Collagen has certainly been a trendy supplement option over the last several years. Just walk into your nearest health store, supplement shop, or even beauty aisle and you’ll see options abound. But all that visibility does come with a lot of misinformation—as well as, ahem, less than ideal products and misleading claims. So we decided to sort it all out for you. Here, everything you need to know.
What is collagen?
Collagen describes a family of proteins1 that comprise the most abundant proteins in the animal kingdom. In fact, there are at least 28 kinds of collagen2 that we know of that exist in vertebrates (yes, us included), but types I, II and III are the most common in the human body.
Collagen’s role in the body is both simple and complex (at the cellular level): It helps make up the structure of our skin, bone, cartilage, and muscle, with the purpose of helping tissues be more elastic and withstand stretching (So, for example, it keeps skin looking young and supple).*
What causes collagen loss?
We actually make our own supply of collagen, via our cells' fibroblasts (assuming they have the amino acids and other required nutritional building blocks they need). In fact, it’s made by the body throughout the lifetime; however it also decreases with age, and your natural levels can also be reduced by environmental factors and stressors, such as sun damage and high-sugar diets3.
What are collagen supplements role in natural collagen levels?
This is where collagen supplements come in: Collagen supplements are broken down, digestible forms of collagen (derived from things like cows, fish and chickens), usually in a powdered form.* These are often referred to as hydrolyzed collagen, collagen hydrolysate, collagen peptides, or gelatin.
- Hydrolyzed collagen: Collagen that has been broken down into collagen peptides or gelatin through the process of hydrolyzation. All collagen supplements, to a degree, have been hydrolyzed. These are often also called collagen hydrolysate.
- Collagen peptides: Collagen that is fully broken down into digestible, short chains of amino acid chains, aka peptides.
- Gelatin: A form of collagen supplement that has not been fully hydrolyzed and therefore will "gel" in recipes.
The peptides in collagen powders are made up of amino acids, the building blocks of all proteins. There are an estimated 20 to 22 amino acids 4that make up every protein in the human body, including arginine, glutamic acid, lysine, proline, and tyrosine.
However, we must note that collagen is not a complete protein—meaning it’s low in or does not contain all 9 of the essential amino acids (which are phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, and lysine) that the body can't produce itself. However, it typically contains some amount of all of these except tryptophan And collagen can absolutely still help individuals meet their daily protein intake5.*
Benefits for skin.
It promotes your skin's natural collagen and elastin production.*
The two main layers that make up the skin are the epidermis and the dermis. The dermis contains fibroblasts, which are cells that produce elastin and collagen. For the skin to function normally and appear youthful, the structure of the dermal layer must be maintained, but as we age the structure suffers because aged fibroblasts produce less collagen7. This results in signs of aging, like sagging and fine lines, which are usually most prominent on the face.
As the production slows, collagen supplementation can help support the body's natural production.* "It can help with skin wrinkling, providing the skin one of its basic ingredients to stay firm and taut," says Taz Bhatia, M.D., an integrative medicine physician and mbg Collective member.*
The research 6shows that these collagen peptides are able to support skin elasticity and dermal collagen density6.* How? Well hydrolyzed collagen peptides have been shown to help promote the body's natural production of collagen8 and other molecules that make up the skin, like elastin and fibrillin.*
Now, for so long much of the rhetoric around ingesting collagen was about how the molecule was too large to be easily absorbed. This is why the misconception that the skin benefits of collagen supplements are all hype abounds. But research has shown that hydrolyzed collagen peptides are absorbed more easily9 by your bloodstream and body than normal sized collagen molecules.*
“Hydrolyzed collagen is predigested so it does not go through that first-pass digestion in the GI tract,” says board-certified dermatologist Joshua Zeichner, M.D. “The collagen fragments can be absorbed as-is and circulate throughout the body to exert their effects.”*
Supports skin hydration.*
Clinical studies on collagen supplementation and skin hydration show that with regular use, it supports your skin's hydration levels.* For example, one double-blind, randomized, placebo-controlled clinical trial found that participants' moisture levels in the skin were seven times higher10 than those who did not take collagen supplements.*
It smooths the appearance of fine lines.*
Likely due to a combination of the above factors, clinical research has shown that collagen can support skin elasticity11 and potentially make fine lines appear smaller.* One double-blind, randomized, placebo-controlled clinical trial found that when a small group of women took a collagen supplement that was also formulated with hyaluronic acid and a few other actives, they experienced significantly smoother appearance of wrinkles.*
Benefits for hair and nails.
