I prefer volumetric dosing. I bought food grade propylene glycol and used that. 500mg in 50ml. Due to absence of proper tools, I measured the number of drops of solution equals a ml. Ran about 10 tests that averaged 31-32 drops per ml (low was 30ml and high was an outlier of 40 drops.) Most were between 30 and 34 drops with a median of 32 drops.

I'm thinking 32 drops is spot on for my droppers. I'll sample another to see if they're all equivalent. The 40 drops and the variety around 32 drops I think we're due to measurement error (hard to determine when you hit the meniscus of the next ml. When I measured 30 drops, the next measurement would be 34 drops (I performed the measurements in a the same syringe on top of each other). I verified the 32 drops by doing 2ml through 9ml in a row all with 32 drops .Even if I felt one set of 32 drops was low, it would eventually even out and it came out to exactly 7 sets of 32 drops to measure 7mls.

To make dosing easier I rounded down to 30 drops. I figure this reduction nullifies any weakness in the solution due to the powder sticking to the foil when measuring. Close enough.

So 3 drops is 1/10ml and 1mg of 3-meo-PCP. I also have a diclazepam solution (1mg/ml because it's hard to dissolve and because it makes a drop per day taper really gradual). 3-FPM I eyeball with a scoop (it's forgiving enough with my tolerance. Similarly with Kratom (I use half teaspoons). I might make a 4F-MPH solution next time since over doing it sucks pretty bad (even with my high tolerance). It's just so easy to drop my doses in a water bottle and chug. And it gives me the option to sip on over a couple hours for a more level experience.

Excuse any typos please, on mobile and very tired.