safety. It'll be fine, but might taste stale.
posted by muddylemon at 1:15 AM on January 29, 2006

Response by poster: Cheers everyone.
posted by Rc at 1:29 AM on January 29, 2006