Whether you’re new to resistance training or a seasoned lifter, you’ve probably asked yourself this question: Should I go with whey or plant-based protein to build muscle? With so many options lining the shelves, it can be hard to know which one truly delivers when it comes to gains.

In this post, I’ll break down the differences between whey and plant-based protein using the latest research, and help you decide which one fits your goals best. Plus, I’ll link a few good options you can check out for yourself.

Whey Protein: Fast, Complete, and Proven

Whey protein comes from milk and is widely regarded as the “gold standard” for muscle growth. It’s a complete protein, meaning it contains all nine essential amino acids, and it’s particularly rich in leucine—one of the most important amino acids for triggering muscle protein synthesis (Tang et al., 2009).

Because it’s rapidly digested and absorbed, whey is ideal for post-workout recovery. Numerous studies have shown that whey protein is highly effective for increasing muscle mass when combined with resistance training (Phillips et al., 2009).

Pros:

• High in leucine

• Fast digestion

• Strong evidence base

• Often more affordable per gram of protein

Cons:

• Contains dairy—may cause issues for those with lactose intolerance

• Not suitable for vegans

Plant-Based Protein: Cleaner, Greener, and Surprisingly Effective

Plant proteins are derived from peas, rice, soy, hemp, and other plant sources. On their own, some of these can be lower in certain essential amino acids, but when blended (like pea + rice), they can provide a complete protein profile.

Recent research (Monteyne et al., 2023) has shown that when plant-based proteins are matched for leucine content, they can stimulate muscle protein synthesis just as effectively as whey.

A systematic review by Mariotti and Gardner (2024) further supports this, concluding that plant-based proteins, when consumed in sufficient quantities and combinations, can support muscle gains comparable to animal-based proteins.

Pros:

• Suitable for vegans and those with dairy intolerance

• Lower environmental impact

• Often easier to digest for sensitive stomachs

Cons:

• Usually requires slightly more to match leucine levels

• Some products can be gritty or chalky in texture

How Do They Compare?

When it comes to building muscle, both whey and plant-based proteins can do the job—but they differ in a few key ways:

• Amino Acid Profile:

Whey protein naturally contains all nine essential amino acids, with a high leucine content that makes it especially effective for stimulating muscle growth. Most plant-based proteins, unless blended (like pea and rice), may lack one or more essential amino acids. However, many modern formulas are now fortified or combined to offer a complete profile.

• Digestion Speed:

Whey is rapidly digested, making it a great option for post-workout recovery. Plant proteins tend to digest more slowly, which can be beneficial for sustained satiety, though not quite as ideal immediately after training.

• Muscle-Building Evidence:

Whey is backed by decades of research supporting its role in increasing lean muscle mass. Plant proteins are catching up, with newer studies showing that, when properly formulated and consumed in adequate amounts, they can support similar gains.

• Diet Compatibility:

Whey comes from milk, so it’s not suitable for vegans or those with lactose intolerance. Plant-based proteins, on the other hand, are dairy-free, vegan-friendly, and often easier on the stomach.

• Sustainability:

Plant proteins generally have a lower environmental impact, making them a more sustainable choice for those who are eco-conscious.

In short: Whey is a reliable, fast-acting option with a robust track record. Plant protein is a solid alternative—especially when blended and thoughtfully formulated—with added benefits for dietary inclusivity and sustainability

Top Picks (Affiliate Links)

Whey Protein:

• Optimum Nutrition Gold Standard Whey

Plant-Based Protein:

• Optimum Nutrition Gold Standard 100% Plant

So… Which One Wins?

Honestly? It depends on your lifestyle, preferences, and dietary needs.

• If you’re not vegan and want fast absorption with a strong evidence base, whey is a fantastic option.

• If you follow a plant-based diet or want a more eco-conscious choice, plant protein—especially in blended or fortified forms—is a powerful alternative.

The key to building muscle isn’t just what protein you use, but how consistently you train, recover, and eat to support your goals

References

• Mariotti, F. & Gardner, C.D., 2024. Dietary Protein and Muscle Health: Plant versus Animal Protein. Nutrition Reviews.

• Monteyne, A.J. et al., 2023. Leucine-enriched plant protein stimulates muscle protein synthesis similarly to whey protein in young men. Current Developments in Nutrition.

• Phillips, S.M., Tang, J.E. & Moore, D.R., 2009. Milk- and soy-based protein and muscle protein synthesis in young and elderly persons. Journal of the American College of Nutrition.

• Tang, J.E. et al., 2009. Whey vs. casein protein post-exercise. Journal of Applied Physiology.

• Watson, T.A. et al., 2024. Protein and amino acid adequacy in UK vegans. Journal of Human Nutrition and Dietetics (in press).

• Wolfe, R.R., 2017. BCAAs and muscle protein synthesis. Journal of the International Society of Sports Nutrition