Collagen vs. Whey Protein: Which Is Best for You?

As a key building block, protein helps you grow strong, stay healthy and sustain energy. While most doctors and dietitians recommend getting protein primarily from the foods you eat, there are many reasons you might consider taking a protein supplement.

Whether you're trying to build lean muscle or just need a filling, on-the-go breakfast, it seems like everyone from fitness pros to soccer moms is scooping powders into their smoothies, shakes or morning coffee.

While whey used to dominate the supplement aisle, more protein supplements have been edging their way onto supermarket shelves. And collagen protein has been leading the parade.

But whether you should ditch your current protein in favor of this mainstream variety depends on your goals. Here's what you need to consider before making the swap.

Ever opened a container of yogurt and had that watery stuff floating on top slosh out all over your desk? That's whey. That liquid is what's left over after milk has been curdled and strained during the cheese-making process, according to the Cleveland Clinic.

Along with casein, whey is one of the two primary proteins in dairy and is naturally found in foods like milk, Greek yogurt and cheese.

Whey protein powders have become a powerhouse in the supplement world for a few main reasons:

1. ‌Whey is a complete protein‌, which means it will usually contain all the essential amino acids (aka the ones your body can't produce on its own and you have to get from food), according to the Mayo Clinic.
2. ‌It's absorbed quickly by the body‌, making it an effective and efficient form of protein.
3. ‌Whey is a great performance supplement.‌ It can have a positive effect on metabolism and post-workout recovery, according to a July 2017 study published in ‌Nutrients‌. It can also help promote gaining lean muscle mass, according to a 2013 study in the ‌Journal of the American College of Nutrition‌.
4. ‌It's linked to lower blood pressure and inflammation‌, according to a small December 2016 study in the ‌American Journal of Clinical Nutrition‌ and a July 2012 study in ‌Lipids in Health and Disease‌, which tied whey to less oxidative stress.

Although whey has a bunch of benefits, it's not without its drawbacks:

1. ‌The taste isn't always great.‌ Au naturel whey protein powder can be bitter, which is why most whey supplements come in an array of enticing flavors — such as traditional chocolate and vanilla as well as exciting options like Peach Swirl and Cinnamon Bun. But while these may sound delicious, it can be hard to mask the bitter flavor.
2. ‌It can be high in sugar.‌ "Whey supplements tend to be flavored and sweetened with sugars or artificial sweeteners, which can have the opposite effect you're looking for when it comes to being healthier, fighting chronic illnesses or weight loss," Zeitlin points out. If you do choose a flavored whey protein powder, look for one with minimal added sugars, Zeitlin recommends.
3. ‌Whey contains dairy and lactose.‌ Whey is derived from dairy, so people with a dairy allergy should avoid it. Most whey powders only contain a minuscule amount of lactose — whey protein isolate, in particular, contains the least lactose, per a May 2021 review in ‌Foods.‌
4. ‌Whey can cause stomach upset.‌ Whey can cause gastrointestinal discomfort, according to the Mayo Clinic. So, if your stomach doesn't feel too hot after drinking some whey protein, it's probably best to cut it from your diet.

Collagen is also a type of protein that plays an important role in building and supporting our bones, cartilage, skin, hair, eyes and digestive system, according to Boston University. There are more than 28 different kinds of collagen found in the human body, making it our most abundant protein and essential from head to toe.

"Collagen is a protein that we actually make on our own, but we lose it over time," says Brigitte Zeitlin, RD, owner of BZ Nutrition. Starting in our 20s, our bodies begin producing less collagen each year — a decrease that is exacerbated by elements like sun exposure and smoking.

There are ways to remedy this collagen loss, though. Eating foods high in vitamin C (like citrus fruits, strawberries and red bell peppers), foods high in collagen (such as seafood, meat and eggs) and taking collagen peptide supplements can promote the body's collagen production, Zeitlin says.

The latest darling of the supplement world, collagen also boasts a number of its own benefits for fitness, health and wellness:

1. ‌Collagen helps produce lean muscle.‌ Combining collagen supplements with a resistance training plan can help produce more lean muscle mass than resistance training alone, according to an October 2015 study in older men in ‌The British Journal of Nutrition‌.
2. ‌Collagen may help reduce inflammation.‌ It may and ease joint pain in people with osteoarthritis, according to a February 2017 study in the ‌Journal of Arthritis‌. But, more research is needed to confirm these findings.
3. ‌Collagen may improve your skin.‌ Orally supplementing with collagen may help improve skin elasticity, according to an August 2014 study in ‌Skin Pharmacology and Physiology‌.

Collagen isn't perfect for everyone. Before you buy, consider these drawbacks:

1. ‌It can contain fish:‌ Unlike whey, collagen is not made from milk and probably isn't as likely to cause stomach upset. However, some collagen supplements are marine-based, which means they're derived from fish or shellfish. So, anyone that has allergies to either of these foods should avoid marine-based collagen.
2. ‌Collagen isn't vegetarian-friendly:‌ Like whey, collagen is also an animal-derived product, either made from cows or fish. So, vegetarians and vegans may want to look for plant-based protein powders instead.

Well, it depends on what you're looking for.

Both supplements are excellent for promoting lean muscle gains when paired with resistance-style training. However, whey protein may increase resting metabolic rate more than collagen, according to a September 2019 ‌Nutrients‌ study of women with overweight.

Whey protein can be more beneficial for changing body composition but collagen does have less associated side effects. Especially for those with dairy sensitivity or lactose intolerance, collagen may be a better option.

While whey protein may taste better with the various flavors available, collagen can be more dynamic, as it's usually unflavored and can be easily added to your favorite smoothie.

"Collagen is naturally unflavored, so it makes a great protein supplement to add to foods — it won't change or obscure the flavor of your foods," Zeitlin says.