Research

Hormonal

Whey protein supports greater muscle hypertrophy and net muscle protein balance compared to soy protein when consumed in close temporal proximity to resistance exercise.

If your goal is maximizing muscle growth from resistance training, choose whey protein over soy protein. Consume about 20-25g of whey within 1-2 hours after your workout. While soy supports muscle growth, whey's faster digestion and higher leucine content lead to greater muscle mass gains.

GoodSupportsHIGH confidence
Evidence indicates that whey proteins result in greater muscle hypertrophy than soy proteins do and that mixed milk and whey proteins are more effective than simply energy in promoting hypertrophy.
Stuart M. Phillips et al. · Journal of the American College of Nutrition · 2009

Why this rating

Based on a review of multiple acute and chronic studies (n=241 subjects) showing consistent trends favoring whey.

Source

The Role of Milk- and Soy-Based Protein in Support of Muscle Protein Synthesis and Muscle Protein Accretion in Young and Elderly Persons

Stuart M. Phillips et al. · Journal of the American College of Nutrition · 2009

DOI 10.1080/07315724.2009.10718096

narrative_reviewCited 242×
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DOI resolved against Crossref · corpus check 2026-06-10

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