Collagen Protein vs Whey Protein: they’re both popular, but they serve very different purposes. As a dietitian, I'm going to break down what actually matters when choosing between them.
Jump to:
- What’s the Difference Between Whey Protein and Collagen Protein?
- A Closer Look At Collagen
- A Closer Look at Whey Protein
- Collagen vs Whey for Muscle Growth
- Collagen vs Whey for Weight Loss
- Collagen vs Whey for Skin Health
- Collagen vs Whey for Joint Health
- Can You Take Collagen and Whey Together?
- Summary - Collagen Protein vs Whey Protein
- The Research on Collagen
- FAQs
Let's start with the basics...
What’s the Difference Between Whey Protein and Collagen Protein?
Whey Protein
Whey protein is a complete protein made from milk. It contains all nine essential amino acids, which makes it ideal for muscle repair and growth. This is why it's often recommended after workouts or as a convenient way to meet daily protein needs.
There are a few types of whey protein: concentrate, isolate, and hydrolysate. They differ slightly in how they’re processed and how quickly they’re absorbed, but they all provide a high-quality source of protein.
Collagen Protein
Collagen protein is made from the connective tissues of animals, usually from skin, bones, or cartilage. It is rich in specific amino acids like glycine, proline, and hydroxyproline, which are important for skin, joint, and gut health.
Unlike whey, collagen is not a complete protein. It lacks enough of certain essential amino acids like tryptophan, so it’s not the best choice if you're trying to build or maintain muscle.
See a summary of the main differences between whey and collagen below.
A Closer Look At Collagen
What is collagen?
Collagen is a naturally occurring protein found in the human body. It is responsible for forming skin, hair, nails, joints and connective tissues. Although the body naturally makes collagen on it's own, as people age this process becomes harder and will begin to slow down.
From the age of 20, we start to lose about 1% of the collagen in our skin per year. After menopause, falling oestrogen levels lead to a further reduction in collagen production.
This is why many individuals will choose to take collagen supplements to help supplement this process.
What are the nutrition benefits of collagen?
- Supports skin health: As collagen levels drop over time, our skin loses its elasticity, which results in the skin losing its bounce and becoming more susceptible to wrinkle formation.
- Joint and bone health: Helps alleviate joint pain and promote bone density by reducing inflammation and supporting the structure and function of connective tissues.
- Digestive health: Collagen contains glycine, an amino acid that plays a role in maintaining the integrity of the intestinal lining. This may help support gut healing, particularly in people with increased intestinal permeability (sometimes called “leaky gut”).
- Hair and nail growth: While most of the collagen research focuses on skin rather than hair directly, there’s still a connection. A healthy scalp (which is skin, after all!) creates a better environment for hair growth. Plus, the amino acids in collagen — especially proline and glycine — are used by the body to help build keratin, the structural protein that makes up both hair and nails. So while indirect, collagen may help support stronger hair and nails.
What are the cons of collagen?
Collagen is not a complete protein because it does not contain all 9 essential amino acids such as tryptophan. Therefore it fails to provide comprehensive support for muscle recovery or overall bodily functions.
Currently only animal sources provide collagen. These include bovine (cows), marine, and poultry. People who follow vegetarian and vegan lifestyles will need to find different methods to maintain healthy skin and joints.
My favorite collagen powder
FullWell Unflavored Collagen Peptides Powder: This one’s my personal favorite! I love FullWell as a brand—all of their products are rigorously third-party tested, and this collagen powder is safe to take during pregnancy and breastfeeding. Each scoop gives you 15 grams of type I and III collagen, the types most supportive of skin, hair, nails, and connective tissue. Plus, it's unflavored, so it blends easily into smoothies, coffee, or even yogurt without changing the taste.
Vital Proteins: Another solid option! This one provides 20 grams of collagen per serving, which is a clinically effective dose for things like skin and joint support. It also mixes really well into hot or cold drinks with no weird texture or taste—always a win!
