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    As an essential nutrient, collagen is undeniably a health-promoting substance. 

    But if you want to increase your collagen intake while intermittent fasting, you may be wondering, “Does collagen break a fast?” And if so, does collagen break your fast?

    Stirring up the collagen debate: Will it break your fast? Let’s dive into the calorie conundrum and find out if collagen is a “no” or a “go” for your fasting routine.

    Here’s what you need to know about collagen and intermittent fasting. 

    Will collagen break a fast? 

    Does taking collagen break intermittent fasting?

    Whatever questions you have about the relationship between intermittent fasting and collagen — Does collagen protein break a fast? Does collagen powder break a fast? Can you drink collagen while fasting? — the general answer is the same: it depends. 

    While collagen will likely break a fast since it contains calories, not all serving sizes and fasting experiences are equal. 

    So, how do you know if collagen during fasting is a “no” or a “go”?

    Whether you can have collagen while fasting — and your answer to “Will collagen break my fast?” — comes down to you and your fasting goals. For example, if you’re fasting for health reasons, the calories in collagen may disrupt your likelihood of achieving ketosis. 

    Ultimately, everyone’s fasting needs and responses are different. That’s why we always recommend consulting your doctor. 

    We can also help identify what breaks a fast and optimize your fasting experience. Take our SIMPLE quiz so we can get to know you, your body, and your goals, and we’ll whip up some tailored recommendations. 

    What is collagen? 

    Collagen is the most abundant protein in your body — talk about an essential nutrient! 

    There are 28 different types of collagen, and four of them are the building blocks for joints, skin, bones, muscles, organs, and connective tissue.[1,2] 

    Collagen can be found naturally in the flesh of meat and fish, including in bone broth. More recently, it has become widely available in supplement form via capsules, powders, gummies, and liquids.  

    Nutritional value 

    The specific nutritional value of collagen depends on what kind and how much you have.

    Unflavored collagen peptides are pure sources of protein (usually around 18 g / 80 calories per suggested serving). Other collagen supplements (especially gummies and drinks) may contain added flavors, sugars, or other nutrients that affect nutritional value.  

    As a baseline figure, one gram of protein contains four calories. 

    Health benefits and possible drawbacks of using collagen while intermittent fasting

    Whether or not you can take collagen while fasting, what’s in it for you if you do?

    In addition to having possible benefits for skin health,[3] collagen may support common intermittent fasting goals like:

    • improving inflammation, joint health, and muscle recovery [4–6]
    • supporting healthy aging [7]
    • reducing body fat [8]
    • improving heart health [9]

    It may also be beneficial for increasing satiety, as it is a protein at the end of the day (which would be helpful for weight loss, appetite control, and intermittent fasting blood sugar management), though some studies suggest it may not be as effective as other protein supplementation.[10] 

    Likewise, there’s some preliminary evidence that collagen peptides may improve blood sugar levels,[11] but: 

    1. more research into collagen benefits — especially with respect to collagen during fasting — is needed; and 
    2. if intermittent fasting and insulin resistance are a concern, definitely chat with your healthcare provider before modifying any eating habits. 

    Tips on using collagen during a fast 

    1. Consult your doctor. When it comes to mixing intermittent fasting and supplements, it’s not clear-cut which supplements in which contexts may affect your fast. Plus, collagen supplements may not be safe or right for everyone. So, have a chat with your healthcare provider about “Is collagen right for me?” before you get into the particulars of “Does taking collagen break a fast?” and “How can you use collagen while fasting?”  
    2. Check those portions. Mixing a little collagen into black coffee may not equal enough calories to break your fast, but watch out for serving sizes. For fasting-safe drink ideas, check out our guide on what you can drink while fasting.
    3. Take collagen during an eating window. There’s no need to stress about calorie content or when to take collagen when intermittent fasting by keeping collagen out of your fasting period.

    Fill up on nutrient-dense foods. You may not need collagen supplements if you’re getting everything you need from what you eat. Check out our guide on what to eat during intermittent fasting for ideas.

    1. Ricard-Blum S. The collagen family. Cold Spring Harb Perspect Biol. 2011 Jan 1;3(1):a004978.
    2. Nezwek TA, Varacallo M. Physiology, Connective Tissue. StatPearls Publishing; 2022.
    3. Bolke L, Schlippe G, Gerß J, Voss W. A Collagen Supplement Improves Skin Hydration, Elasticity, Roughness, and Density: Results of a Randomized, Placebo-Controlled, Blind Study. Nutrients [Internet]. 2019 Oct 17;11(10).
    4. Honvo G, Lengelé L, Charles A, Reginster JY, Bruyère O. Role of Collagen Derivatives in Osteoarthritis and Cartilage Repair: A Systematic Scoping Review With Evidence Mapping. Rheumatol Ther. 2020 Dec;7(4):703–40.
    5. García-Coronado JM, Martínez-Olvera L, Elizondo-Omaña RE, Acosta-Olivo CA, Vilchez-Cavazos F, Simental-Mendía LE, et al. Effect of collagen supplementation on osteoarthritis symptoms: a meta-analysis of randomized placebo-controlled trials. Int Orthop. 2019 Mar;43(3):531–8.
    6. Khatri M, Naughton RJ, Clifford T, Harper LD, Corr L. The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review. Amino Acids. 2021 Oct;53(10):1493–506.
    7. Wang H. A Review of the Effects of Collagen Treatment in Clinical Studies. Polymers [Internet]. 2021 Nov 9;13(22).
    8. Tak YJ, Kim YJ, Lee JG, Yi YH, Cho YH, Kang GH, et al. Effect of Oral Ingestion of Low-Molecular Collagen Peptides Derived from Skate (Raja Kenojei) Skin on Body Fat in Overweight Adults: A Randomized, Double-Blind, Placebo-Controlled Trial. Mar Drugs [Internet]. 2019 Mar 7;17(3).
    9. Tomosugi N, Yamamoto S, Takeuchi M, Yonekura H, Ishigaki Y, Numata N, et al. Effect of Collagen Tripeptide on Atherosclerosis in Healthy Humans. J Atheroscler Thromb. 2017 May 1;24(5):530–8.
    10. Duarte GMF, de Freitas KV, Marini ACB, Giglio BM, Fernandes RC, Lobo PCB, et al. Acute supplementation with whey protein or collagen does not alter appetite in healthy women: a randomised double-blind and crossover pilot study. Br J Nutr. 2022 Jul 28;128(2):345–51.
    11. Zhu C, Zhang W, Mu B, Zhang F, Lai N, Zhou J, et al. Effects of marine collagen peptides on glucose metabolism and insulin resistance in type 2 diabetic rats. J Food Sci Technol. 2017 Jul;54(8):2260–9.