There was at least one post, dating back to 2011, about this topic. I'm not sure there was ever any consensus though.
On TRT for 5 years
Still going strong!
For the last 6 weeks, I've been injecting (IM) 30mg Test Cyp with 250iu HCG in the same syringe. I use a .50cc syringe and the mixture fills it up to the .45 cc mark. This doesn't seem to be a problem. The two fluids stay separate for the most part. I push the T in first and the HCG follows. I have to back off on the plunger force when I get to the HCG since it's less viscous. Shooting it in too fast usually stings a little.
I feel great. I definitely feel the HCG working still (sense of calm, big balls, haha). My labs also indicate that my FT is around 25 and E2 is around 20.
Just thought I'd share my experience with mixing Oil and Water. I follow KSMan's advice for the most part (Thanks KSMan!), but I had to try this to see for myself.
Has anyone else tried this? Experiences?