On not putting caffeine in the pouch
The supplement aisle defaults to stacking. We took the other path, and we want to explain why — briefly.
The fastest way to make a pre-workout feel like it works is to put caffeine in it. The fastest way to confuse a study is to do the same. If caffeine is in the bottle and the runner runs faster, you cannot tell what did the work.
Katsuo Stamina has one active fraction: bonito peptide. The pouch you order is the same fraction that was studied in the RunplusTrail trial. We did not stack it with stimulants, with beta-alanine, with creatine — because we wanted the effect you feel to be the effect that was measured.
On the grapefruit flavor
Earlier formats of the product — the original Japanese powder packets — were grapefruit-flavored. The capsule format does not need a flavor, so we removed it. One less variable.