Collagen: Benefits, Types, Food Sources, Dosage & Side Effects

Dr. Josh Axe Vitamin Advisor · 4–5 questions

Is collagen one of your top 5?

What's your biggest goal right now?

Immunity & getting sickEnergy & fatigueGut & digestionSleep & stressHormones & thyroidJoints & inflammationBlood sugar & weightBrain, focus & moodHeart healthSkin

Collagen is the main structural protein in your body. It gives skin its firmness and tendons their pull, and it forms the framework your bones are built on.17 I describe it as the scaffolding of your body, the glue that holds everything together and keeps it from sagging.8

You make collagen every day from the amino acids you eat, mainly glycine, proline and hydroxyproline, and the richest sources are the parts of the animal modern diets throw away.9 My approach starts in the kitchen. Bone broth comes first, chicken broth in particular, because along with its collagen it brings chondroitin and hyaluronic acid.810 After broth come skin-on fish and chicken, then bovine or fish gelatin and collagen peptides.

Collagen also sits at the center of my approach to rebuilding the gut lining,2 and it supports your joints, skin, bones and muscles too.

Did you know?

• Collagen is a family of 28 proteins, and every one of them contains at least one triple helix, three protein strands wound around each other.11

• Collagen accounts for about three-quarters of the dry weight of your skin.1

• About 90% of the organic part of your bones is collagen, the framework the minerals are laid into.7

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What is collagen?

Collagen is the scaffolding in the extracellular matrix, the material between your cells: it gives tissues their shape and strength and gives cells something to attach to, move along and multiply on.11 Its three strands are built on a repeating pattern in which glycine sits at every third position, with proline and hydroxyproline packed in between.11

Types of collagen and where they're found in your body

Of the 28 types, five come up again and again, and three do most of the work you'd notice: type I, type II and type III.111

The section on which type is best, further down, covers what this means for choosing a supplement.

A short history of bone broth

For most of history, people got their collagen from the pot. In Ancient Remedies, I describe bone broth, simmered from the bones and ligaments of beef, chicken, fish and lamb, as "a staple for our ancestors, who used every part of an animal as sustenance."12 Gastroenterologists at Mayo Clinic open their 2025 review of broth the same way, calling it a traditional remedy revered by different peoples from ancient times to today.13 Collagen powders are a modern convenience built on that old habit.

Why does your body make less collagen as you age?

Your collagen declines year by year as you get older, and on my show I've described how that shows up as more wrinkles, joint pain, digestive issues and slower recovery.8 Skin collagen content falls by roughly 1% a year through adult life, a figure researchers trace to a 1975 study of forearm skin in a large group of adults.1415 The cells that make collagen slow down too: skin cells from people over 80 made about a third less type I procollagen, collagen's starting material, than cells from people aged 18 to 29.16

Beyond age, several everyday drivers speed the loss, and most of them are yours to change:

• Menopause. In 76 women aged 20 to 60, skin collagen dropped significantly after the 40s and again after menopause, in step with bone density.17 Our guide to menopause supplements and diet covers the natural steps.

• Smoking. In a study of 47 smokers and 51 people who had never smoked, smokers' skin made 18% less type I collagen and 22% less type III.18 Here's how to start quitting smoking.

• Sunburn. UV light raises MMP-1, the enzyme that starts most of the collagen breakdown UV causes in skin.19 Get your sunshine in sensible doses, and don't burn.

• Sugar. On my show, I've explained that a high-sugar diet speeds collagen breakdown through compounds called advanced glycation end products, or AGEs.20 See the foods that damage collagen.

Feeding your collagen matters as much as protecting it. Alongside collagen, I tell people to get plenty of zinc, copper and vitamin C.20 Vitamin C has the clearest research: healthy skin holds high levels of it, and it stimulates collagen production.21

Collagen nutrition facts

Values from USDA FoodData Central, FDC ID 169599 (gelatin, dry powder, unsweetened). Per-serving amounts are calculated from the per-100-gram values, using USDA's 7-gram envelope.22

Glycine leads the amino acids in the record at 19 grams per 100, followed by proline,22 so a scoop of collagen delivers a concentrated dose of both, the raw materials your body uses to make its own collagen.9 Twenty grams of gelatin supplies about 17 grams of protein.22

Is collagen a complete protein?

