Is Your Protein Powder Messing With Your Hormones?

Functional Medicine Practitioner By William Cole, D.C., IFMCP
Functional Medicine Practitioner
Dr. Will Cole, D.C., IFMCP, is a leading functional medicine expert who specializes in clinically investigating underlying factors of chronic disease and customizing a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. Cole is also the bestselling author of Ketotarian and The Inflammation Spectrum.

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People love their protein powders. They can be an easy addition to your morning smoothie for a quick, filling breakfast or even added to baked goods to bulk up the nutritional value. But some of our patients at our functional medicine health center find that when they use different protein powders, they notice some strange things happening:

  • Acne
  • Rashes
  • Digestive problems
  • Menstrual irregularity

So can protein powders mess with our hormones? Let’s break down how the different protein powders can directly affect your hormones.

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Found in our skin, cartilage, tendons, bones, ligaments, blood vessels, and more, this protein is responsible and needed for a healthy metabolism as well as our own collagen production. It is comprised of three amino acids: proline, glycine, and hydroxyproline. Your body produces all three but not enough to be beneficial, so supplementation through diet is important. Our bodies need about 15 grams of glycine a day—but the average person typically consumes only about three. You can get collagen in a few different forms all containing different subtypes of collagen:

  • Bovine collagen: This collagen found in cows has both Type I and Type III collagen. Why I love it so much is that Type I is what is most common in the human body to form tendons, bones, and ligaments and Type III works to form connective tissue, bone marrow, and cartilage. Just make sure to look for grass-fed.
  • Chicken collagen: This contains Type II collagen found in chicken bones and cartilage.
  • Fish collagen: My favorite! Also referred to as marine collagen, it is another one of my all-time favorites next to bovine collagen. Not only does it provide the essential Type I collagen, but it is also one of the most bioavailable because the collagen peptides are smaller particles.
  • Eggshell membrane collagen: This kind of collagen contains both Type I and Type V collagen, which work together for healthy joint and connective tissues and help encourage muscle growth.

Hormone conclusion:

You really can’t go wrong with collagen since most people can tolerate it well and it contains important collagen subtypes found in our own bodies, generally giving it a minimal, if any, effect on hormones. Its increased bioavailability is also a plus.

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This is the main protein found in cow’s milk and is commonly isolated for use in protein powders since it is slower to digest. Your body is able to use it longer, making it perfect for building new muscle tissue and muscle growth.

Hormone conclusion:

The main type of casein, beta-casein, has two subtypes: A1 and A2. The A1 subtype is what is most commonly found in milk products in grocery stores across the United States. The reason is that most American cows have casein gene mutations due to thousands of years of crossbreeding different kinds of cows. A1 casein is one reason dairy is hard for some people to tolerate. Research has shown that A1 can be a trigger for digestive problems and inflammation, which wreak havoc on your hormones. Beta A2 casein, however, is the OG, ancient casein and has been shown more digestible and higher in vitamins.

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Egg white.

This is a highly bioavailable protein option and is used as the standard for determining the bioavailability of other sources. It’s also fantastic because it provides all of the necessary amino acids your body needs.

Hormone conclusion:

The albumin in egg whites can be a source of inflammation for some, but if you can tolerate eggs, well, then, this is one of the better options.

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In the process of making cheese, milk is curdled and strained, leaving a semi-clear liquid, which we know of as whey. It is considered a complete protein with extremely high amounts of the amino acid leucine, which is essential for protein synthesis.

This type of protein powder is usually the most cost-effective option.

Hormone conclusion:

Whey is a great bioavailable protein source, but since it is still dairy-based, it's still loaded with casein, which can cause runaway inflammation in some people and further perpetuate hormonal problems. If dairy isn’t an issue for your body, just make sure you consume only grass-fed whey.

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We can’t talk about protein sources without mentioning the ever-controversial soy. Soy protein comes from de-hulled and defatted soybeans, which are then further processed to achieve three different forms: soy concentrates, soy isolates, and soy flour.

Hormone conclusion:

Soy is considered a phytoestrogen, which are plant-derived estrogens that are not produced in the endocrine system but are consumed from eating these types of plants. Soy is one of the most notable phytoestrogen out there and can have a pretty intense effect on your hormones. For women who are estrogen dominant and men, this can potentially be a problem. If you are going to go for soy, make sure you are looking for non-GMO varieties.


Compared to other plant- or animal-based protein powders, it is one of the lowest in protein content. While hemp is filled with other great factors such as fiber and omega fat, which is needed for a happy and healthy gut and brain, it contains only about 30 to 50 percent protein by weight compared to 90 to 100 percent of other choices. And not only is the protein content lackluster, but the amount it does have is less bioavailable than animal, pea, or even rice proteins.

Hormone conclusion:

There are not many negative hormonal side effects of this type of protein. In fact, since it provides loads of vitamin E, fiber, iron, and essential fatty acids, it can be a great choice since your body can’t produce these kinds of fats on its own and must be part of your regular diet.


Since it contains all nine essential amino acids, rice is considered a complete protein source. It is lower in lysine than whey protein but is almost as bioavailable as beef!

Hormone conclusion:

Because of its bioavailability and protein content, rice is a decent option as long as you can tolerate grains. Since they can be an inflammatory source for some, it could end up throwing off hormones and contributing to skin conditions like acne and rashes.


Derived from yellow split peas, this protein powder contains all nine essential amino acids. However, three of them are in very small amounts, so it may still be necessary to pair it with a complementary protein. Studies show that it can help keep you full for longer, which can make it perfect for adding to morning smoothies.

Hormone conclusion:

For those who want a plant-based option, this is a good one—but remember, you need to pair it with a more complete protein such as rice in order to reap the amino acid benefits (as long as grains and legumes are not a problem for you). Some people don't tolerate legumes, even podlike legumes like peas, so for these people, pea protein can throw off their digestion and hormones. If your stomach is at all irritated when you consume legumes, avoid pea protein.

Sacha inchi.

Also known as the Inca peanut, this seed found in Peru is a complete plant protein containing every single essential amino acid at 9 grams of protein per serving.

Hormone conclusion:

Its high omega fat content makes this a perfect source for helping healthy hormones. Since it is plant-based, though, it will not be as bioavailable as collagen, but for those wanting a plant-based complete protein without grains, this is probably my favorite choice!

Pumpkin seed.

Pumpkin lovers can take their obsession to a whole other level with the addition of pumpkin seed protein powder. It's considered a complete plant protein with all nine amino acids at 12 grams of protein per 1-cup serving.

Hormone conclusion:

Because pumpkin seed protein is high in healthy fats (with 12 grams per cup), it is good for helping keep hormones balanced, a healthy brain, and providing long-lasting sustainable energy. Some people don't tolerate seeds, so for these people, this is a no-go.

For all of these options, read the label. If you're experiencing imbalances with your protein powder, it's not always the protein itself that's a problem—oftentimes it is the added ingredients that are the issue. Watch out for sugars and fillers and always go for organic with the fewest added ingredients possible.

And remember, whole, real food should be your primary source of protein, but protein powders can be a nice option if you are on the go, want to mix things up, around a workout, or just as an addition to your favorite smoothie recipe.

Want to stay away from powders? These are the best plant-based whole food protein sources.

William Cole, D.C., IFMCP
William Cole, D.C., IFMCP
Will Cole, D.C., IFMCP, is a leading functional-medicine expert and a Doctor of Chiropractic. He...
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