While the benefits on the hair are not as widely studied as of yet, collagen might help hair health in a few key ways:
It provides essential ingredients for hair.*
Hair is mainly made up of the protein keratin and structural lipids12. “Amino acids are the building blocks for keratin, the material that hair is made of,” Zeichner explains. Yes, for the body to build keratin, it needs several types of amino acids, many of which are found in collagen peptides13. In fact, the main amino acid in keratin is proline—which is readily found in many collagen supplements. The theory follows that if you ingest these amino acids, they can help support your natural levels of these essential compounds.*
It may support scalp health.*
Your scalp, we often forget, is simply your skin, just with more hair follicles. And thus what is beneficial to your skin—ahem, collagen—is beneficial to your scalp.* Research has shown time again that a damaged scalp leads to hair issues, like thinning and brittleness.
It supports nail health, reducing brittleness.*
In addition to promoting healthy hair, skin and nail growth, collagen supports joint and bone health and even helps promote digestive health and the gut microbiota that reside there.*
Supports gut and digestion health.*
One of the reasons collagen supplements have become so widespread are the potential gut health benefits.* While this is a newer area of study for collagen supplements, research has found that levels of certain types of collagen are lower in individuals with digestive challenges15.*
Additionally, research has found that one of the main amino acids in collagen, L-glutamate, supports the intestine by neutralizing oxidative stress16 and acts as a major fuel source for the cells in the intestine.* The cells of our gut lining also use proline and glycine for energy, and these are two additional amino acids found in collagen.*
Nurtures joint & bone health.*
Collagen type II is a common structural component of our joints. One randomized clinical trial found that people who took a type II collagen supplement for 180 days experienced improvements in their physical function and helped improve joint mobility and comfort.* Another recent study showed that when athletes who previously suffered joint injuries regularly took collagen, their overall joint health was supported17.*
As for bone health, it's a more time-intensive benefit to track—simply given how long the bone turnover timeline is—however, this clinical trial found that postmenopausal women had enhanced bone density18 at 12 months after consuming collagen peptides daily for a year.*
Contributes to muscle growth.*
Now as we’ve noted, collagen is not technically a complete protein—but it still delivers plenty of amino acids that can contribute to muscle mass.* This is especially true when combined with the right fitness routines. In one small clinical study, men who took collagen daily while participating in an exercise program gained more muscle mass19 than those who only completed the exercise program.*
Sources of collagen supplements: marine vs bovine.
Collagen supplements are derived from animal sources like bovine, marine, and poultry (chicken and eggshells). You can find “vegan” collagen, however, it’s important to clarify that those products don’t actually contain collagen itself—instead, they are simply nutrients and bioactives to help you produce or maintain your natural collagen levels.*
The two most common types of actual collagen on the market are bovine and marine. For the most health benefits, look for a grass-fed bovine collagen supplement, which contains collagen types I and III20, the types of collagen that are widespread in the human collagen network and, thus, vital in promoting overall health.* If that's not an option for your dietary approach, marine collagen is ideal for a pescatrian diet.
1. Grass-fed bovine
Bovine collagen is present in the connective tissue, bones, cartilage, and hides of cows. The collagen from cattle happens to be similar to the collagen we have in our own bodies.
Always seek out a bovine collagen supplement from an established company that sources their product from humanely raised, grass-fed and pasture-raised cows. And as with any supplement, only use those that have been tested for safety and quality.
