Soy vs Whey Protein: Which is suitable for athletes to build muscle!

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Written By Samarjit Sinha

Working out for 10 years | Has a home gym | CPD (UK) Certificate holder in Fitness

Soy vs Whey Protein: Which is Better for Muscle Building?

FeatureSoy ProteinWhey Protein
SourcePlant-based (Soybean)Animal-based (Milk, whey)
FormsPowder, soybeans, soya chunks, etc.Powder
ProductionGrinding and processing soybeansDrying leftovers from cheese production
TextureGrainierSmooth and creamy
TasteNutty, stronger flavorMild, often preferred in various flavors
Biological ValueLowerHigher
Fat ContentDoes not contribute to fat lossMay help reduce body fat and increase lean mass
CarbohydratesHigherLower (almost 0 carbs)
Testosterone ResponseLowHigh
Amino Acid ProfilesHigher in leucine, isoleucine, methionine, lysineComplete amino acid profile
Shelf LifeAbout a yearTwo years
Muscle BuildingLess effective for muscle growthMore effective, especially post-workout
SuperiorityInferior for muscle buildingSuperior for muscle building and health

Unless you are a vegan then whey is the best protein for muscle building. Whey has no cons unless you are a vegan or allergic to milk.

Even if you are allergic to milk, you can consume whey isolate protein powder. Isolates are costly, less calorie dense and do not cause any allergic reaction.

While whey is king when it comes to building muscle, soy has its place in your diet. Soy protein is so versatile almost all food items has it.

Soy vs Whey Protein

Soy protein is almost 90% protein, so for vegans this is equally a good choice.

Just, do not compare whey and soy protein for their effectiveness, price and speed of absorption.

whey protein

What Is Whey Protein?

Whey protein is a type of protein that is derived from whey, the liquid part of milk that separates during cheese production. Whey protein is often used as a supplement to help build muscle mass and to improve exercise performance. Although whey protein is generally considered safe, some people may experience side effects, such as bloating, gas, nausea, and headaches.

Benefits of Whey Protein

  1. Whey protein is thought to help with psoriasis by reducing itchy skin symptoms.
  2. Whey protein may help with weight loss by helping you lose weight and maintain your weight loss goals.
  3. Whey protein is packed with nutrients and amino acids, making it a great choice for athletes and those looking to improve their health overall.
  4. Whey protein is easy to add to your favorite recipes and has a mild taste with minimal aftertaste.
  5. Whey protein is a perfect addition to your favorite smoothies and recipes because it absorbs quickly and has a creamy texture.
  6. Whey protein is the perfect source of quick energy for athletes or anyone who wants an easy way to boost their fitness level.


This study in particular shows with whey consumption after workout and in the morning resulting in greater muscle growth and recovery.

Soy vs whey protein

What Is Soy Protein?

Soy protein is a protein that is isolated from soybean. It is a complete protein, as it contains all the essential amino acids for human health. Soy protein is popular with vegetarians and vegans, as well as people who are looking for a healthy alternative to animal-based proteins.

Benefits of Soy Protein

Soy protein is high in protein and has a range of benefits for athletes and individuals who want to increase their intake of protein.

  1. Soy proteins are low in saturated fats which are known to have medical implications for cardiac health.
  2. Soy proteins contain fewer carbs than other types of proteins, making it a good choice for people who want to reduce their carb intake.
  3. With 90% protein, consuming soy protein will boost your muscles.
  4. Soy might reduce harmful cholesterol like LDL.
  5. Soy protein can be used to make roti/chapati.

Source – soy benefits

[11 benefits of soy protein in detail]

Using soy protein

Whey Protein vs Soy Protein: Key Differences


Whey protein is from the animal sources while soy protein is from a plant sources.

Whey protein has high Bioavailability which makes it more effective for muscle gain and recovery. Soy protein does not have high Bioavailability which may lead to lower muscle gain and recovery rates.

However, soy is popular among vegan body builders.

Available Forms

Whey protein is a type of protein that comes in powder form. Soy protein is a type of protein that comes in the form of soybeans.

Soy also is available in the forms like soya chunks, soy protein powder etc.


Soy protein is produced by grinding soybean and processing them. Whey protein is produced by drying leftovers from cheese production. The key difference between the two is that whey protein is a complete protein, while soy protein is not.

Production of whey is costlier thus the price of whey is also much higher than soy. Whey is more refined to make whey isolate, which is coslier than whey concentrate as well.


Whey protein has a smooth, creamy texture, while soy protein has a grainier texture. This is due to the different manufacturing processes used to produce each type of protein powder.

Whey protein is made from milk, and the manufacturing process involves separating the whey from the casein. Soy protein is made from soybeans, and the manufacturing process involves grinding up the soybeans into a powder.

