Head-to-head comparison

Collagen Peptides vs Soy Protein Isolate: Which Has More Protein?

On paper, Collagen Peptides and Soy Protein Isolate solve a similar problem — protein intake — but they get there differently enough to be worth a direct look.

Collagen Peptides

90.0gprotein / 100g

370 cal · 0.5g fat · $$$ · Quality 0.0

Soy Protein Isolate

90.0gprotein / 100g

375 cal · 1.0g fat · $$ · Quality 0.9

Gram for gram, Collagen Peptides and Soy Protein Isolate are close: 90.0g vs 90.0g of protein per 100g — a difference small enough that it shouldn't be the deciding factor.

Soy Protein Isolate pulls ahead on protein quality specifically (one of the highest-quality plant proteins, near-complete on its own), even in categories where Collagen Peptides wins on raw grams.

Soy Protein Isolate is the more budget-friendly pick ($$ vs $$$ for Collagen Peptides), worth weighing if cost matters more than the other differences here.

If you're eating plant-based, this comparison is moot — Soy Protein Isolate fits, Collagen Peptides doesn't.

Soy Protein Isolate's typical serving also delivers more leucine (2450mg vs Collagen Peptides's 400mg) — relevant if the goal is maximizing the muscle-protein-synthesis trigger per meal, not just total grams.

Verdict

The real deciding factor is dietary fit, not macros: choose Soy Protein Isolate if you need it to be plant-based, choose Collagen Peptides otherwise — the protein numbers are close enough that diet compatibility should lead.

Full nutrition comparison

Per 100gCollagen PeptidesSoy Protein Isolate
Protein90.0g90.0g
Calories370375
Fat0.5g1.0g
Carbs0.0g2.0g
Fiber0.0g1.5g
Quality score0.00.9
Relative cost$$$$$
Prep time1 min1 min

Frequently asked

Which has more protein, collagen peptides or soy protein isolate?

Collagen Peptides has 90.0g of protein per 100g compared to Soy Protein Isolate's 90.0g.

Which is lower in calories?

Collagen Peptides is lower in calories per 100g, at 370 vs the other's 375.