I'm not a medicine person (and not a chemist), and the question is mostly theoretical.
I've been thinking about how and why glucose and insulin are used and hwo they work, and I have several questions:
1) Would insulin and glucose react in a container?
From what I've found, they probably shouldn't, but googling is a bit difficult, as most results are about how they work together inside an organism.
2) Can an injection containing both insulin and glucose be used for rapid energy regain in case of physical exhaustion?
Here's what I found so far:
IV Glucose solution is used in china for energy regain, but actually has same effect as drinking sweet water (can be administered if drinking isn't posible though).
There's been some research of use glucose together with insulin for ketotic cows (looks promising, though there were only 12 cows in the experiment). https://www.ncbi.nlm.nih.gov/pubmed/8436669
IV Glucose solutions are usually 5 or 10 percent (at least what I found), and it's mostly used for drips, not injections (sorry if I messed with terms, but I hope you'll understand). As far as I understand that's because injecting too much glucose too fast would be bad (lead to hyperglycemia?). This leads to the next question:
3) If glucose is administered together with insulin, could it be done as an injection and with a higher concentration?
I'm sorry if those are newbie questions and anyone who's been to any kind of medical school knows the answer. I've tried googling in different ways, but couldn't find an answer.
UPD: I am totally NOT going to inject anyone with anything. I'm writing a book and need to know if this could work (after thorough calculations and tests and everything).
UPD 2. Some details of the story:
There are people who can go berserk (and be stronger, faster, etc than usually). The effect is similar an adrenalin rush, but can last for a while and can be induced and cancelled at will (after some training). Physiologically these berserks are no different from regular people (or at least not in a way detectable by modern medicine). My guess for now is that they just somehow can control (at least partially) existing system of stress response.
This berserk state drains energy a lot (yeah, the description would match worldbuilding.se better, that is why I didn't want to post it here) and it's crucial to restore energy as quickly as possible after. My idea is that you can inject 50% (or maybe even more) glucose solution, but I doubt you could drink it, so volume is much less, which is good. Also, if something didn't go exactly as expected, the berserk might pass out on exiting the berserk state, then drinkable treatment is definitely not an option.
For sure, the treatment is complex and contains other things that need restoring. It might be not glucose+insulin, but I thought it might be an interesting solution, as it allows creating substitute treatment given access to any drug store.
Total misunderstanding of human physiology might also be the case. Then I'm sorry to have bothered you.