What Collagen Doesn't Cause Constipation? The Truth About Supplements

November 23, 2025 •

4 min read

A 2022 clinical study on collagen peptides found that 94% of participants experienced increased bowel movement frequency. Despite these benefits, many still wonder what collagen doesn't cause constipation, often due to high protein intake or inadequate fiber and hydration associated with supplementation.

Quick Summary

Collagen itself is not the typical cause of constipation. The issue often stems from the supplement's form, source, or user habits. Choosing highly digestible hydrolyzed collagen, increasing fiber and water intake, and being mindful of calcium content can prevent digestive discomfort.

Key Points

Hydrolyzed Collagen: This is the best form, as the broken-down peptides are easier to digest and less likely to cause issues.
Increase Hydration: Drinking plenty of water is crucial to prevent collagen from absorbing too much moisture from your intestines.
Pair with Fiber: Compensate for the high protein content by consuming fiber-rich foods like fruits and vegetables.
Check Calcium Levels: Bovine and poultry collagen are typically lower in calcium than some marine sources, making them preferable for those sensitive to calcium.
Start Slow: Begin with a low dose to allow your digestive system time to adjust, especially if you have a sensitive stomach.
Consider the Gut: Collagen can positively support gut health by aiding in digestion and healing the gut lining.

While it may seem counterintuitive, collagen does not inherently cause constipation. For many, it can actually aid in digestion and support a healthy gut lining. The key to avoiding digestive discomfort, including constipation, lies in understanding the different types of collagen, how your body processes them, and the importance of supporting factors like hydration and fiber intake.

Why Some Collagen Supplements Cause Digestive Issues

Constipation from collagen supplementation is not a side effect of the protein itself but rather a result of several contributing factors:

High Protein, Low Fiber: Many collagen supplements are pure protein with little to no fiber. Adding a significant amount of protein to your diet without increasing fiber can lead to harder stools and slower bowel movements. For a healthy digestive system, fiber is essential for adding bulk to stool and facilitating its passage.
Inadequate Hydration: Collagen is a hydrophilic molecule, meaning it attracts water. If you increase your collagen intake without also significantly increasing your water consumption, the collagen can pull moisture from your intestines, leading to dehydration and harder, more difficult-to-pass stools.
Source-Specific Calcium Content: Some collagen, particularly certain marine-sourced varieties (like shellfish or shark cartilage), can contain higher levels of calcium. Excessive calcium intake can lead to hypercalcemia, a condition known to cause constipation.
Additives and Fillers: Certain supplements contain additives, fillers, or sweeteners that can upset sensitive stomachs and contribute to digestive problems like bloating or constipation.

The Forms and Sources that Don’t Cause Constipation

The best way to avoid digestive issues is to choose a high-quality, easily digestible form of collagen and use it correctly. Hydrolyzed collagen peptides are your best bet.

Hydrolyzed Collagen (Collagen Peptides)

This is the most recommended form of collagen for gut health because it has undergone a process called hydrolysis. The large collagen protein molecules are broken down into smaller, more easily absorbed peptides. This "pre-digested" state means your body can absorb and utilize it more efficiently, reducing the load on your digestive system and minimizing the risk of bloating and constipation.

Choosing the Right Source

While all hydrolyzed collagen is generally well-tolerated, the source can make a difference, especially for those sensitive to calcium.

Bovine Collagen: Sourced from cows, bovine collagen is rich in Type I and III collagen. It is typically low in calcium, making it an excellent choice for those concerned about calcium-related constipation.
Poultry Collagen: Derived from chickens, poultry collagen is rich in Type II collagen and is also a low-calcium option that is easy on the digestive system.
Marine Collagen: Sourced from fish, marine collagen primarily contains Type I collagen. While highly bioavailable, certain forms derived from shellfish or shark cartilage can be higher in calcium. For sensitive individuals, bovine or poultry might be a safer starting point.

