Yep. Fill the syringe and freeze them. I make sure mine are needles up and a very small amount of air since water slightly expands when it freezes. HCG breaks down so thats why it has a liquid lifespan. Freezing can damage the HCG but once frozen its frozen. Basically time is now paused compared to liquid in a fridge.
I've injected HCG straight out the fresh mix and also needles that were almost a year old. I have missed/forgot/buried the freezer that holds my HCG and went months without it. Pull a syringe, let it thaw 30-45 minutes and itll make my ball ache some just like a fresh vial.
Also we talk in "iu" about HCG. The liquid can be different amounts. If you add 1/2 the water to your HCG powder it will be twice at potent per mL. Is it 100iu? 500iu? 1k iu? All of them could be in .45mL.