A Closer Look at Whey Protein
Nutritional Benefits of Whey Protein
Generally, people pick a protein with the goal of simply meeting their protein needs or building and supporting muscle mass. In this case, you need to consider the quality of the protein.
Whey is a good option because:
- It contains all 9 essential amino acids - stimulates muscle building to its fastest pace
- Contains leucine - an amino acid that acts as a switch turning on the muscle building process
- Is easily digested and absorbed
Cons of Whey Protein
Whey protein contains lactose which may lead to digestive discomfort such as gas, bloating, cramps and diarrhea in certain individuals.
Protein powders can be a source of ultra-processed ingredients such as added sugars, refined vegetable oils, excessive sodium, and artificial sweeteners which may contribute to unnecessary side effects such as gas and bloating.
My favorite whey protein powder
Naked Whey: I like this brand because it contains just one ingredient—whey. It also carries the Informed Choice logo, which means it's part of a quality assurance program that tests supplements monthly for banned substances.
Collagen vs Whey for Muscle Growth
If your main goal is building or maintaining muscle, whey protein is the clear winner.
Here’s why:
- Whey is a complete protein, meaning it contains all nine essential amino acids that your body can’t make on its own. This is important because muscle tissue repair and growth require a full spectrum of amino acids.
- It’s especially rich in leucine, which acts like a “trigger” for muscle protein synthesis — basically telling your body it’s time to build muscle.
- Fast absorption: Whey digests quickly, making it ideal to consume after resistance training or workouts when your muscles are most ready to take in nutrients.
- There’s strong research showing whey protein supports lean mass retention during weight loss and helps improve strength when combined with training.
On the other hand, collagen protein is not a complete protein — it lacks key amino acids like tryptophan. So while it’s great for things like joint health and skin support, it’s not ideal for muscle building or post-workout recovery on its own.
A Dietitian's Verdict:
If you're lifting weights, trying to preserve muscle while losing fat, or looking to boost your overall protein intake, whey is the better choice.
Collagen vs Whey for Weight Loss
Neither collagen nor whey protein will directly cause weight loss — because at the end of the day, weight loss comes down to consistently managing your overall calorie intake. If you're eating more than your body needs, even high-protein supplements won't move the needle in the right direction.
That said, whey protein is the better option if you're aiming to lose fat while preserving lean muscle. Here’s why:
- High satiety: Protein is the most filling macronutrient, and whey in particular may help reduce appetite and keep cravings at bay between meals.
- Muscle preservation: When losing weight, some muscle loss is inevitable — but whey protein helps minimize this. The more muscle you retain, the better your metabolism works.
- Convenient and versatile: Whey is easy to mix into smoothies, yogurt, oats, or even just water — making it a simple way to boost protein without much fuss.
A Dietitians Verdict:
Whey helps you stay full, supports your metabolism, and makes it easier to hold onto muscle — which is a huge win during weight loss.
Collagen vs Whey for Skin Health
First you need to nail the basics of nutrition for glowy skin. This means eating enough overall protein, ideally from whole foods, with support from protein powders if needed.
Once that’s in check, and you're aiming for long-lasting, youthful skin, collagen protein is the clear winner.
Collagen Protein and Skin
Large studies have concluded that supplementing with collagen (especially hydrolyzed collagen peptides) may help by:
- Supporting skin elasticity and hydration
- Reducing the appearance of fine lines
- Improving skin texture and firmness over time
Some studies have shown noticeable improvements after just 8–12 weeks of daily collagen supplementation — although individual results can vary.
A Dietitian's Top Tip: Start supplementing early. The truth is that you are better to supplement levels when your collagen production is still high rather than wait until levels naturally decline.
Whey Protein and Skin
Whey protein isn’t typically recommended for skin — and in some cases, it may even cause issues for certain individuals:
- Some people report breakouts or acne after consuming whey, particularly in higher doses. This could be due to hormonal effects (whey can increase IGF-1 levels, which may affect oil production).
- That said, not everyone reacts this way. If your skin tolerates whey well, it can still be part of a healthy, balanced diet.
