Intermittent fasting can make an otherwise simple supplement routine surprisingly confusing.
You stop eating at 8pm.
You don't plan to eat again until midday.
Then morning arrives.
Can you take your creatine?
What about electrolytes?
Does a multivitamin count as food?
Can you use pre-workout before fasted training?
And if you drink a protein shake, have you definitely broken the fast?
The problem is that "breaking a fast" doesn't always mean exactly the same thing.
Someone using intermittent fasting simply to control when they eat may have different priorities from someone fasting for religious reasons or following a specific medical protocol.
For everyday intermittent fasting, however, there's a useful practical distinction:
Does the supplement provide meaningful energy or nutrients that effectively turn your fasting period into an eating period?
A protein shake clearly isn't equivalent to swallowing a creatine capsule.
Plain electrolytes aren't nutritionally equivalent to an electrolyte drink containing sugar.
And just because you can take a particular vitamin without food doesn't necessarily mean that's the best time to take it.
So rather than creating an enormous list of fasting-approved and fasting-banned supplements, let's look at what you're actually consuming.
1. Can You Take Supplements While Intermittent Fasting?
Yes, but whether you should take them during the fasting window depends on the supplement.
Intermittent fasting describes an eating pattern built around alternating periods of eating and fasting.
One common approach is 16:8 fasting, where someone fasts for approximately 16 hours and consumes their food within an eight-hour eating window.
If your eating window runs from midday until 8pm, for example, you might naturally wonder what happens to supplements you normally take at breakfast.
The answer doesn't have to be:
Stop taking all of them.
Some supplements can potentially fit into the fasting period.
Others are clearly better suited to the eating window.
And for plenty of supplements, moving the timing by a few hours isn't going to undermine their usefulness.
Creatine is a good example.
If you normally take Animal Creatine Capsules at 8am but begin intermittent fasting, you don't need to abandon creatine because breakfast has disappeared.
Depending on the product formulation and your fasting approach, you could potentially take it during the fast.
Or you could simply move it to lunch.
Consistency over time matters considerably more than desperately trying to preserve the exact time you used to take it.
2. Do Supplements Break an Intermittent Fast?
Some do.
Some don't meaningfully do so in the conventional sense.
And some sit in a grey area depending on their formulation and how strictly you've defined your fast.
A straightforward way to think about it is to ask what the supplement actually provides.
Protein, Carbohydrates and Fat
If a supplement provides a meaningful amount of these nutrients, you're consuming energy.
A protein shake is therefore very different from a calorie-free tablet.
If your goal is maintaining a conventional fasting window with no meaningful caloric intake, something providing protein, carbohydrates or fat belongs in your eating window.
Vitamins and Minerals
Vitamins and minerals themselves aren't equivalent to eating a meal.
But the complete supplement still matters.
A gummy vitamin, for example, may contain sugar and calories.
A capsule may contain other ingredients.
And certain vitamins are better absorbed with food anyway.
Amino Acids
Amino acids aren't simply flavoured water.
They're the building blocks of protein and can produce metabolic responses associated with nutrient intake.
If you're trying to maintain a conventional fast, amino-acid products aren't the obvious choice for your fasting window.
Creatine
Creatine is different again.
Plain creatine doesn't function like consuming protein, carbohydrate or fat.
This is why asking:
"Do supplements break a fast?"
without specifying the supplement doesn't get us very far.
Read the nutritional information.
The answer is often sitting on the label.
3. Which Supplements Can You Take Without Breaking a Fast?
Supplements that provide no meaningful calories are generally the most compatible with a conventional intermittent fasting window.
Depending on the specific formulation, that might include things such as:
- plain creatine
- certain vitamins and minerals
- calorie-free electrolytes
- some caffeine products
But don't turn that into a universal list.
The formulation wins.
Take electrolytes.
Sodium, potassium and magnesium aren't carbohydrates.
But an electrolyte drink product might contain sugar or other calorie-containing ingredients.
Likewise, caffeine itself isn't the same thing as drinking a sugary energy drink.
A supplement's category therefore isn't enough to determine whether it fits your fast.
