Quick Verdict
Caffeine
Most consumed psychoactive. Adenosine antagonist. Well-established ergogenic aid across nearly all exercise modalities.
Evidence: strong (1300+ studies)
Ashwagandha (KSM-66)
Ayurvedic adaptogen herb, most researched for cortisol reduction, testosterone support, and stress resilience.
Evidence: strong (40+ studies)
Side-by-Side Comparison
| Caffeine | Ashwagandha (KSM-66) | |
|---|---|---|
| Category | performance | adaptogens |
| Evidence Level | strong | strong |
| Studies | 1300+ | 40+ |
| Dosage | 3-6 mg/kg | 300-600 mg |
Stack Compatibility
Caffeine: L-theanine (1:2 ratio caffeine:theanine), Creatine, Tyrosine
Ashwagandha (KSM-66): Magnesium, L-Theanine, Rhodiola Rosea, Zinc
Which Should You Choose?
Both serve different purposes. Choose based on your priority.