Where did all my reta go?

A tiny bit stays inside the needle but not enough to explain this. Needle markings are never exact and neither are people's eyes. Some syringes bought online have scales that are noticeably off. What you're seeing sounds normal. Next time try mixing with 1.1 ml of bac water to give yourself a buffer. Most of these compounds come overfilled by 15-20 percent anyway.

Running it through a filter can also remove some of the product if that's part of your process.

Bac water left behind in the syringe during mixing, peptide staying in the needle after each shot, and pulling past the marked units are all possible contributors. Sometimes the vial looks low until you actually draw and it turns out to be exactly enough after all.

The same thing happened with my first vial. There should have been two doses left, around 0.3 ml, and there was still some liquid after the previous dose. Half a week later it was empty. I think the vial wasn't kept upright and some liquid seeped out through the rubber stopper.

All these explanations are too sensible. Nobody is even mentioning that peptide elves could be sneaking micrograms while you're asleep.

While the other suggestions are possible, you might try adding more bac water on the next mix. That gives more room for small mistakes when the concentration is lower. Drawing only 0.20 ml could be part of the problem. Losing just 0.10 ml across five doses could easily come from tiny errors in mixing and injecting. Try 2 ml of bac water and a 0.40 ml dose.

I saw the same thing at the end of my last vial and then realized I had sprayed some in my face from pushing too much air into the vial.