There's another consideration:
How does it make you feel without food?
A supplement could theoretically fit within your definition of fasting while making you nauseous every time you take it on an empty stomach.
At that point, what are you achieving by forcing it into the fasting window?
Move it.
Your eating window exists every day.
Use it.
4. Can You Take Vitamins and Minerals While Fasting?
Potentially, but the better question is often whether there's any advantage to doing so.
Some vitamins are water-soluble, including vitamin C and the B vitamins.
Others are fat-soluble:
- vitamin A
- vitamin D
- vitamin E
- vitamin K
Fat-soluble vitamins are absorbed alongside dietary fat.
That makes your eating window a logical place for supplements containing them.
Suppose you're using Applied Nutrition Vitality Vitamin D3.
Rather than worrying about whether taking the supplement at 9am technically disrupts your fast, you could take it with an appropriate meal during your eating window.
You've simplified the fasting question and given the fat-soluble vitamin dietary fat to accompany its absorption.
Multivitamins can also contain several nutrients with different absorption considerations.
And some people find vitamin and mineral supplements uncomfortable when taken without food.
Again:
Being able to take something while fasting doesn't automatically make fasting the best time to take it.
If the directions recommend taking a supplement with food, intermittent fasting isn't a reason to ignore them.
Move it into your eating window.
5. Does Creatine Break a Fast?
Plain creatine is unlikely to meaningfully break a conventional intermittent fast in the way consuming protein, carbohydrate or fat would.
Creatine doesn't provide a meaningful source of dietary energy in the same sense as those macronutrients.
That means someone using Animal Creatine Capsules doesn't necessarily need to stop taking creatine during their fasting window purely because they're fasting.
But there are two qualifications.
First:
Check the complete product.
Creatine may be the active ingredient, but products come in different formats and formulations.
A plain creatine product isn't necessarily nutritionally identical to a flavoured creatine drink containing other ingredients.
Second:
Creatine timing isn't something you need to obsess over.
The benefits of creatine supplementation are associated with increasing and maintaining muscle creatine stores through consistent supplementation.
You're not relying on an immediate effect that disappears if you take today's serving at 1pm instead of 8am.
So if you'd rather keep your fasting window completely free from supplements, take your creatine during your eating window.
If your particular creatine product fits your fasting approach and you prefer taking it earlier, that's another option.
What doesn't make much sense is compromising consistency because you're worried that moving creatine by a few hours will ruin its effects.
Intermission
Intermittent fasting doesn't require you to abandon your supplement routine.
It requires you to look at what each supplement actually contains.
Products providing meaningful protein, carbohydrates or fats are fundamentally different from essentially non-caloric supplements.
Some vitamins and minerals may technically fit within a fasting window, yet still make more sense with food.
And plain creatine doesn't need to become complicated simply because you've stopped eating breakfast.
The bigger lesson is that supplement timing should work around your fasting routine rather than dominate it.
In Part 2, we'll look at electrolytes during fasting, caffeine and pre-workout, why protein shakes and amino acids are different, whether supplements are better during the fast or eating window, and which products are particularly sensible to take alongside food.
Part 2
6. Do Electrolytes Break a Fast?
Not necessarily.
Electrolytes themselves—such as sodium, potassium and magnesium—aren't equivalent to consuming protein, carbohydrate or fat.
So a genuinely calorie-free electrolyte product may fit comfortably within a conventional intermittent fasting window.
The important phrase there is:
Calorie-free.
An electrolyte product can contain much more than electrolytes.
Some formulations include sugar or other carbohydrates. Others may contain sweeteners, flavourings and additional ingredients.
That's why something like Optimum Nutrition Electrolyte should be judged by its actual nutritional information and directions rather than assuming:
"It's electrolytes, so it can't break my fast."
Check the label.
If a product provides meaningful calories, it doesn't fit a strict calorie-free fasting window in the same way as plain electrolytes.
Electrolytes can become particularly relevant if you're combining intermittent fasting with training.
If you exercise during your fasting window—especially in hot conditions or during sessions involving substantial sweating—you'll still lose water and electrolytes through sweat.
