The Science
Why paraxanthine. Why now.
ANZU is built on paraxanthine — the metabolite your body converts caffeine into anyway. We skipped the conversion step. Here's the research that convinced us, cited honestly: what was studied, how many people, and what the limitations are. None of these are finished-product studies. They are ingredient studies on the exact form — Enfinity® paraxanthine — that's in every tub.
How paraxanthine works
Adenosine is the molecule that makes you feel tired: it builds up through the day, binds to receptors in your brain, and slows things down. Caffeine works by blocking those receptors. So far so good.
The catch is what happens next. Your liver breaks caffeine into three metabolites. Theobromine widens blood vessels and raises heart rate — the racing-heart, jittery feeling. Theophylline stimulates harder and hangs around longer — the anxious edge, and part of why you're still wired at 11pm. Paraxanthine is the third: it does the receptor-blocking that keeps you alert, then clears in hours instead of lingering.
ANZU delivers paraxanthine directly — 300mg of it, without asking your liver to make it from caffeine and without the two metabolites you never wanted. Same clarity. Cleaner exit.
Published research on paraxanthine
The following studies used Enfinity® paraxanthine, the branded form in ANZU. Most were funded or supplied by the ingredient developer — standard for branded ingredients, and worth knowing as you read.
Paraxanthine improves short-term memory and sustained attention.
- Design: Randomized, double-blind, placebo-controlled, crossover
- Participants: 13 healthy adults
- Dose: 200mg paraxanthine (Enfinity®)
- Duration: Single dose, measured over 6 hours
- Significant improvements in short-term memory tasks
- Fewer errors in reasoning tests after 6 hours
- Improved response times in memory retrieval after 2 hours
- Sustained attention and vigilance enhanced at 2 and 4 hours
Small sample size (n=13). Single-dose, not long-term. Results warrant larger trials to confirm.
Yoo C, et al. Nutrients. 2021;13(11):3669.
Paraxanthine outperforms caffeine on cognitive function after intense exercise.
- Design: Randomized, double-blind, crossover
- Participants: Healthy athletes engaging in regular intense activity
- Dose: Paraxanthine vs. caffeine, administered before a 10km run
- Duration: Single session
- Better post-exercise focus and faster reaction times vs. caffeine
- No evidence of tolerance issues from habitual caffeine use
- Consistent cognitive benefits even after intense exertion
Athletic population may not generalize to non-athletes. Single-session design; long-term effects not studied.
Yoo C, et al. 2024.
No adverse effects found in toxicity studies on paraxanthine.
- Design: Series of mutagenicity, genotoxicity, and oral toxicity studies
- Subjects: Laboratory rats (male and female)
- Doses: 75, 150, and 300 mg/kg body weight per day
- No evidence of mutagenicity or genotoxicity
- No mortality or toxic effects in acute or subacute studies
- No adverse effects at the highest dose tested (300mg/kg/day)
Animal model. Animal safety data does not directly translate to human safety conclusions — it establishes a foundation for human research.
Purpura M, et al. 2021.
Research on paraxanthine (Enfinity®), the active ingredient in ANZU. These are ingredient studies, not finished-product studies. Most paraxanthine research has been funded or supplied by the ingredient developer — normal for branded ingredients, and a reason to read the findings as promising rather than settled.
Why branded ingredients matter
Generic powder and branded ingredient can be the same molecule chemically. The difference is documentation: where it was manufactured, how it was tested, and whether the research used the same material in your tub. ANZU uses branded forms throughout — Enfinity® and Cognizin® — because they have their own quality standards, manufacturing documentation, and published research. We pay more per unit for this. We think it's worth saying plainly.
Enfinity® (paraxanthine)
by Ingenious Ingredients
Cognizin® (citicoline)
by Kyowa Hakko
The Formula
Every dose on the label.
| PARAxanthine (Enfinity®) | 300 mg |
| Citicoline (Cognizin®) | 250 mg |
| L-Tyrosine | 500 mg |
| L-Theanine | 150 mg |
| Vitamin B12 | 100 mcg |
What's on the label: ANZU is a dietary supplement. Net wt. 8.9 oz (252g), 30 servings, 8.4g per scoop. White Peach + Yuzu Citrus.