Collagen has become a popular supplement over the past several years and claims to offer a ton of health benefits which can be reason for skepticism since most new supplements that make big claims or promises are typically overstated. However collagen may be different, especially in the context of pregnancy.

Glycine makes up about one third of the collagen structure and collagen makes up about one third of your total body protein! 

During pregnancy the amino acid glycine becomes essential meaning our bodies cannot make enough to keep up with demand. Outside of pregnancy, it is considered “conditionally essential”. 

Glycine is important for both mamas and developing babies. More details to come on glycine’s role but baby’s DNA, bones, organs, blood vessels, and connective tissue require lots of glycine. Remember all of these structures are being formed in their entirety! 

Mama needs glycine for her changing uterus, the growth of an entire new organ (the placenta), her adjusting skin, the liver to detox properly, and to help her maintain a normal blood pressure. 

Glycine is found in highest concentrations in animal connective tissue. As vegan and vegetarian diets gain popularity, glycine is a nutrient many people are lacking in their regular diet.

Those who do eat animal products tend to choose cuts of meat with low connective tissue and thus are low in collagen. We like steaks, chops, loin cuts, and breasts instead of roasts. Roasts need to be cooked via low temperature for longer periods of time because of their higher connective tissue content. 

These cuts of meat with higher connective tissue like roasts, briskets, pork shoulders, etc. also tend to be less expensive, which is a win-win situation! Start buying and eating more roasts! 

Bone, skin, ligaments, tendons, and organs is where the most collagen can be found because of their high connective tissue content. Compared to how people ate just several generations back, we eat very little connective tissue. 

We like our meat skinless and boneless meaning we’re missing out on a ton of collagen and glycine! 

Collagen is a fantastic source of glycine. That makes sense if you know a little about anatomy because the connective tissues of animals are made primarily of collagen and collagen is where the glycine is! 

Glycine is the main amino acid we’re really after with collagen. However, other amino acids are found in significant amounts in collagen including proline.

Proline is an often overlooked amino acid that plays a major role in pregnancy. Proline is involved in the process of cells changing from one type to another, including stem cells and it is vital to fetal growth.

Importance of Glycine


  • Liver detoxification and formation of glutathione
    • Glutathione is one of the most important antioxidants in the body and glycine is essential to form glutathione. Glutathione helps protect your cells from free radical (oxidative) damage.
  • Maintain healthy blood pressure and reduce preeclampsia risk
    • Glycine is involved in the cardiovascular system partly because of its role in the production of elastin which is necessary for blood vessel structure. Elastin keeps the blood vessels flexible.
    • Glycine is also protective against oxidative damage (as noted above) which is a hallmark of preeclampsia.
  • Skin
    • A pregnant woman’s skin has to stretch to a large degree and glycine plays an important role in that process. Glycine intake may play a significant role in risk of stretch marks.
    • A topic of concern for many pregnant women is the perineum tearing during delivery. Skin being able to stretch adequately is an important part of preventing such tearing. If tearing does happen, glycine is important to help properly heal.
  • Uterus
    • The uterus at the end of pregnancy contains 800% collagen compared to before pregnancy! Not only is your skin stretching to make room for baby, so is your uterus. The uterus goes through many physical changes during pregnancy and collagen is a big part of that.
  • Joints
    • Our joints are composed of ligaments, tendons, and connective tissue. All of these structures have a large collagen content. Joints are put under a higher degree of stress during pregnancy due to center of gravity changes and increased body weight during pregnancy. Collagen and glycine can help keep those joints healthy.
  • Methylation
    • Methylation has been getting a lot of attention recently but simply put, it is a biochemical process that is crucial for maintaining overall health. It regulates gene expression and is part of the epigenetics system. Glycine plays an implant role in that process along with folate, choline, and vitamin B12.


  • Feta DNA
    • Because glycine is involved in the methylation process, it is necessary for the formation of baby’s DNA!
  • Bones, teeth, connective tissue, organ, and blood vessel formation
    • All of these structures that are being formed need a lot of glycine!

Collagen for Postpartum

The importance of collagen continues postpartum. All of the structures that adapted during pregnancy have to adapt once again to a nonpregnant state. 

Glycine and proline (two of the amino acids high in collagen) are required for tissue healing. Even if you had an uncomplicated delivery, you still have tissues that require a lot of healing. If you had a cesarean section, the healing that is required is even higher. 

Collagen encourages the belly skin to regain elasticity and the uterus to return to prepregnancy size. 

