Every formula on this page has been scored against published clinical evidence, third-party lab assays, and ingredient transparency. Slow-release proteins, intra-workout blends, and recovery stacks — ranked, not sponsored.
Each product below is independently scored on a 0–10 evidence scale that weights peer-reviewed research, label accuracy, protein quality (DIAAS), and absence of under-dosed "pixie-dust" ingredients. Prices reflect the standard tub at the time of last review.
Micellar casein delivering ~7-hour amino acid release. Clean macro profile at 24g protein per scoop, low lactose, no proprietary blends.
Micellar + calcium caseinate dual-source blend engineered for overnight recovery. Includes digestive enzymes at clinically meaningful doses.
For dairy-sensitive lifters: a slow-digesting rice + pea protein blend with an amino profile engineered to mirror micellar casein.
Whey-casein matrix designed for peri-workout windows. NSF Certified for Sport, banned-substance tested, and traceable lot-by-lot.
Zinc, magnesium, and B6 paired with a 20g casein serving — formulated for sleep-onset and overnight muscle protein synthesis windows.
Single-ingredient micellar casein from Irish grass-fed herds. Third-party tested for heavy metals, hormones, and label accuracy.
A simplified view of the four criteria that drive our scoring. Full DIAAS, heavy-metal, and label-accuracy reports live in each product's review.
| Product | Protein Source | 3rd Party Tested | Evidence Score | Price / Serving |
|---|---|---|---|---|
| Optimum Nutrition Gold Standard Casein | Micellar | ✓ NSF | 9.2 / 10 | $1.07 |
| MusclePharm Combat Casein | Micellar + Calcium | ✓ Informed Choice | 8.5 / 10 | $0.79 |
| KOS Plant-Based Casein Alt | Rice + Pea Matrix | ✓ USDA Organic | 7.9 / 10 | $1.66 |
| Klean Athlete Isolate + Casein | Whey + Casein Matrix | ✓ NSF Sport | 8.8 / 10 | $2.16 |
| NOW Sports ZMA + Casein | Casein + ZMA Stack | ✓ Informed Sport | 8.1 / 10 | $1.17 |
| Promix Grass-Fed Micellar | Grass-Fed Micellar | ✓ 3rd Party | 9.0 / 10 | $1.14 |
No marketing copy, no sponsored placements. Every product in this index is measured against the same four criteria, weighted equally before the final score is published.
Published peer-reviewed studies on the active protein source, dose response, and anabolic window relevance.
Independent lab assays verifying protein content, BCAAs, heavy metals, and the absence of undeclared ingredients.
Digestible Indispensable Amino Acid Score (DIAAS), leucine threshold, and digestion kinetics from independent research.
Proprietary blends and under-dosed "novel" ingredients are penalized. We reward transparent, full-clinical-dose formulas.
"Three casein brands into the year, I gave up on hype-driven recommendations and started reading the actual study lists. 100 Casein's index is the only product roundup that didn't make me feel like a target demographic. The Promix and Optimum picks have been my nightly staples for six months — measurable sleep quality, cleaner recovery, no gut drama."
Our scoring rubric is published, peer-reviewed, and reproducible. The guides library breaks down protein kinetics, label red flags, and the clinical thresholds we use to flag under-dosed formulas.