Quality & Digestibility
Yeast Protein has a PDCAAS of 1.0, based on five batches of amino acid profile analysis and an in vitro digestibility of 84.91 ± 0.52% .
Its protein quality equals whey protein concentrate and is higher than soy protein isolate for adults .
As a complementary protein, Yeast Protein improves digestibility and amino acid absorption in blends .
It also supports gut health—boosting microbial diversity, improving intestinal balance, and increasing short-chain fatty acid production .
Build and Recover, Faster
Yeast Protein is naturally rich in Branched Chain Amino Acids (BCAAs), which help prevent muscle loss and support post-exercise recovery by promoting glucose production .
Tests show BCAA content of ≥20.0%, higher than pea protein isolate and comparable to whey protein concentrate .
Clinical trials show increased lean mass, strength, and endurance in adults 40+ when consumed twice daily at 20 g per dose for 8 weeks, combined with resistance exercise.
At 1 g/kg/day, Yeast Protein also improves muscle size and strength, and helps reverse age-related muscle loss.
Clinically Matched with Whey
Participants: 116 healthy men aged 40+ were enrolled; 79 completed the study.
Intervention: Subjects consumed 40 g of Yeast Protein, whey protein, or placebo (maltodextrin) twice daily for 8 weeks.
Exercise: All participants followed a resistance training program three times per week.
Assessments: Lean mass (DEXA), strength, and endurance were measured at baseline, week 4, and week 8.
Results: Both the Yeast Protein and whey groups showed significant increases in lean trunk and total lean mass.
Yeast Protein is a proven, sustainable alternative to whey for enhancing lean mass, strength, and endurance especially in individuals with low dietary protein intake .
Peer-Reviewed Research
To create the future of nutrition, we started with the facts. We believe any truly innovative product must be backed by transparent, peer-reviewed science. The research presented here forms the evidence-based foundation of Spacemilk, exploring the quality, performance, and safety of our novel yeast protein.
The most important question is: does it work? A high-quality human study found that our yeast protein builds muscle and strength just as effectively as whey protein when combined with exercise. Foundational lab studies explain why: it’s a complete protein with a balanced amino acid profile that is easy for the body to digest and use. Further research shows even more benefits, suggesting yeast protein can help with age-related muscle health, support a healthy gut, and help the body absorb calcium for stronger bones. This body of research is why we are confident that Spacemilk is a trusted, forward-thinking choice for your health.
Journal of Food and Nutrition Research, 2024
Yeast Protein Shown to Rival Whey in Building Muscle and Strength
A double-blind, randomized controlled trial found that yeast protein builds muscle, strength, and endurance as effectively as whey, establishing it as a sustainable, high-performance alternative for supporting muscle growth.
READ MORE →Front Microbiol, 2026
Yeast Protein Supports Gut Health and Healthy Aging by Favorably Shaping the Gut Microbiome
Using an ex vivo gut model, researchers found that yeast protein performs comparably to whey and soy proteins in boosting beneficial gut bacteria, reducing inflammation, and strengthening the gut barrier in older adult males — while also producing less gas and lower levels of TMAO, a compound linked to cardiovascular risk.
READ MORE →