Other ingredients to look for:
Many collagen supplements contain only collagen. But some take a more holistic approach, including synergistic and complementary nutrients and bioactives.* Here's why a few common ones are added to your collagen powder:
Vitamins C & E
Vitamin C plays an essential role in collagen production22, and is a vital molecule for skin health.* It is included in collagen supplements to give your body's natural collagen production additional intrinsic support.* Vitamin E is an essential fat-soluble vitamin important for normal collagen cross-linking.
We’d be remiss to not mention their antioxidant properties as well. Sun exposure, aging, and other sources of oxidative stress increase the need for antioxidants. Vitamins C and E are well-known antioxidant nutrients that scavenge free radicals and combat oxidative stress to help maintain healthy skin and gut health, while promoting overall healthy aging.*
Hyaluronic acid (HA) is another molecule found in the skin that works to keep it plump and well hydrated.* While it’s certainly most famous for its skin benefits, the molecule also keeps joints and other tissues well lubricated. Unfortunately, as with collagen, its production decreases as you age. Ingestible forms of HA have been shown to support skin hydration23.*
Biotin is an essential water-soluble B vitamin—vitamin B7, specifically. Research shows that if you have low levels of biotin, it can actually lead to hair shedding24. (Biotin deficiency is rare in the US population, however.)
Biotin is thought to support healthy hair growth because it is involved in the production of keratin, the main component of hair.* In one small study, women reported hair growth when supplementing with biotin as compared to those given a placebo.*
Turmeric & SGS
To round out a smart collagen supplement, you may look for options with antioxidant and anti-inflammatory actions. Take, for example, turmeric root and sulforaphane glucosinolate (SGS), unique botanicals loaded with phytonutrients with known antioxidant and anti-inflammatory properties.*
In the body, they are multitaskers, supporting detoxification, combating oxidative stress, and helping protect the skin from photoaging and supporting a healthy gut.* Turmeric is a botanical root loaded with curcuminoids, including the famous one, curcumin. And SGS is a phytochemical found in cruciferous vegetables like broccoli.*
What to look for in a collagen supplement.
We do a pretty thorough deep dive into finding the best collagen supplements on the market (including our favorites!), but as a quick recap here are some stand-out points that signify said collagen powder is top-notch.
We’ll explain more on this topic in the sections below—collagen dosage can get quite nuanced, so it’s worth a bigger explainer—but we recommend looking for a supplement that has 10 to 20 grams per serving. Collagen powders are the best delivery format for packing in these higher doses.
If you are looking for other benefits besides collagen-related ones, you can consider options with a lower range. Just be sure that the supplement of choice is buffered with other ingredients—otherwise, the option may be simply fluff. For example, some beauty supplements only have 13 grams of collagen; it’s not ideal, but fine if the other bioactives contribute to healthy aging.*
Look for brands that describe in detail where their collagen is sourced from (the animal, the country or region, etc.), be it on the packaging or website. Buzzwords like "grass-fed, pasture-raised bovine collagen," or "sustainably, wild-caught cod" are all good signs. Ideally, they'll also note what collagen types (type I, II, or III), as well as the amino acid profile.
Powders are the best, as they are able to deliver the most potent amount of collagen and blend easily into a wide variety of drinks and dishes. However, collagen does come in other formats—pills, tonics, drinks, gummies, and so on—if that’s more your thing.
As with most things we recommend, make sure the formula is clean. Less is more here: Skip artificial colors, sweeteners, and flavors, as well as fillers, chemical preservatives, gluten, GMOs, soy, and other known food allergens. If your collagen product is flavored, look for natural and responsibly-sourced varieties (such as organic cocoa and organic vanilla). If there's a sweetener, we recommend things like organic monk fruit extract or organic coconut sugar.
How long does it take for collagen to work?
The time frame for expecting results from your collagen supplements is entirely dependent on your desired outcome and health support focus area.* “Results” means something entirely different for the bones than it does for the gut or skin.
