Side Effects of Collagen Supplements

Date: July 1, 2025 | Scientifically Reviewed by Omer Matt Sermet

Collagen supplements are popular products believed to provide benefits in many areas, from skin health to joint function. However, like any supplement, collagen use can have some side effects. This article thoroughly discusses the common and rare side effects of collagen supplements, ways to minimize potential risks, and general safety information. You will find comprehensive answers to all your questions, from digestive issues and allergic reactions to potential effects on the kidneys and concerns about product quality.

Side Effects of Collagen Supplements

Side Effects of Collagen Supplements-CollaVita

What are the Common Side Effects of Collagen Supplements?

While collagen supplements are generally well-received by most individuals, it's wise to be aware of the more commonly reported, though typically mild, side effects:

  • Digestive Discomfort
  • Allergic Reactions
  • Unpleasant Taste or Smell

Digestive Discomfort

For the majority of users, collagen supplements are easily digested. However, scientific studies suggest that approximately 3-5% of individuals might experience mild digestive issues, particularly when first starting supplementation or when consuming higher doses. These symptoms are usually temporary and can include:
  • Bloating:  A feeling of fullness or swelling in the abdomen.
  • Mild gastrointestinal discomfort:  A sensation of being overly satisfied even after consuming a normal amount of food.
  • Occasional Heartburn: A burning sensation in the chest, often after eating.
On the other hand, the effects of collagen supplements on the digestive system are generally positive. For instance, a 2022 study published in JMIR Formative Research titled "Effect of a Daily Collagen Peptide Supplement on Digestive Symptoms in Healthy Women: 2-Phase Mixed Methods Study"(1) investigated the effects of a daily 20-gram collagen peptide supplement on digestive symptoms in healthy adult women. According to the findings of this study, 93% (13/14) of the 14 participants who completed Phase 2 experienced a reduction in digestive symptoms, including bloating. These results suggest that collagen supplementation has the potential to alleviate existing digestive discomfort.

Allergic Reactions

Allergic reactions to collagen supplements are relatively uncommon but can occur, particularly in individuals with pre-existing allergies to specific protein sources. The risk can vary depending on the collagen source:
  • Marine collagen (from fish):  Presents a higher risk for those with known allergies to fish or shellfish
  • Bovine collagen (from cattle): Carries a potential risk for individuals with beef allergies.
  • Porcine collagen (from pigs): May cause reactions in those sensitive to pork products.
A 2021 study published in the journal Polymers, A Review of the Effects of Collagen Treatment in Clinical Studies(2), also suggests that collagen supplements are generally well tolerated, but there is a risk of allergic reactions in individuals with existing allergies to the source material (e.g., seafood, beef).

Unpleasant Taste or Smell

Some collagen supplements, particularly those derived from marine sources, might have a slightly unpleasant taste or odor. This sensory issue is typically mild and temporary, as highlighted in a 2022 study in International Journal of Food Science and Technology: "Fish and fish products naturally possess characteristic odors, which can impact their appeal and usability. Deodorization processes utilizing physical, chemical, and biological methods have proven effective in addressing these sensory challenges in collagen peptide products"(3).
Fortunately, manufacturers have responded effectively to this concern by developing a variety of flavored options and by implementing advanced processing techniques to minimize any unpleasant sensory experiences. Modern collagen supplements often feature natural flavors or are formulated to be virtually tasteless and odorless, which significantly enhances the user experience and makes it easier to adhere to a collagen routine.

What Are the Rare Side Effects and Concerns of Collagen Supplements?

Here are the rare side effects of collagen supplements:
  • Potential Kidney Strain
  • Hypercalcemia Concerns
  • Cardiovascular Effects
  • Standardization and Quality Concerns

Potential Kidney Strain

High-quality collagen supplements generally pose a minimal risk to kidney health in individuals with normal renal function. However, some lower-quality products might contain trace amounts of heavy metals or other contaminants that could potentially impact kidney function with prolonged use.

The study by Gupta et al. (2024), published in Cureus and titled "A Comprehensive Review of Biomarkers for Chronic Kidney Disease in Older Individuals: Current Perspectives and Future Directions"(4) emphasizes the importance of biomarkers for the early diagnosis and management of chronic kidney disease. This review examines how traditional and novel biomarkers contribute to a more accurate understanding of kidney health.

