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Editor’s note: Collagen supplements are everywhere—but what’s real and what’s hype? In today’s piece, Priya Nagwani, a nutritionist and certified weight management coach, walks you through what really works, drawing from both research and personal insights, to help you understand when collagen supplements might (or might not) be worth your time and money.
As a nutritionist, I’m often asked about collagen supplements: whether they really work, which type to choose, and if they’re worth the investment. But my deepest understanding of collagen came from a personal experience.
My husband has struggled with gut health issues for years. His IBS (Irritable Bowel Syndrome) triggers were a constant challenge (where you experience frequent stomach upsets and discomfort). The gut becomes sensitive and easily gets irritated. It’s partly because the protective lining of the intestines isn’t working as well as it should.
That’s when I found studies suggesting that collagen could help strengthen this weakened intestinal lining.
We decided to try collagen supplementation for four months. The results were subtle but meaningful: his digestive system calmed, and flare-ups reduced noticeably.
I tried myself, too, but didn’t see significant changes in my own skin—which wasn’t a concern for me anyway.
This experience led me to dive deeper into understanding collagen supplements. Whether you’re considering collagen for gut health like we did, or for its better-known benefits for skin and joints, here are the key things you need to know.
I. What is collagen?
It’s the most abundant protein in your body, making up about 30% of your total protein content and about 80% of your skin’s protein. Think of collagen as your body’s structural framework—it’s the protein that provides strength and support to everything from your skin and bones to your muscles and tendons.
When people call collagen the “glue” that holds our bodies together, they’re quite literal: it helps hold different layers of tissues together and gives them their strength. This is why collagen is so important for skin firmness, bone strength, and joint health.
Here’s what makes collagen particularly interesting: your body naturally produces it, but this production starts declining by about 1% each year starting in your late 20s. This decline shows up in various ways: skin becomes less firm, joints get stiffer, and injuries take longer to heal. And this process can speed up due to factors like excessive sun exposure, smoking, chronic stress, or poor nutrition.
This is why adequate protein in your diet is crucial: your body needs those building blocks to maintain and repair collagen-rich tissues, even as natural production declines.
II. How is collagen different from regular protein?
An important distinction: collagen isn’t a complete protein. Think of whey protein or the protein in your chicken breast as a general contractor: they contain all nine essential amino acids your body needs for overall growth and repair. They can handle any protein-related job in your body.
Collagen, on the other hand, is more like a specialist: it lacks some essential amino acids, so you shouldn’t rely on it as your main protein source.
What makes collagen special, though, is its unique amino acid profile. It’s particularly rich in glycine, proline, and hydroxyproline—specific amino acids that help maintain connective tissues in your body.
So even if you’re getting enough protein from your diet, some can consider collagen supplements for targeted goals like supporting joint health, skin elasticity or gut repair. It’s not about getting more protein—it’s about getting these specific amino acids for specific purposes.
III. The three types of collagen you should know about
Not all collagen is the same. Your body has over 28 different types that serve different purposes. When you’re looking at supplements, you’ll mainly encounter Types I, II, and III. Each type works differently in your body:
Type I collagen is the most abundant in your body, particularly in your skin, bones, and tendons. This is your go-to for skin health and bone strength. When people talk about collagen for beauty benefits—like improving skin elasticity or reducing fine lines—they’re usually talking about Type I.
Type II collagen is specifically found in cartilage and focuses on joint health. If you’re looking to support healthy joints or address joint discomfort, this is the type you want to look for. (More here.)
Type III collagen usually works alongside Type I, supporting skin elasticity and blood vessel strength. You’ll often find Types I and III combined in supplements targeting skin health.
Knowing these differences helps you choose the right collagen supplement. If you’re mainly concerned about skin ageing, look for Type I (paired with Type III). But if you’re dealing with joint issues, Type II is what you want to focus on.
IV. Understanding collagen supplements and how they work
The collagen in supplements isn’t exactly the same as what’s in your body.
Natural collagen molecules are too large for your body to absorb directly. That’s why supplements use processed forms of collagen that are broken down into smaller pieces that your body can actually use.
The most common form you’ll find is hydrolyzed collagen (also called collagen peptides), where collagen has been broken down into shorter chains of amino acids. This makes it easier for your body to absorb. These dissolve easily in both hot and cold liquids, which is why you can add them to your morning coffee or smoothie or soup.
You might also encounter gelatin— yes, the same thing used in desserts. While it’s also a form of processed collagen, it’s only partially broken down. This is why it gels when mixed with water and is great for cooking, but isn’t as easily absorbed by your body as hydrolyzed collagen.
For joint health specifically, some supplements use undenatured collagen. This form keeps the collagen closer to its natural state.
A word of caution: scientists are still debating how effectively the collagen you take as supplements actually reaches and benefits target areas like your skin or joints.
Hydrolyzed collagen typically requires about 10 grams daily for skin and general health benefits.
If you’re taking Type II collagen specifically for joint health, the dose is much smaller – around 40 milligrams daily.
For best results, take your collagen on an empty stomach, preferably before breakfast.
V. Where does supplement collagen come from?
Collagen supplements come from different animal sources, and each source provides different types of collagen:
Bovine (cow) collagen is rich in Types I and III, making it popular for skin and bone health.
Marine (fish) collagen contains primarily Type I and is known to be easily absorbed.
Chicken collagen is rich in Type II, making it a common choice for joint health.
For those who prefer natural options, bone broth is a fantastic way to consume collagen, though it’s less concentrated than supplements.
One important note (from the New York Times): Be wary of products marketed as “plant-based collagen.” These products don’t actually contain collagen, and while they might claim to support collagen production, there isn’t solid science to back this up.
VI. Do you need collagen? Here’s a framework to decide
I approach supplements with the philosophy that they should complement, not replace, a balanced diet. Here’s how I guide clients in deciding whether collagen is right for them:
Define your goals: What specific concern are you trying to address — skin elasticity, joint health, or gut issues? Since collagen works differently for different concerns, being clear about your goal is essential.
Be realistic about results: Collagen isn’t a quick fix. You’ll need to take it consistently for 4-8 months to see potential benefits. Ask yourself if you’re ready for this commitment.
Consider your diet: While collagen has specific amino acids that support connective tissue, a protein-rich diet with foods like bone broth can provide similar building blocks. Collagen supplements should complement—not substitute for—good nutrition.
Check your budget: Quality collagen supplements can be pricey. If this isn’t sustainable for you, focus first on protein-rich whole foods.
Think holistically: Remember that collagen works best as part of an overall healthy routine. No supplement can replace the basics: a balanced diet, good hydration, proper sleep, and regular exercise.
My professional and personal verdict
As a nutritionist, my approach to collagen is practical: I recommend it to clients with specific concerns like ageing skin, joint discomfort, or gut health issues—but always with clear expectations. It’s not a must-have for everyone, especially if you’re meeting your protein needs through a balanced diet.
Let me be clear, again: collagen is essentially just a specific combination of amino acids, which you can get from protein-rich foods. Sometimes, the benefits people see might even come from other ingredients added to collagen supplements, like vitamins or antioxidants. This is why understanding your specific needs is crucial.
My personal experience reflects this view. While I don’t take collagen daily myself, I continue to monitor its effects on my husband’s gut health. By trying different brands, we’ve learned that results can vary, possibly due to different formulations and added ingredients.
In short, collagen isn’t a magic solution. If you decide to try it, remember three things: start with a clear goal, choose the right type for your needs, and be patient with results.