So having said that, here’s a mini overview of the amount of time clinical research suggests it takes to see benefits.* If you want more information—complete with research studies and expert advice—read our guide on collagen results.
- Skin support benefits: 4 to 12 weeks (1 to 3 months)
- Muscle mass and strength (combined with resistance training): 3 months
- Less soreness after physical training: within a few days
- Joint health support: 4 to 6 months
- Tendon support (combined with strengthening exercise): 3 to 6 months
- Bone-density support: 12 months
- Hair: unclear
- Nails: 6 months
How much collagen do you need each day?
Let’s talk dosage (in fact, we wrote a whole article on it!). Now unlike with some other vitamins, minerals, and supplements, the science is relatively young for collagen peptides. Read: while you may find definitive recommendations on intake levels (like a Recommended Daily Allowance, or RDA) and status blood biomarkers for things like vitamin D, with specific needs depending on your age, sex, dietary pattern, and lifestyle, it's just not the same for collagen at this time (yet).
But in general: For healthy adults, the recommendation for overall protein needs is about 1 gram of protein per kilogram of body weight per day. If you're physically active, your needs may be higher.
Collagen is a protein made of peptides, but you’ll recall that we shared, it's not a complete protein—it doesn't have all nine of the essential amino acids (it's missing tryptophan and is on the lower side on a few others)—but can certainly still contribute to your overall protein goals on a daily basis.* For a collagen supplement, we recommend looking in the 10- to 20-gram range.
If you want to get more specific, it’s helpful to look at your intended need for the supplement. Here, a breakdown based on outcome.
- Skin: Studies show that a range of 2.5 to 10 grams per day can be beneficial for skin support6.*
- Muscle: Studies show that 15 to 20 grams per day can help muscle mass25, muscle strength26, and soreness after exercise27.*
- Joint: 2.5 to 5 grams per day has been shown to help joint support28—however, if you are taking UC-II specifically, you only need 40 milligrams per day29.*
- Bone: The available research suggests that 5 grams per day provides bone support18.*
Do topical collagen products work?
Topical versions of collagen—like creams and serums—can be effective moisturizers, but that’s it. The collagen molecule is too large to penetrate well enough to access the deeper layers of the skin.
"Collagen is a huge molecule that sits on the surface of the skin and cannot be absorbed into the dermis," board-certified dermatologist Dendy Engelman, M.D., says. "When applied topically, it is not possible for collagen to penetrate, which is why we use other actives to stimulate collagen production." She confirms that any topical product that claims benefits is simply a marketing tactic.
Oral forms, by contrast, are broken down and designed to be absorbed through the intestine into the bloodstream, and then onto cells and tissues throughout the body. From there it can increase the body's natural collagen production, so it can fortify and build collagen at the dermal layer.
Plus, oral supplementation helps to deliver specific amino acids, which are considered the critical building blocks, the architectural scaffolding, of collagen synthesis. This can only be achieved through oral supplementation.*
Adding a collagen supplement to your diet can offer a host of benefits that include health support for skin, hair, nails, the gut, joints, bones, and muscles.* Grass-fed bovine collagen contains the essential collagen types I and III for the most full-body benefits.* Collagen supplements that include other nutrients (biotin, vitamin C, vitamin E) and bioactives (think: hyaluronic acid, L-glutamine, turmeric, SGS) to support hair, skin, and gut health in a comprehensive way will only up the benefits.*
Alexandra Engler is the beauty director at mindbodygreen and host of the beauty podcast Clean Beauty School. Previously, she's held beauty roles at Harper's Bazaar, Marie Claire, SELF, and Cosmopolitan; her byline has appeared in Esquire, Sports Illustrated, and Allure.com. In her current role, she covers all the latest trends in the clean and natural beauty space, as well as lifestyle topics, such as travel. She received her journalism degree from Marquette University, graduating first in the department. She lives in Brooklyn, New York.