The review specifically highlighted that low-quality collagen may contain trace quantities of oxalate, which could potentially increase the risk of kidney stone formation in susceptible individuals. Therefore, individuals with a history of kidney stones or impaired renal function should always consult with their healthcare provider before starting collagen supplementation.

Hypercalcemia Concerns

Some researchers have theorized that marine collagen supplements, especially those derived from fish bones, might contain elevated calcium levels that could potentially lead to hypercalcemia (high levels of calcium in the blood) in susceptible individuals. However, the general scientific consensus is that collagen supplements do not directly increase serum calcium levels. Collagen and calcium have different functions; while calcium is an essential mineral for bone strength, collagen is a protein that provides structure to bones, skin, and connective tissues. Nevertheless, since marine-sourced collagen products can naturally contain calcium, individuals with pre-existing kidney conditions or a risk of hypercalcemia should consult healthcare providers before using such supplements.

Cardiovascular Effects

The researchers observed that "the decrease in systolic blood pressure associated with collagen peptide supplementation may significantly reduce the risk of heart disease and stroke in at-risk populations." This finding suggests that collagen supplements may offer cardiovascular benefits without posing risks when used appropriately.

Standardization and Quality Concerns

A significant area of consideration with collagen supplements revolves around standardization and quality control within the industry. Currently, there's a lack of universally standardized methods for the extraction and purification of collagen, particularly marine collagen. This inconsistency can contribute to variations in the purity, efficacy, and potential for allergic reactions among different collagen supplements.

This means that the quality and effectiveness of collagen supplements can differ considerably depending on the manufacturer and their processes. As a consumer, it's essential to prioritize products from reputable companies that are transparent about their sourcing and ideally conduct independent, third-party testing to ensure the quality and purity of their collagen. Look for certifications or seals of approval from recognized organizations that verify the contents and safety of dietary supplements. Choosing high-quality, well-vetted products is a crucial step in maximizing the benefits of collagen while minimizing potential risks.


How to Minimize the Risk of Side Effects?

The good news is that many healthcare professionals, nutritionists, and scientists agree that the side effects of collagen peptides are generally minimal for healthy individuals. However, if you are currently taking medication, have a sensitive digestive system, or have any reason to believe your body might react differently to supplements, consider these strategies to minimize potential side effects:

  • Start Slow and Increase Dosage Gradually: Allow your body to adapt to collagen supplementation by starting with a lower dose than recommended and gradually increasing it until you reach your optimal intake. This approach gives your digestive system time to adjust and reduces the likelihood of gastrointestinal discomfort.
  • Choose High-Quality Products: Selecting high-quality collagen supplements is paramount for minimizing potential side effects and maximizing the benefits. Low-quality products may contain harmful contaminants such as heavy metals, pathogens, pesticides, herbicides, genetically modified organisms, and even traces of animal excrement.
  • Consider Temperature Effects: Research suggests that high temperatures, like those in very hot beverages, can negatively impact the quality of collagen supplements.
  • Drink Plenty of Water: Staying adequately hydrated is crucial when taking collagen supplements. Drinking at least 8 ounces of water around two hours after taking your collagen, or with meals, helps with better absorption and can reduce the chances of digestive discomfort.
  • Consider Your Allergies: When choosing collagen supplements, always be mindful of potential allergic reactions, particularly if you have known allergies to specific protein sources. If you have a seafood allergy, it's best to consider alternatives to marine-derived collagen.
  • Consult Healthcare Professionals: If you're currently taking any medications or managing any pre-existing health conditions, it is essential to consult with your healthcare provider before starting collagen supplementation. This is particularly important for pregnant or breastfeeding women, individuals with chronic health conditions, those taking multiple medications, and people with a history of allergic reactions to supplements.
  • Optimal Timing: If you find that collagen supplementation causes you gastrointestinal issues, try adjusting the timing of when you take it. Taking collagen with your meals or in the morning with breakfast can often help to reduce digestive discomfort.
How to minimize risk of side effects?-CollaVita

Is Collagen Safe for Everyone?

Collagen is widely considered safe for healthy individuals to take as a supplement, with numerous studies confirming its safety profile. A systematic review published in the Nutritional Medicine Journal in 2022, Collagen: A Review of Clinical Use and Efficacy(5), notes that many different forms of oral collagen are considered highly biocompatible and safe as a supplement. The study strongly suggests that collagen supplements have positive therapeutic effects on osteoarthritis pain management, blood sugar control in type II diabetes, wound healing, skin aging, and post-exercise body composition and strength.

