Collagen powder is one of the most popular supplements around. So the question of whether collagen can have side effects comes up often. The short answer: collagen is considered well tolerated. It is not entirely free of possible complaints, though, and for some people a closer look is worthwhile.
In this article you will learn which side effects have been described, where they usually come from and how to recognise a well-tolerated collagen powder.
Does collagen have side effects?
Collagen is a protein, just like the protein found in meat, skin, bones and bone broth. In the gut it is broken down into amino acids and short peptides like any other dietary protein. As collagen hydrolysate it already comes in small pieces. We explain exactly what collagen hydrolysate is in the article What is hydrolysed collagen?.
In studies with collagen peptides, side effects were rarely reported, and when they were, they were mostly mild. The most common causes of complaints are a large amount at once, an intolerance to the animal source or additives in the product.
Digestion: fullness, bloating, heartburn
Occasionally people report a feeling of fullness, bloating or mild heartburn. This mainly happens when a large serving is taken on an empty stomach.
- Start with a smaller serving and increase slowly.
- Take collagen with a meal or in your morning coffee rather than on an empty stomach.
- If needed, split the daily amount into two servings.
Allergies: the source matters
Collagen always comes from animals. Depending on the product, that means cattle, fish, chicken or pork. Allergies to beef protein are rare but possible. If you are allergic to fish, avoid marine collagen. The label tells you where the collagen comes from. How the sources differ is explained in the article Bovine collagen.
Additives: the most common cause of complaints
Many collagen powders contain more than collagen: flavourings, sweeteners, sugar alcohols, thickeners or fillers. Sugar alcohols such as sorbitol or xylitol in particular can have a laxative effect if consumed in excess. If you are sensitive, a pure powder with no other ingredients is your best choice.
Who should take care?
- If you are prone to kidney stones: collagen contains a lot of hydroxyproline. The body converts part of it into oxalate. If you tend to form calcium oxalate stones, discuss regular use with your doctor.
- With kidney disease or a low-protein diet: collagen is protein and counts towards your daily protein intake.
- During pregnancy and breastfeeding: data is limited here. Talk to your doctor before taking it.
- If you take medication regularly: if in doubt, check briefly with your doctor whether anything speaks against it.
Can you take too much collagen?
Studies mostly used 2.5 to 15 grams of collagen per day. Stick to the recommended intake on the pack. Also important: collagen is not a complete protein because it lacks the amino acid tryptophan. It complements meat, eggs, dairy or whey but does not replace them. If you cover most of your protein needs with collagen, you get too little of the other essential amino acids.
As for calories: 10 grams of pure collagen powder provide just under 38 kcal. Weight gain from a normal serving is therefore hardly an issue.
How to spot a well-tolerated collagen powder
- The ingredient list names only collagen or collagen hydrolysate.
- The animal source and collagen types are clearly stated.
- It is hydrolysed and dissolves without lumps.
Our collagen powder consists only of type I and III collagen from grass-fed cattle raised on organic pasture farms, with no flavourings, sweeteners or fillers. What else to look for when buying is summarised in our guide Best collagen powder.
Conclusion
Collagen is considered well tolerated. If complaints occur, they mostly affect digestion and can be avoided with a smaller serving or by taking it with a meal. Additives are a more common trigger than the collagen itself. If you are prone to kidney stones, pregnant or take medication regularly, check with your doctor first. What research shows about the effects of collagen is covered in the article What is collagen good for?.
Frequently asked questions
Can collagen cause digestive problems?
Occasionally fullness, bloating or mild heartburn occur, mostly with large amounts on an empty stomach. A smaller serving with a meal usually helps.
Can you be allergic to collagen?
Yes, an allergy to the animal source is possible, for example to fish. Allergies to beef protein are rare.
How much collagen per day is too much?
Studies mostly used 2.5 to 15 grams per day. Stick to the recommended intake on the pack.
This article is for general information only and does not replace medical advice.