Sources of Glycine

The best way to get glycine or collagen is from the diet using whole foods. Eat the connective tissue, skin, and bones of animals. This isn’t too challenging but may take some adjusting of your current behaviors. 

  • Poultry with the skin on
    • 3 oz roasted whole chicken with skin on contains 2.8g glycine
  • Slow cooked tougher cuts of meat like roasts because these contain more connective tissue, hence why they are tougher
    • 3 oz cooked chuck roast contains 1.5g glycine
  • Bone broth
    • Glycine content will depend on cooking methods and types of bones used. Use hooves, feet, and heads in your broth making to boost the glycine content. For beef broth it is best to use marrow and knuckle bones. For chicken broth, use the entire chicken carcass boney parts.
  • Pork rinds or cracklings
    • 1 oz plain pork rinds contains 3.4g glycine
  • Sausage links in natural casing
  • Fish with bones such as sardines
    • 3.5 oz sardines with bones contain 1.2g glycine
  • Collagen or gelatin powder supplements
    • 15g of collagen contains about 3g glycine depending on type and brand
  • Homemade Gummy Snacks

You’ll notice that all of these are animal products. Even the supplements are made from animals. Eating a vegan or vegetarian diet will lead to insufficents glycine intake. However, there are some plant sources of glycine.

Vegan sources of glycine

  • Sesame seed flour (1.94g per ½ cup)
  • Dried spirulina (1.76g per ½ cup or 2oz)
  • Black beans (280mg per ½ cup)

Collagen works with vitamin C to form collagen structures so don’t forget to eat fresh raw fruits and vegetables to satisfy your vitamin C requirements. 

Best Collagen Supplements for Pregnancy

While food is best, supplements can certainly fill in gaps where our diet may be lacking or act as a sort of insurance policy. Collagen supplements are fairly inexpensive and there is very little downside or risk. 

The one risk with collagen supplements or any supplements is the risk of contamination with things like heavy metals. During pregnancy, you may find that risk isn’t worth it. However, there are some things you can do to mitigate that risk such as asking brands for their heavy metal testing results. They should be readily available and willing to share. You can also choose brands that are GMP certified. 

Here is my favrotie collagen brand. If you’re getting any of those high collagen foods regularly, try to get at least half of a serving of collagen powder daily. However, if you get very little meat or other higher collagen foods aim for at least the full serving daily.

The nice thing about collagen is that it readily dissolves in liquid. It will dissolve in cold or hot liquids though I find I do notice a texture change when mixed in cold liquids. 

My favorite way to use collagen supplements is in hot tea or mixed in smoothies. You can also add it to soups, oatmeal, or use it in baking. 

Collagen versus Gelatin

Gelatin is a cooked, partially degraded form of collagen and dissolves only in hot liquid. Collagen and gelatin have the same amino acid and nutrition profile. Both contain high amounts of glycine. 

Collagen and/or gelatin can be used to increase your glycine intake. Gelatin will solidify once heated and cooled. You can use gelatin powders or sheets to make gelatin snacks and eat those to increase your glycine intake. 

What you’re actually getting in bone broth is more gelatin than collagen. You may notice that your bone broth solidifies slightly when in the fridge. This is a good thing! 

Collagen Protein Content

While many of the high collagen foods listed above can be great sources of collagen and protein in general, I would not use a gelatin or collagen supplement as your main protein source for a meal. 

Yes, collagen is protein but it is very low in the amino acid leucine. Leucine is needed to “turn on” muscle protein synthesis, the muscle building process. Even if you’re not a bodybuilder, this process is critical to health. Because collagen is a poor source of leucine it cannot “turn on” that muscle building and repair process by itself.

Add another protein source to that meal instead. Making a smoothie as a meal? Add the collagen powder but also add  whey, egg white, beef, or plant based protein powder. Putting collagen powder in your soup? Also add some meat or lentils and beans to that soup. 


Here are some practical take-aways to start incorporating into your behaviors

  • Eat foods high in collagen and glycine: poultry with the skin on, roasts and tougher cuts of meat cooked low and slow, pork rinds, and sausage links in natural casing. Get your animal products from local, pastured raised sources when possible.
  • Drink bone broth or use it in cooking. Use bone broth as your liquid for soups and stews but also use it to cook rice, dried beans, etc. Make bone broth at home when possible. Or purchace from a quaility source.
  • Take a collagen or gelatin supplement as an insurance policy to meet the 10g glycine per day recommendation.

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