Quick verdict: Whey protein has a slight edge for muscle protein synthesis due to its superior leucine content and complete amino acid profile. But the gap is smaller than most people think — and for vegans or those with dairy sensitivities, a quality plant protein (especially pea-based) can absolutely support muscle growth when dosed adequately. The best protein is the one you'll actually use consistently.

Whey vs. Plant Protein: The Question Worth Asking Properly

This debate generates a lot of heat for what is ultimately a nuanced answer. The right choice depends on your digestive tolerance, dietary restrictions, training goals, and frankly, which one you actually enjoy drinking.

What doesn't depend on those factors: the quality of the protein source matters. A $15 plant protein blend with a proprietary amino acid matrix hiding 10g of glycine padding is not the same as a transparent, third-party tested pea protein isolate. Same goes for whey — whey concentrate from commodity dairy is not the same as whey isolate from grass-fed cows.

So the comparison below is between quality representatives of each type: Momentous Whey Protein Isolate and Ritual Plant Protein+. Both are NSF Certified for Sport, both have full label transparency, and both are used by serious athletes.

Side-by-Side Comparison

Feature Momentous Whey Protein Isolate Ritual Plant Protein+
Protein per serving 24g 20g
Protein source Grass-fed whey isolate Yellow pea protein
Amino acid profile Complete (all 9 EAAs) Complete (all 9 EAAs)
Leucine per serving ~2.5g (estimated) ~1.6g (estimated)
Certifications NSF Certified for Sport + Informed Sport NSF Certified for Sport + Third-Party Tested + Vegan
Certifications note Dual-certified (rare) Vegan-verified
Added features 1 billion CFU probiotics Fermented trace minerals
Price $55.95 (~25 servings) $44.00 (~20 servings)
Cost per serving ~$2.24 ~$2.20
Cost per gram of protein ~$0.09 ~$0.11
Dairy-free No Yes
Vegan No Yes
Best for Muscle building, athletes, post-workout Vegans, dairy sensitivity, clean eating

The Science on Whey Protein

Whey is a byproduct of cheese production — the liquid left over after milk is curdled. Processed into powder, it became the gold standard in sports nutrition for good reason.

Whey isolate is the cleanest form. Unlike whey concentrate (70-80% protein by weight), isolate undergoes extra filtration to reach 90%+ protein content with minimal lactose and fat. This makes it easier to digest, appropriate for many people with mild lactose intolerance, and better suited for meeting daily protein targets without excess calories.

The leucine advantage is real. Leucine is the key amino acid that triggers muscle protein synthesis (MPS) — it's the molecular switch that tells your muscle cells to build. Research consistently shows you need around 2-3g of leucine per meal to maximally stimulate MPS. Whey isolate typically delivers 2.4-2.6g per 25g serving. That's the threshold in a single serving.

A 2023 meta-analysis in Nutrients analyzing 22 RCTs confirmed that whey supplementation leads to significantly greater gains in lean muscle mass and strength compared to placebo when combined with resistance training. The effect size is meaningful, not trivial.

Speed matters (a little). Whey is a "fast" protein — it peaks in the bloodstream roughly 60-90 minutes post-ingestion. This makes it well-suited for post-workout windows when muscle repair is active. That said, the importance of the "anabolic window" has been somewhat overstated by marketing — total daily protein intake matters more than timing for most people.

Momentous's specifics: 24g grass-fed whey isolate per serving, plus 1 billion CFU probiotics (DE111 Bacillus subtilis, a well-studied strain). NSF Certified for Sport and Informed Sport — dual certification is uncommon and signals serious quality control. Priced at ~$2.24 per serving, it's on the premium end, but you're paying for sourcing, certification, and manufacturing standards.

The Science on Plant Protein

Plant protein has come a long way from grainy, chalky powder that tasted like cardboard. Pea protein, in particular, has emerged as the most researched and highest-quality plant option.

Pea protein has a surprisingly good amino acid profile. Yellow split pea protein is rich in arginine, lysine, and BCAAs, including a decent leucine content. The main amino acid it's low in is methionine — which is why many plant protein blends combine pea with rice protein to create a more complete amino acid matrix.

Can plant protein build as much muscle as whey? This is where it gets nuanced. A 2020 double-blind RCT in the Journal of the International Society of Sports Nutrition found that pea protein and whey produced equivalent muscle thickness gains in young men over 12 weeks. But other research suggests the gap widens when matched gram-for-gram — plant protein's lower leucine content means you may need a larger dose to hit the same MPS trigger.

The key adjustment: If you're using plant protein for serious muscle building, bump the serving size up. A 30-35g serving of quality pea protein will deliver leucine content comparable to a 25g whey serving. Many plant protein users simply have two scoops post-workout.

Digestion is more variable. Some people digest plant protein beautifully. Others experience bloating and gas, particularly with rice protein or fiber-heavy blends. Pea protein isolate tends to be gentler than whole-food plant protein sources because the fiber has been largely removed.

Ritual Plant Protein+ specifics: 20g pea protein per serving from yellow split peas, with fermented sugar cane trace minerals (manganese, chromium). NSF Certified for Sport, vegan-verified, third-party tested. The fermentation process may improve mineral bioavailability, though the clinical evidence for this specific addition is limited. At ~$2.20 per serving, the cost is comparable to quality whey.

