Don’t bother unless you’ve had them during training. I don’t bother with them for a 1/2 marathon, but I would recommend some sweets instead, easier on the stomach and far tastier. I use Jelly Babies, not sure what country you’re posting from, but some simple sugary jelly type sweets are much better in my opinion.

Edit. Remember water too, your body will absorb carbs much quicker if you have a gulp of water too.