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The Potential Downsides Of Collagen Supplements


By now, the health benefits of collagen supplements are pretty well understood. Collagen, which is the most abundant protein in your body and the primary component of your connective tissue, is crucial for your body’s structure and function.


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Research shows that adding collagen to your supplement routine can promote skin elasticity and skin hydration, relieve joint pain, enhance bone health, and support your digestive tract[*][*][*][*].

What most people don’t talk about, however, is the potential side effects of collagen supplementation. Are there side effects to taking collagen? And, if so, are they serious?

Potential Pitfalls Of Collagen Supplements

Most people find collagen to be well-tolerated with little to no side effects. With that being said, there are some potential drawbacks to collagen that you may want to be aware of before you incorporate this supplement into your daily regimen.

#1 Digestive Disturbance

Some people report that taking collagen results in bloating or a heaviness in their stomachs. Excessive protein consumption can be hard on your digestion and may result in constipation or diarrhea if you don’t have the digestive strength to properly process it[*].

Eating more fiber and staying on top of your hydration can assist in your digestive process, so if you find that collagen gives you trouble with digestion, try increasing your water and fiber intake before throwing the towel in altogether[*][*].

#2 Allergies

Collagen powders can be made from a variety of sources, including bovine, fish, shellfish, and eggs. Not many people experience allergic reactions to bovine (cows), but shellfish and egg allergies are much more common.

If you have food sensitivities or allergies be extra careful to check the source of collagen in your supplement.

Some collagen powders may be manufactured in facilities that also process ingredients like wheat, soy, and tree nuts, so be sure that you scrutinize the label if you have any of those common allergies.

#3 Collagen is Not a Complete Protein

Collagen is a source of protein, but it is not a complete source of protein. In order for a food or dietary supplement to be considered a complete protein, it must contain all of the essential amino acids in the proper ratio. Unfortunately, collagen is low in one of the essential amino acids, tryptophan[*].

Tryptophan is a precursor to the neurotransmitter serotonin, which is related to the regulation of mood and emotional states. Serotonin deficiency is linked to depression and other psychological disorders[*].

Not to worry, you can still get the benefits of collagen — just be sure to incorporate other sources of protein, like a whey protein shake or plenty of grass-fed organic meat and wild-caught fish.

#4 Drug and Supplement Interactions

Since collagen is not a whole food, there is always potential for it to interact with medications and other supplements. Although this is relatively uncommon, research shows that collagen may interfere with some medications and over the counter supplements[*].

Again, you might want to check with your healthcare provider before starting a new supplement regimen.

#5 Bad Taste

Some people complain of a bad aftertaste with some collagen powders. Although this doesn’t pose any significant health threat, it can be rather unpleasant and a bit of a turnoff for some people[*].

Choosing a high-quality, grass-fed flavored collagen or mixing your collagen into a smoothie is a great way to mask any unpleasant tastes that could be left behind from drinking collagen powders.

#6 Low-Quality Ingredients

Many collagen powders come with additional ingredients like preservatives, flavors, and fillers. Always check your ingredient label to make sure that the ingredients included in your supplement are high-quality.

For instance, if you want chocolate-flavored collagen, look for “cocoa powder” as opposed to “chocolate flavoring.”

Similarly, many brands will add sweeteners to enhance the flavor of their product. Look for natural sweeteners like monk fruit and stevia, and beware of artificial sweeteners like sucralose and aspartame, which may have neurotoxic effects[*].

What To Look For In A Collagen Supplement

There are now more collagen supplements on the market than ever before. On the one hand, this means that you get to choose from a variety of products to pick which one suits your personal needs. On the other hand, the abundance of options can make it more confusing to know which collagen supplement is the right one for you.

Below are the most important things to look for when deciding which collagen supplement to go with.


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#1 Hydrolyzed Collagen

Hydrolyzed collagen protein (or collagen peptides) is a form of collagen that’s already broken down into more easily digestible amino acids. As opposed to collagen or gelatin that hasn’t been hydrolyzed, collagen peptides are more bioavailable, meaning your body can absorb and utilize them more efficiently. Hydrolyzed collagen also enhances the powder’s antioxidant and antimicrobial activity[*].

Collagen supplements that are hydrolyzed will almost always include “hydrolyzed”, “collagen hydrolysate,” or “collagen peptides” on the ingredient label, so for optimal efficacy, always look for this form of collagen in your supplement.

#2 Clean Ingredients

Most collagen supplements come with other ingredients that enhance the flavor or help preserve the powder. In some cases, however, you may also get filler ingredients that add bulk to the powder but offer no other benefit.

This is why it’s always vital that you check the ingredient labels on your collagen powder supplement. Clean ingredients will go by names that you recognize, like “stevia” or “cocoa powder” or “vanilla extract.”

Look out for red-flag ingredients like maltodextrin (adds thickness and shelf life) and sucralose (artificial sweetener). In general, if you don’t recognize the word or can’t pronounce it, you should avoid it.

#3 Low- or No-Carb

Along with clean ingredients, you always want to double-check the nutrition facts and ingredient labels to make sure there aren’t any sneaky sources of carbs included in your supplement.

Collagen supplements should contain 0 to 3 grams of carbs per serving maximum. Anything more is unnecessary and may push you out of ketosis (depending on what else you include with your collagen beverage).

Watch out for ingredients like cane sugar, agave, high fructose corn syrup, brown rice syrup, cane crystals, sucrose, invert sugar, fructose, and dextrose.

#4 Good Manufacturing Processes

Admittedly, it can be hard to determine which companies are following good manufacturing processes and which are cutting corners.

Your best bet is to always go with a company you trust. Research conducted by the clean label project found that many of the collagen products on the market are contaminated with heavy metals like cadmium and lead at levels that exceed the safety limit[*].

If you’re concerned about what contaminants may be lurking in your collagen powder, choose a company that is transparent in their manufacturing process, and reach out to them directly with any concerns. If a company has nothing to hide, they will happily be forthright with any information you request, and many of them will provide evidence of third-party testing.

#5 Grass-Fed Bovine

There are many options when it comes to the source of your collagen supplement. However, bovine collagen is by far the most well-researched and scientifically proven type of collagen to impact human health, with several placebo-controlled scientific research papers backing it up[*][*][*].

With that being said, not all bovine collagen is created equal. Choosing grass-fed bovine collagen ensures that the animal was fed a diet suited for its digestion, which results in a happy and healthy cow.

Furthermore, factory-farmed animals are frequently given hormones and antibiotics and are fed a diet that may be contaminated with heavy metals and pesticides. They’re also fed GMO crops like corn and soy, which are not only unhealthy for the animal, but these crops are treated with synthetic fertilizers that contain dangerous compounds[*].

#6 10 Grams Of Collagen Per Serving

Most studies show that 10 grams of collagen per serving is an effective dose for positive outcomes. You may see collagen supplements on the market that claim to have twice as many servings as other brands, but the serving size is around 5 grams or less.

Always check serving size on your collagen supplement, especially when you’re comparing price points. A large number of servings doesn’t mean much if there’s less collagen per serving.

The Takeaway

If you’re seeking a supplement that can support wellness on multiple levels, collagen supplements offer a range of benefits that have been backed by clinical trials.

Bone mineral density, joint health, gut health, and skincare, have all been topics of interest regarding collagen and its ability to support human health.


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However, as is true with most supplements on the market, collagen also comes with its potential downsides. While the beneficial effects still outweigh the potential side effects for most people, you can never go wrong by staying aware of what to look for and what to avoid when choosing supplements to add to your healthcare routine.

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