Scicurious, a blogger at Neurotopia with a PhD in physiology, writes,
The molecule is caffeine, and the tattoo itself was designed by artist Glendon Mellow of The Flying Trilobite. I got it to celebrate my PhD.
Why caffeine, you ask?
1) I had a friend once tell me that my friendship was like a hot cup of coffee. Warm, vivacious, stimulating, and comforting. It was one of the best compliments I ever received.
2) I have spent the last six years of my life studying drugs in various forms. Caffeine always spoke to me as a stimulant, because it is so different from other traditional drugs classified as stimulants. I've always been a little different myself.
3) I also spent the past six years studying various neurotransmitters. I will spend more years studying different neurotransmitters. Which ones I study and why will change over time, but caffeine will be with me through all of it. :)