I have no idea as far as mcg, but if you're looking for 1000iu of hcg, then it will fit in an insulin syringe depending on how you reconstituted.
If you reconstituted 10000 iu with 10ml of liquid, you have about 1000iu per ml (or cc) and it would be 100 units on a syringe.
If you reconstitute with 5ml of liquid, you will need to inject 50 iu on the syringe for a 1000iu dose.