Key Differences Breakdown

1. Muscle Protein Synthesis (MPS) Stimulation

Winner: Whey protein (meaningfully)

Whey's higher leucine content (~2.5g vs ~1.6g per typical serving) gives it a direct mechanical advantage in triggering MPS. This isn't marketing — it's well-replicated exercise physiology. That said, you can close this gap by taking a larger serving of plant protein or by using a blend that includes methionine-rich sources.

2. Digestibility and Gut Tolerance

Winner: Draw (depends on the individual)

Whey isolate is highly bioavailable and well-tolerated by most people, including many with mild lactose intolerance (isolate has minimal lactose). Plant proteins can cause gas or bloating in some individuals, particularly those sensitive to legumes. But plenty of people digest pea protein with zero issues — and some people don't tolerate dairy-derived proteins well regardless of form.

3. Amino Acid Completeness

Winner: Effectively equal with quality products

Both Momentous whey and Ritual plant protein contain all 9 essential amino acids. Whey's profile is generally considered superior for muscle-specific purposes due to leucine content. But the distinction is less dramatic than often portrayed, especially when daily total protein intake is adequate.

4. Certifications and Safety Testing

Winner: Whey protein (marginally)

Momentous carries both NSF Certified for Sport and Informed Sport — dual certification is the highest bar in the industry. Ritual has NSF Certified for Sport and third-party testing. Both are well above average; Momentous's dual certification gives it a very slight edge for athletes in tested sports.

5. Dietary Compatibility

Winner: Plant protein (obviously)

If you're vegan, follow a dairy-free diet, or have a diagnosed dairy allergy — plant protein wins by default. Ritual's pea protein is also free from the top 9 allergens. No contest here.

Similarities

Both products share:

  • Complete amino acid profiles with all 9 EAAs
  • NSF Certified for Sport (third-party purity testing)
  • Transparent labeling — no proprietary blends
  • Added functional ingredients (probiotics vs. trace minerals)
  • Similar price per serving (~$2.20)
  • Clean formulas without artificial sweeteners, colors, or flavors

Price and Value

Momentous Whey Protein Isolate

  • $55.95 for ~25 servings
  • ~$2.24 per serving, ~$0.09 per gram of protein
  • Best price: Brand direct at livemomentous.com

Ritual Plant Protein+

  • $44.00 for ~20 servings
  • ~$2.20 per serving, ~$0.11 per gram of protein
  • Best price: Brand direct at ritual.com

At similar price-per-serving, cost is essentially a non-factor in this comparison. Dollar-per-gram of protein is marginally better for whey (24g vs 20g per serving). Over a month of daily use, the difference is a few dollars.

Who Should Choose Whey Protein

  • Omnivores focused on maximizing muscle protein synthesis
  • Athletes in drug-tested sports who need rigorous certification
  • Post-workout recovery (fast digestion + high leucine)
  • People who tolerate dairy well
  • Anyone wanting to maximize muscle gain per gram of protein

Recommended: Momentous Whey Protein Isolate — $55.95, dual NSF + Informed Sport certified

Who Should Choose Plant Protein

  • Vegans and vegetarians (non-negotiable)
  • People with dairy allergies or lactose intolerance
  • Those who experience digestive issues with whey
  • Athletes who prefer plant-based nutrition
  • Anyone who wants a vegan NSF-certified option

Recommended: Ritual Plant Protein+ — $44.00, NSF Certified for Sport, vegan

The Bottom Line

Whey protein has a real but modest advantage in muscle protein synthesis for most people in most contexts. If your goal is pure muscle gain and you have no dietary restrictions, a quality whey isolate is the evidence-based choice.

But plant protein — specifically quality pea protein — can absolutely deliver meaningful results. The difference at the population level is smaller than the supplement industry suggests. If you slightly increase your serving size or total daily intake to compensate for lower leucine per gram, a well-formulated plant protein is a legitimate alternative.

The worst choice is obsessing over whey vs. plant protein while undereating protein overall. Most people need significantly more protein than they're getting, regardless of source. Get adequate total intake first. Then optimize the source.

FAQ

Can I build muscle on plant protein alone? Yes. Multiple studies have shown comparable muscle gains between plant and whey protein groups, particularly when total protein intake is adequate. The key is hitting enough total protein (typically 0.7-1g per pound of bodyweight) and ensuring leucine is not chronically deficient. A slightly larger serving of plant protein can compensate.

Does whey cause inflammation or acne? Some people anecdotally report skin issues from whey, possibly linked to whey's effect on IGF-1 or its leucine-driven insulin response. The evidence is limited and individual variation is high. If you notice consistent breakouts after starting whey, switching to plant protein is reasonable.

Is there a better third option — like egg white protein? Egg white protein (albumen) is excellent — it has a high biological value, complete amino acid profile, and sits between whey and plant in terms of digestion speed. It's a solid choice for those avoiding both dairy and plant proteins, though typically more expensive and less widely available.

Should I take protein powder if I eat enough protein from food? No. Protein powder is a convenience tool, not a magic ingredient. If you consistently hit your protein targets from whole foods, you don't need supplements. Protein shakes are most useful for people who find it difficult to eat enough protein through food alone.

What's the best time to take protein powder? Consistently throughout the day. Total daily protein intake matters more than timing windows. If you lift, getting ~0.4g/kg of protein within a few hours on either side of training is a reasonable target — but hitting your daily total is far more important than precise post-workout timing.

Prices shown may vary. Links may be affiliate links.