From the artist:  
“That’s…  
That’s science! AND ALSO HIGHLY ILLEGAL AND IMMORAL
 
Explanation: Sodium Thiopental is a fast acting Anesthetic, that makes users feel calm, secure, and most importantly, Compliant. Which Twiggles wants.
 
But it needs to get to the brain to take effect. And since Twilight can’t just syringe Applejack with a shot of drugs, she’s trying to sneak it into apples.
 
BUT ALSO stuff you eat doesn’t just go straight to your brain. In fact, there’s a Blood-Brain Barrier preventing exactly that. So to bypass that shit, Twilight is sneaking the drug through via a Peptide Agent which carries the Sodium Thiopental through the membrane.
 
And Then [Science 88/90]: the peptide agent Science Science Magic…
 
EXPLOSION”
 
 
Commission from Pshyzo’s Patreon. Posted with artist’s permission.
 
Colored version of this.