Can you take collagen during intermittent fasting

Can You Take Collagen During Intermittent Fasting?

Andrew Brewer - Intermittent Fasting Expert

Written by Andrew Brewer. Updated on March 2023.

Medically reviewed and fact checked by our team.

Can you take collagen during intermittent fasting

Collagen supplements are very popular because they help improve your hair, skin, and nail health, promoting elasticity, strength, and thickness that will improve how you look and feel. 

The effects of collagen supplements are actually found more than skin deep too. Collagen can help you improve the well-being of your tissues, keep your joints in good shape, and promote internal organ health. 

Collagen is found throughout your body, and many people like to add a scoop of collagen powder with their black coffee to get the best results. As an added bonus, collagen is a protein, meaning it helps curb hunger. You’re tricking your body into thinking it’s eaten, so you won’t feel hungry. If it helps you skip meals, you should be able to take it while intermittent fasting without breaking your fast, right? Unfortunately, the answer is a little bit more complicated, and the jury’s still out if it’s okay to take while fasting. Strict schools of thought say no, while others say it’s fine. Here are both positions so you can make the right choice for yourself. 


Some intermittent fasters focus only on calories. If something has calories, no matter how few, then you’ve broken your fast. A scoop of collagen has about 35 calories – and if you mix it with black coffee – your “breakfast” will set you back about 40 calories. So yes, if you subscribe to this school of thought, then taking collagen will break your fast. 

This is because it will impact autophagy, which is when the body gets rid of damaged or dying cells and replaces them with healthy new ones. This is one of the biggest benefits of intermittent fasting. You’ll force your body into autophagy, so while it may not feel like it at first, you’ll actually come out of your fast feeling healthier, in addition to losing weight. 

Any amount of calories may delay your body’s ability to enter autophagy, which is why some intermittent fasters only stick to water during their fasting windows. 


Instead of calories, some people focus on how your body processes energy. When your body doesn’t have enough carbs and sugars to burn for energy, it will start producing something called ketones by burning fat. This is one way that you lose weight during intermittent fasting. When your body is in ketosis, you’re burning your fat stores. 

You can technically eat a few calories without breaking ketosis, and that includes some collagen supplements. You’ll want to check the nutritional label to ensure that your collagen doesn’t include other ingredients that would break ketosis. If it only includes collagen peptides and no carbs, it will not impact ketosis. If it does, find a new supplement if you plan on taking it during intermittent fasting or only take it during your eating windows. 

So, Can I Take Collagen During Fasting?

The answer to if you can take collagen during fasting is up to you. If you’re worried about calories and potentially breaking autophagy, then you’ll want to hold off on the collagen supplements until your eating windows. If you’re more focused on keeping your body in ketosis and preventing any insulin triggers, then you can take collagen supplements while intermittent fasting as long as the supplements do not contain protein. Read the label carefully to prevent any unwanted metabolic responses in your body. 

Collagen can help you look more youthful from the inside out, so it’s no wonder you want to take it during intermittent fasting. It’s your choice, but it will technically break a fast because it has calories, but since it doesn’t spike your insulin or break ketosis, do those 35 calories matter? No one can answer that question but you.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!