Comparison of Collagen Types for Digestive Health


Feature	Hydrolyzed Bovine/Poultry Collagen	Marine Collagen (Some Sources)	Gelatin (Non-Hydrolyzed)	Plant-Based Boosters
Digestibility	Highly digestible due to small peptides	Highly bioavailable, but depends on processing	Partially broken down, may be harder to digest for some	Not actual collagen; aids body's own production
Risk of Constipation	Low, when paired with adequate hydration and fiber	May be slightly higher if high in calcium	Moderate, especially with dehydration; forms a gel	None directly from collagen, but overall diet matters
Calcium Content	Generally low	Can be high, depending on the source	Varies based on preparation	None
Best For	Overall gut support and general use	Those not sensitive to calcium; skin/bone health	Cooking/recipes, but less suitable for easy digestion	Vegans/vegetarians

Practical Tips to Avoid Constipation While Taking Collagen

To ensure your supplement routine supports, rather than hinders, your digestive health, follow these guidelines:

Stay Hydrated: This is arguably the most important step. Drink plenty of water throughout the day, especially when taking your collagen supplement, to keep stools soft and prevent the hydrophilic collagen from causing dehydration.
Increase Fiber Intake: Balance your increased protein intake by consuming plenty of fiber-rich foods like fruits, vegetables, legumes, and whole grains. This will provide the necessary bulk for regular bowel movements.
Start with a Low Dose: If you are new to collagen, begin with a lower dosage and gradually increase it. This allows your digestive system to adapt to the new protein source over time, minimizing the risk of side effects.
Take it with Food: Some people with sensitive stomachs find it easier to take collagen with a meal rather than on an empty stomach. This can help buffer any changes in stomach acidity.
Choose High-Quality Products: Opt for supplements with minimal additives and transparent ingredient lists. Look for high-quality hydrolyzed collagen peptides from reputable brands.
Incorporate Probiotics: Probiotics are beneficial bacteria that support overall gut health and digestion. Taking them alongside collagen can promote a balanced gut microbiome and further help prevent constipation.

Conclusion

When chosen and used correctly, most types of collagen, particularly hydrolyzed peptides, do not cause constipation. The culprit is typically an imbalance in diet, inadequate hydration, or a high-calcium source. By focusing on hydrolyzed bovine or poultry collagen, ensuring you drink enough water, and balancing your diet with fiber, you can enjoy the many benefits of collagen without the unwelcome digestive side effects. Remember that individual responses vary, so it's essential to listen to your body and adjust your routine as needed.

For more information on collagen supplements, consider reading reliable scientific articles, such as those found on the BBC's health pages, to stay informed about their benefits and proper usage. For example, this article explores collagen supplements in detail.

Frequently Asked Questions

Marine collagen derived from sources like shellfish or shark cartilage can be high in calcium, which may cause constipation in some individuals. Other forms of marine collagen are generally well-tolerated, but it's important to check the calcium content.

Some people can take collagen on an empty stomach without issues, while others, particularly those with sensitive digestion, may find it better to take it with a meal. Taking it with food can help buffer any changes in stomach acidity and reduce discomfort.

Digestive discomfort like bloating and gas can occur when introducing a new protein supplement. This may be due to an imbalance in gut bacteria or your body adjusting to the new intake. Starting with a smaller dose and considering a probiotic can help mitigate these symptoms.

For sensitive digestion, look for a hydrolyzed collagen peptide supplement, which is easier to absorb. Consider bovine or poultry sources, which are typically lower in calcium, and choose a product with minimal additives or fillers.

Stopping collagen is not always necessary. Instead, try increasing your water and fiber intake, reducing your dosage, or taking the supplement with food. If symptoms persist or worsen, consult a healthcare provider.

Yes, for many people, collagen can help with constipation. It contains amino acids like glycine and glutamine that support the gut lining, and it helps attract water into the intestines to keep stools soft.

Collagen powders and capsules both deliver the supplement, but powders are often in a more easily absorbed hydrolyzed form. Capsules are convenient but may be less digestible, depending on the formulation. Liquids are also an option and can be easier on the stomach.