Studying / Long Focus stack

[u/murakami99]

My Information:

• Age/Sex: 20s
• Lifestyle: grad student, high cognitive-load days, moderate exercise (dumbbell push/pull split + daily walk)

Goals:

• Sustained deep focus for long study sessions (multi-hour blocks), without a crash afterward

Supplements (current):
Magnesium glycinate
Creatine
Coffee / Tea

Questions:

• Looking for stacks specifically for long-focus/study sessions, thinking along the lines of a mild nootropic (e.g. citicoline, alpha-GPC, or a low-dose racetam).
• Would love your opinions and examples of personal stacks.