No. Collagen has no tryptophan, one of the nine essential amino acids, so it counts as an incomplete protein.2322 It still fits comfortably in a healthy diet: a modeling study found that collagen peptides could supply up to 36% of the protein in a typical Western diet while every essential amino acid need was still met.23 Eat collagen alongside complete proteins such as eggs, fish and poultry, and see how many grams of protein a day you need in total.

What is collagen good for?

How does collagen work in your body?

Here's what happens when you eat collagen: digestion breaks most of it down, but some survives as tiny pieces just two or three amino acids long that reach your blood and signal the cells that build new collagen.

Researchers propose that this signaling explains much of what the skin and joint trials measured.36 Collagen from fish and cattle is absorbed well: in a study in which 6 healthy adults each tried hydrolysates from several sources, both fish collagen and bovine collagen produced meaningful blood levels of these peptides.38

What are the benefits of collagen?

Gut repair leads this list because collagen and bone broth are at the center of my gut-healing protocol. Then come joint pain, skin, bone density, muscle, sleep and hair and nails.

Can collagen help heal your gut?

Healing the gut starts with taking away what irritates it and then rebuilding the lining. My gut-healing protocol follows six steps in order, the 6R plan: Remove, Replace, Reinoculate, Repair, Rebalance and Reframe. Collagen peptides are among the essential supplements of the Repair phase, taken alongside bone broth every day.2 In Heal Your Cells, Dr. Will Cole and I recommend amino acid–rich foods to heal the intestinal lining, naming bone broth, collagen and gelatin (bovine or fish), because they "support the tight junctions that prevent nutrient loss and inflammation."9 On my show, I've put it simply: collagen peptides give your body what it needs to rebuild the gut.44

A 2025 review by Mayo Clinic gastroenterologists lays out the case for broth. Bone broth supplies glutamine, glycine, proline, histidine and arginine, plus calcium, phosphorus, potassium, magnesium and zinc, and the reviewers found that the documented benefits of these nutrients support gut health, calm inflammation in the intestinal barrier and improve barrier function, especially in inflammatory bowel disease. They present broth as a potential remedy, particularly for keeping conditions like IBD in remission.13

Lab and animal studies show the same direction:

People report the difference too. In an 8-week study without a placebo group, 40 healthy women with a BMI over 25 started on 20 grams of collagen peptides a day, split into two doses, and 14 finished; 13 of those 14 reported fewer digestive symptoms, including bloating.3 In a week-long trial in which 20 trained volunteers each tried 10 grams of collagen peptides a day and a placebo before a hard run, gut permeability didn't differ between the two, but LPS, a toxin from gut bacteria that can leak into the blood, rose after the run only on placebo.46

To put collagen to work for your gut, start the free Healing Leaky Gut protocol, which builds collagen and bone broth into the Repair step of its 30-day plan, and see our guides to leaky gut, the leaky gut diet and L-glutamine.

Bone broth, gelatin or collagen peptides: which form is best?

Every form delivers collagen; they differ in how much you get, how they dissolve and what comes along with them. For a closer look at two of them, see collagen vs. bone broth.

Is gelatin as good as collagen peptides?

Bovine or fish gelatin belongs right beside collagen peptides, because they carry the same amino acids.479 Gelatin has its own human research. In a study in which 8 healthy young men each tried three drinks before 6 minutes of rope-skipping, three times a day for 3 days, 15 grams of gelatin taken an hour beforehand doubled a blood marker of new collagen formation: PINP rose 153% at 4 hours, against 59.2% after 5 grams of gelatin and 53.9% after the placebo. All three drinks were mixed into the same vitamin C–rich concentrate.50

The practical difference is texture. Collagen peptides stir into cold drinks and coffee without clumping, which makes them easy to take every day; bovine or fish gelatin works best in warm broth, soups and homemade gummies. See collagen vs. gelatin for a side-by-side comparison.

Which type of collagen is best?

Type I is the collagen of your skin, bones and tendons, the type that forms every fibrous tissue except cartilage.1 The animal source matters less than you might expect: in the 26-trial skin analysis, collagen from different sources improved elasticity with no significant difference between them.5 For cartilage, undenatured type II collagen is its own category, described above.

The best source is the one your body tolerates. If you have a fish or red meat (alpha-gal) allergy, read the safety section before choosing a source. Our guides to bovine collagen, fish collagen, chicken collagen and the types of collagen go deeper.

