One scoop of whey protein has over five times more of the key muscle-building amino acid (leucine) than one scoop of collagen protein—even though both have the same total protein.

Scientific Claim

In healthy older women, the amino acid profile of whey protein contains approximately 5.5 times more leucine and 2.7 times more essential amino acids per 30 g serving than collagen peptides.

Original Statement

“Their contents appear in Table 1 as per serving based on amino acid content provided by the manufacturer. ΣEAAs: WP = 15.4 g, CP = 5.6 g; Leucine: WP = 4.3 g, CP = 0.9 g.”

From study:Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

definitive

Can make definitive causal claims

Assessment Explanation

This is a direct, factual comparison of supplement composition from manufacturer data. No inference is needed—only reporting of measured values.

Evidence from Studies

Supporting (0)

No supporting evidence found

Contradicting (1)

Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Randomized Controlled Trial

Human

2020 Mar 1

The study shows whey protein helps muscles grow better than collagen in older women, but it doesn’t say how much leucine or other amino acids are in each, so we can’t tell if the 5.5x and 2.7x numbers are right.

Source Study

Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial.

Score: 66

DOI: 10.1093/ajcn/nqz332

Similar Assertions

Even though both protein shakes had the same amount of protein, the whey one made the key muscle-building amino acid (leucine) in the blood much higher than the collagen one.

89%

After drinking whey protein shakes every day for a week, older women’s muscles kept building up new protein even on days they didn’t exercise—collagen protein didn’t do this at all.

79%

Collagen peptide consumption results in improved nitrogen balance relative to whey protein in elderly populations.

79%

When older women drink whey protein shakes, their muscles start repairing and growing faster—especially if they also do leg exercises—while collagen protein shakes don’t do much unless they exercise, and even then, it’s much weaker.

77%

When rats ate a larger dose of regular whey protein, their blood had more leucine than when they ate the same amount of hydrolyzed whey protein an hour later.

74%