A Dietitians Verdict:
Collagen is one of the few supplements that directly supports skin structure and appearance. Whey isn’t inherently bad for your skin, but it may contribute to breakouts in some individuals — especially when consumed in large amounts.
Collagen vs Whey for Joint Health
If you’re dealing with joint pain or just want to keep your joints feeling strong and supported as you age, collagen protein is the better choice.
BUT, as always you need to get the basics right first. This means consistently eating enough overall protein to support your body's muscles and joints. Ideally, that’s from whole foods, but a protein powder can help fill the gap if needed.
Collagen for Joint Health
Collagen is a major component of cartilage, the tissue that cushions your joints. As mentioned, as we get older collagen production declines. This can lead to stiffness, discomfort, or even injury.
Supplementing with collagen may help by:
- Supporting cartilage structure and regeneration
- Reducing joint pain and stiffness, especially in people with osteoarthritis or active lifestyles
- Improving mobility and flexibility over time
Several studies have shown that daily collagen supplementation can lead to significant improvements in joint comfort after about 12–24 weeks, especially when paired with regular movement and a balanced diet.
Whey Protein and Joint Health
Whey protein isn’t directly involved in joint repair, but that doesn’t mean it’s useless in this context.
Here’s what it can do:
- Supports muscle mass, which indirectly helps joints by reducing strain on them
- Provides essential amino acids that support overall tissue repair
- Helps maintain strength during weight loss or aging, which contributes to better joint function
However, unlike collagen, whey doesn’t provide the specific amino acids (like glycine and proline) that are most involved in rebuilding cartilage and connective tissue.
A Dietitians Verdict:
For joint health, collagen has the edge. It's specifically designed to support the tissues in and around your joints.
Whey still plays a supportive role, particularly if you’re trying to maintain strong muscles to take pressure off your joints.
Can You Take Collagen and Whey Together?
Yes! And this can be a really smart approach depending on your goals. It's typically what I do as a dietitian and what I recommend to many of my clients who are interested in supplements.
Because collagen and whey proteins have different amino acid profiles, they serve different purposes. So they’re not competing with each other. In fact, using both can help you cover more nutritional bases.
Whey is great for muscle building, recovery, and general protein intake. Collagen is more targeted toward skin, joints, and gut health.
A common routine might be using whey after a workout to support muscle repair, and then adding collagen to your morning coffee or smoothie for extra support for joints and skin.
You're not limited to choosing just one. If your overall protein needs are met and you're using high-quality supplements, combining the two can be a great addition to your routine.
A Dietitians Verdict:
You can absolutely take collagen and whey together. They complement each other nicely — it’s just about using the right tool for the right job.
Summary - Collagen Protein vs Whey Protein
They both serve very different purposes and for that matter one is not necessarily better than the other.
Choose whey protein if:
- Cost is a determining factor: You’re going to get more bang for your buck with whey protein powder
- Your goal is to support muscle growth or recovery
- You need a convenient way to increase your daily protein intake
- You’re doing resistance training or trying to preserve lean mass during weight loss
Choose collagen protein if:
- You’re focused on skin health, joint support, or gut health
- You already meet your protein needs through food but want targeted collagen benefits
- You prefer something that dissolves easily in hot drinks like coffee
You can also use both. Many people use whey after workouts and add collagen to their morning routine for joint and skin support. Just remember that collagen doesn’t replace other high-quality protein sources.
The Research on Collagen
If you want to learn more and dive further into the clinical evidence behind collagen supplements I recommend checking out the below papers, all linked for your convenience:
2021 Meta-analysis: Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis
2023 Meta-analysis: Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis
FAQs
Whey protein is better for muscle growth because it's a complete protein and high in leucine.
Yes! Many people take whey after workouts and collagen in their morning coffee to support joints and skin.
Final Thoughts
Collagen protein vs whey protein isn’t about which one is better overall. It’s about choosing the right tool for the job. If you want muscle support, go with whey. If you're more focused on skin, joints, or aging well, collagen might be worth adding in.
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