The worst taste after pinning, I've had with injectable dbol used as preworkout. Pure chemical taste in my mouth for about one hour and the smell of this oil was the same, the whole room was stinking! Have pinned it three times and thrashed the rest of this crap. It's normal that you could have another taste after pinning, but if you got oils with this extremely bad taste i would get some others and stop using this shit.

Don’t think it’s Deca as had similar experience with other compounds too

you hit arteries veins capillary's etc.
most likely capillary bed, which are everywhere. You hit em every single time.

every layer you go through you hit them.
The more ml's you are putting in the greater the chance of a higher volume making it to the mouth.
2 ways it happens... 1) pumonary embolism, and 2, simply entering bloodstream where it is transported to every part of the body including mouth. The less diluted the stronger the taste of whichever chemical it is you taste. Hell, if your gums bleed easy when brushing teeth, you can get a significant taste from IM and IV injections. But its simply most likely entering the tonge via blood flow.

As Mak said it’s the solvents. I’ve ran a 300mg/ml deca before and I got the worst ‘Tren cough’ imaginable. No matter how small of an amount I pinned it hit me like a ton of bricks.

It's not that uncommon man.
You can get - metal, poison, rust, perfume, grass, kinda like sweat etc. taste in mouth after injecting NPP, Deca.
I have seen this brought up on other formus.
I thought I am getting wierd taste in mouth after tren, but light one, kinda rusty metal one. After about 2mins to five after injecting.
Mybe someone here knows more about this.

It is the solvents not the deca you are tasting.

If it has guacoil in the oil youll taste it.