A comprehensive safety assessment conducted by the Cosmetic Ingredient Review (CIR) Expert Panel, an independent organization that evaluates the safety of cosmetic ingredients, provides important information regarding the safety of collagen and related proteins. This assessment, titled "Safety Assessment of Skin and Connective Tissue-Derived Proteins and Peptides as Used in Cosmetics"(6) states that while 19 collagen and connective tissue-derived proteins and peptides were evaluated as safe.

Ingredients Evaluated as Safe:

    • Ammonium Hydrolyzed Collagen
    • Atelocollagen
    • Calcium Hydrolyzed Collagen
    • Collagen
    • Elastin
    • Fibronectin
    • Gelatin
    • Hydrolyzed Actin
    • Hydrolyzed Elastin
    • Hydrolyzed Fibronectin
    • Hydrolyzed Collagen
    • Hydrolyzed Gelatin
    • Hydrolyzed Reticulin
    • Hydrolyzed Spongin
    • MEA-Hydrolyzed Collagen
    • Soluble Collagen
    • Hydrolyzed Spongin
    • Soluble Elastin
    • Zinc Hydrolyzed Collagen

    This safety profile makes collagen supplements suitable for most adults, although individual responses may vary depending on personal health factors and the specific collagen product used.

    Frequently Asked Questions About Collagen Side Effects

    Can collagen supplements cause allergic reactions?

    Yes, especially if you have existing allergies to the source of the collagen (fish, beef, or pork). Always check the source before using. For more information on different collagen types and sources, read our guide on What Are the Types of Collagen?

    Are there any digestive side effects from taking collagen?

    Around 3-5% of users may experience mild digestive issues, such as bloating or heartburn, particularly when starting. Taking collagen with meals can help minimize this. You may also want to explore natural, collagen-rich foods, as discussed in 'What Foods are Rich in Collagen?'

    Are there vegan alternatives to collagen supplements that don't cause side effects?

    Yes, plant-based collagen boosters can provide the nutrients your body needs to produce its own collagen, such as silica from bamboo leaf extract and Vitamin C from amla berry. These are often well-tolerated. Learn more in What Are the Alternatives to Animal-Based Collagen Boosters?.

    Can collagen supplements interact with medications?

    While generally safe, it's always best to consult your healthcare provider if you are pregnant, breastfeeding, have chronic health issues, or are taking multiple medications.

    Is collagen safe during pregnancy and breastfeeding?

    While collagen may offer benefits during this time, consulting your healthcare provider before starting any supplement, including collagen, is crucial. For detailed information, see our guide Can You Take Collagen While Pregnant?.




    SOURCES

    (1) - Abrahams M, O'Grady R, Prawitt J. Effect of a Daily Collagen Peptide Supplement on Digestive Symptoms in Healthy Women: 2-Phase Mixed Methods Study. JMIR Form Res. 2022 May 31;6(5):e36339. doi: 10.2196/36339. PMID: 35639457; PMCID: PMC9198822.

    (2) - Wang, H. A Review of the Effects of Collagen Treatment in Clinical Studies. Polymers 2021, 13, 3868. https://doi.org/10.3390/polym13223868

    (3) - Xilong Wang, Bei Le, Na Zhang, Kathrine H Bak, Yuhao Zhang, Yu Fu, Off-flavour compounds in collagen peptides from fish: Formation, detection and removal, International Journal of Food Science and Technology, Volume 58, Issue 3, March 2023, Pages 1543–1563.

    (4) - Gupta, S., Kumar, R., & Singh, S. (2024). A Comprehensive Review of Biomarkers for Chronic Kidney Disease in Older Individuals: Current Perspectives and Future Directions. Cureus, 16(9), e68798.

    (5) - Steele, C. (2022) Collagen: a review of clinical use and efficacy. Nutr Med J., 1 (2): 12-36.

    (6) - Cosmetic Ingredient Review Expert Panel. (2006). Safety Assessment of Skin and Connective Tissue-Derived Proteins and Peptides as Used in Cosmetics. International Journal of Toxicology, 25(Suppl 2), 1-132.

     

    Scientifically Reviwed by Omer (Matt) Sermet

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