Are out of date energy gels bad for you? I have some energy gel sachets that are a few months out of date. Do they contain anything that might be dangerous after their best-before date?
I don't think this is problematic. Those gels consist mainly of sugar which is a good preserving agent and are sealed air-tight which means they shoudn't get easily contaminated. So if none of the following conditions are fulfilled, I wouldn't mind using such a gel that is some months over their "best before" date:


The sachet hull is intact, i.e. there are no signs that unwanted air could have gotten in. Look for unwanted openings like deep scratches in the foil, rips, or signs that the package has been havily compressed or worked.
The gels have not been stored in extreme conditions. As long as they were at moderate temperature and not exposed to sunlight most of the time everything should be fine. Also having carried them in your backpack for the weekly ride in summer should not be a problem. I would be somewhat concerned if you had had them with you on a two or three weeks tour in hot climate.


So basically you should be safe and even if you have a spoiled one you should notice that as soon as you taste it – I don't think they will spoil in a way that you cannot notice but will get sick from it. If you are unsure or have to rely on your food on a longer ride do the following: Try one of them at home to see if it's OK and take other food with you on tour as well, so that you can leave the gels alone in case you are not sure about them.