How to choose a collagen supplement

• Source named: bovine (look for grass-fed or pasture-raised) or fish (look for wild-caught)

• Grams of collagen per scoop printed on the label, so you can count it toward your daily amount

• Third-party tested for purity and heavy metals, since the FDA doesn't review supplements for safety or effectiveness before they're sold51

• Unflavored, with no added sugar; if you want it sweeter, add a little raw honey at home

• Bovine or fish on any gelatin you buy

What foods are high in collagen?

I tell people to eat the skin on their fish and chicken, because when you eat the skin, you're getting loads of collagen.5253 In a Japanese study of everyday dishes, the meat in one serving of most dishes held 0.2 to 2.5 grams of collagen, and when volunteers ate cooked fish, nine kinds of the small collagen pieces that supplements deliver showed up in their blood.54 Food builds the foundation, and a scoop of bovine or fish gelatin or collagen peptides gives you a measured amount on top.

• Bone broth, chicken first, plus beef, lamb and fish bones.12 Find more ideas in our bone broth recipes.

• Skin-on fish, such as wild-caught salmon and the other fish in our guide to the best fish to eat.

• Skin-on chicken, roasted or simmered with the bones and cartilage for broth.

• Bovine or fish gelatin, stirred into broth and soups or set into gummies.

• Collagen peptides, stirred into coffee, smoothies or soups.

How much collagen should you take a day?

My daily target sits at the high end of what's been studied, and there's support for aiming high. In a study in which 10 resistance-trained men each tried three doses an hour before a squat workout, 30 grams of hydrolyzed collagen raised a blood marker of collagen formation more than 15 grams or none.55

Bone broth counts toward that total, and how much it supplies depends on the pot: in a lab analysis, broth made to a standard recipe carried less glycine, proline and hydroxyproline than a 20-gram serving of collagen supplement, and broths made to different recipes varied widely.56 A mug of broth plus a scoop of collagen peptides or bovine or fish gelatin is an easy way to reach the amounts used in the trials. Our guide to how much bone broth to drink daily has more.

When is the best time to take collagen?

There's no single best time, so pick the one that fits your goal. For sleep, take it about an hour before bed, the timing used in the sleep trial.31 Around training, take it about an hour before you exercise along with a source of vitamin C, the approach used in the gelatin and dose studies.5055 For everything else, take it whenever you'll remember it, in your morning coffee or a bowl of soup.

How to use collagen every day

Bone broth and bovine or fish gelatin fit into the meals you already make, and unflavored collagen peptides mix into almost anything.

Collagen side effects and who should be careful

The skin research agrees: a 2026 review of 25 trials found hydrolyzed collagen generally well tolerated, with a low rate of side effects.26 Medicine works best when it's personal, so these are the situations where the source or the amount should change:

• Fish allergy. Anaphylaxis has been reported after hydrolyzed fish collagen and after marshmallows made with fish gelatin.5758 If you're allergic to fish, skip fish collagen and fish gelatin and choose bovine.

• Red meat (alpha-gal) allergy. In an allergy clinic that tested 1,335 adults, 30 of the 40 with red meat allergy tested positive for gelatin and 12 were allergic to it, and the alpha-gal sugar was found in bovine gelatin.59 If you have alpha-gal syndrome, skip bovine gelatin and bovine collagen, and choose any source with your allergist.

• Calcium oxalate kidney stones. Your body can turn hydroxyproline, an amino acid in collagen, into oxalate. In 10 healthy adults, 30 grams of gelatin a day for 5 days raised urinary oxalate 43% compared with the same amount of whey protein, and single doses of 5 and 10 grams raised it while 1 and 2 grams didn't.60 If you've had kidney stones, keep collagen and gelatin to modest amounts and set your dose with your practitioner.

• Kidney disease with a protein limit. Collagen is concentrated protein, about 6 grams in a 7-gram envelope of gelatin, so count it toward your daily limit.22

• Pregnancy and nursing. None of the trials on this page enrolled pregnant or nursing women. Broth and collagen-rich foods are everyday foods; if you want a collagen supplement during pregnancy, confirm the dose with your OB.

• Lead in broth. One lab study found lead and cadmium in broth at only a few micrograms per serving and judged the risk minimal, while a small test of organic chicken broths found several times the lead of the water they were made with.6162 Make broth from the bones of well-raised animals, and buy powders tested by an independent lab.

The bottom line

Collagen: frequently asked questions

References

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