• Heavy-metal contamination in plant-based stimulants: participants note that tea grown in China often contains elevated heavy-metal levels, while Japanese-grown tea appears safer according to cited papers; origin of coffee beans is likewise assumed to affect metal load.  
• Trade-off between purified caffeine and whole-plant benefits: isolated caffeine (gum, pills, powder) is viewed as easier to assay for contaminants but lacks the polyphenols and sensory experience of brewed tea or coffee; some question whether polyphenols are net beneficial given possible advanced-glycation end-products (AGEs) and oxidized lipids from roasted beans.  
• Cost-effective, high-dose caffeine experimentation: one member reports a daily regimen of 100 mg sublingual/buccal/oral plus 50 mg intranasal twice daily, totaling 0.0033 € per 100 mg dose, and describes ad-hoc inhalation of loose caffeine powder for rapid onset.  
• Safety concerns with intranasal caffeine: community warns of potential mucosal damage, olfactory impairment, and immune effects from chronic alkaline powder exposure; alternatives such as vaping caffeine or using ammonia inhalants are briefly discussed.  
• Underlying causes of lethargy: participants debate whether stimulant use masks deeper issues; one member achieved sustained “flow state” after correcting hormone levels, suggesting differential diagnosis rather than caffeine as the primary fix.  
• Link shared: Nature Physics paper “Simulation of asteroid deflection with a megajoule-class X-ray pulse” (https://www.nature.com/articles/s41567-024-02633-7) posted as relevant high-energy research.