[Casein vs whey protein for weight gain]


Whey protein is typically smoother and has a more mild flavour, while soy protein is grainier and has a stronger, nuttier flavour. The additives and stabilizers in different brands also affect the taste. Most people prefer unflavored versions of both whey and soy protein, so they can add their own flavours and create a variety of tastes and textures with the addition of fruits and nuts.

However whey tastes like milk powder, a little bland. Soy protein powder tastes weird and it is not easy to get adjusted to that taste.

Whey is tastier than soy protein.

Whey is also available in lot of flavor than soy. Be it mocha, cookies & cream, mango etc.

Biological Value

Biological value is a measure of how well a protein is absorbed and utilized by the body. Whey protein has a higher biological value than soy protein, which means that it is more efficiently used by the body.

Whey is the highest quality protein that bodybuilders can use. Whey gets absorbed very quickly so it is often a popular choice of before/after workout shakes.

Soy protein tends to have a lower biological value than whey protein, which means that it is not as efficiently used by the body.

So even if soy protein is 90% protein per scoop, not all of it is usable.

[Best whey protein for athletes]


Whey protein helps reduce body fat and increase lean body mass while soy protein does not have a clear advantage over other protein sources for weight and fat loss.

Whey protein is generally is low in calorie than any vegan protein out there.


Whey has almost 0 carbs so you get pure protein which is most of us are after. In soy protein, it has plenty of carbs which will give you calories but the protein content will get less too.

Still soy is ahead of other vegan protein blends with 90% protein content.

Carbohydrates are essential nutrients that the body needs for energy. They are found in foods like bread, rice, pasta, potatoes, and fruits. Carbohydrates are broken down into glucose, which is used by the body for energy.

The impact of carbohydrates on protein absorption is controversial. Some research suggests that carbohydrates can help increase protein absorption, while other research suggests that they have no impact or may even decrease protein absorption.

The jury is still out on this topic and more research is needed to determine the true impact of carbohydrates on protein absorption.

Testosterone Response

whey protein has a high testosterone response while soy protein has a low testosterone response.

Testosterone is the primary male sex hormone and plays an important role in muscle growth and development. Whey protein is rich in amino acids, which are the building blocks of muscle tissue. Therefore, it’s not surprising that whey protein has a positive effect on testosterone levels.

On the other hand, soy protein is derived from plants and contains phytoestrogens, which are plant-based estrogens. These plant estrogens can bind to estrogen receptors in the body and reduce testosterone levels. That’s why soy protein has a negative effect on testosterone levels.

Amino Acid Profiles

Soy protein is higher in leucine, isoleucine, methionine, and lysine. Whey protein contains adequate amounts of essential and nonessential amino acids to support general health.

Whey is more complete than soy.

Shelf Life

Soy protein products have a shelf life of about a year, while whey protein products last for two years.

[Best plant protein powder in India]

Best budget whey protein under 1000

Whey or Soy for Building Muscle?

Whey is better for building muscle. It has all the amino acids that are great for building muscle.

Soy, not so much.

Whey is also great when you consume it after you workout, it will spread into your bloodstream much faster.

Whey also has a lot of leucine for your muscles.

What is Leucine?

Leucine is an important amino acid that helps with muscle protein synthesis. Leucine is only one part of a myriad of compounds that help your muscles grow. Leucine holds a special place in optimizing your gains because it helps with muscle protein synthesis.

Many believe leucine is what makes muscles grow.

Leucine is the key to muscle growth. Whey has more leucine than soy, so it is better for building muscle.

Finally, Which Is Superior?

If you’re looking to build muscle, you might be wondering which type of protein is better for you: soy protein or whey protein?

Soy protein is inferior to whey protein when it comes to performance and health. Whey has high bioavailability than soy thus you can absorb all of whey.

But you can not absorb all of soy that you consume.

Whey is very easily absorbed by the body and has been shown to promote muscle growth more effectively than soyprotein.

Whey is a complete protein, meaning it contains all of the essential amino acids that your body needs for muscle growth.

So, if you’re looking to build muscle, whey protein is superior to soyprotein in terms of both performance and health.


About The Skinny Author


Working Out for 10 years | Owns a home gym |Certificate course done on Improving Aerobic Fitness, Diet | CPD (UK) Accredited Certification on Fitness

Yo Friends, this is Samarjit! A skinny guy who is building his tiny home gym.

I have successfully gained 10 kgs in 10 months going to commercial gyms. And I have been working out on and off for about 10+ years now.

I have gone swimming, done martial arts, Olympic lifts and body-building-type workouts!

I canceled the gym subscription as I was more into making my home gym for workouts. And getting ready, then getting my cycle and ride to the commercial gym seemed a drag after 10 hours in the office.

Thus, I needed a home that I could access at any moment!
And I started building my home gym!

I had to research a lot to build my home gym and decided to share effective, budget-friendly home gym machines, and nutrition to buy as per your goals here in

If you have question then contact me here

Ps: The author is highly experienced with making small workout routines, understanding and guiding people to get gym equipment, and setting up the home gym as per their Fitness goals.

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