Fasting doesn't switch those losses off.
But that doesn't mean everyone practising intermittent fasting suddenly needs an electrolyte supplement either.
For a relatively short fasting period during an ordinary day, your normal diet and hydration may be perfectly adequate.
Use electrolytes because your circumstances justify them.
Not because fasting automatically requires them.
7. Does Pre-Workout or Caffeine Break a Fast?
Plain caffeine doesn't provide meaningful calories in the way food does.
That's why black coffee is commonly consumed during intermittent fasting.
But caffeine and pre-workout aren't interchangeable terms.
A pre-workout can contain:
- caffeine
- amino acids
- carbohydrates
- sweeteners
- flavourings
- minerals
- numerous performance ingredients
So while caffeine itself may fit into a fasting window, you need to check the complete formulation of a product such as Optimum Nutrition Platinum Pre-Workout before deciding whether it fits your particular fasting approach.
There's also the question of whether you actually tolerate it.
Taking a strong pre-workout on an empty stomach can feel noticeably different from taking it after eating.
Some people may experience nausea, stomach discomfort, shakiness or a more pronounced caffeine effect.
If fasted pre-workout makes you feel awful, there's no prize for enduring it.
You could train during your eating window instead.
Or adjust when you use the supplement.
And remember that intermittent fasting doesn't make the usual considerations around caffeine disappear.
Your total daily caffeine intake still matters, particularly if you're combining pre-workout with coffee, tea, energy drinks or other caffeinated products.
8. Do Protein Shakes and Amino Acids Break a Fast?
For a conventional intermittent fast, yes—protein shakes should be considered as breaking the fast.
Protein provides energy.
It also supplies amino acids and produces physiological responses associated with nutrient intake.
A serving of Per4m Whey Hydrate therefore belongs in your eating window if your aim is to maintain a calorie-free fasting period.
This shouldn't be controversial.
A protein shake is nutrition.
The fact that you drink it rather than chew it doesn't somehow turn it into fasting.
Amino-acid supplements create a similar problem.
BCAAs—branched-chain amino acids—are still amino acids.
Essential amino acid products are still amino acids.
If you're trying to maintain a conventional fast, consuming amino acids specifically to provide nutrients to your body works against the basic idea of not consuming nutrients during that period.
This becomes particularly relevant around fasted training.
Someone might think:
"I'll train fasted, but I'll have protein beforehand so I don't lose muscle."
Once you've consumed the protein, you're not really training in the same nutritional state that people generally mean when they say fasted training.
That doesn't make the workout worse.
It simply means you've eaten.
And if consuming protein before training helps you perform or makes your routine easier to sustain, there's nothing inherently wrong with moving the workout into your eating period.
Your muscles don't award extra points because you trained hungry.
9. Should You Take Supplements During Your Fast or Eating Window?
For many supplements, the eating window is simply easier.
You don't need to ask whether they contain a tiny amount of energy.
You don't need to worry about whether taking them without food will upset your stomach.
And supplements that benefit from being consumed alongside food already have a meal available.
That doesn't mean everything must be taken with food.
Instead, divide your routine practically.
During the Fasting Window
Essentially non-caloric supplements may potentially fit here if:
- the formulation is appropriate
- the directions allow it
- you tolerate them without food
- they fit your definition and purpose of fasting
During the Eating Window
This is the obvious place for:
- protein shakes
- amino-acid products
- supplements containing meaningful calories
- supplements specifically directed to be taken with food
- products that make you uncomfortable on an empty stomach
Then there are supplements such as creatine where you may have flexibility.
If Animal Creatine Capsules fit conveniently alongside lunch, take them then.
There's little reason to turn your fasting schedule into a complicated timetable purely to take creatine at a particular hour.
The best supplement routine is usually one you're able to follow consistently.
10. Which Supplements Are Best Taken With Food When Intermittent Fasting?
Intermittent fasting makes this question particularly useful because you already have a clearly defined eating window.
Use it.
Fat-Soluble Vitamins
Vitamins A, D, E and K are fat-soluble.
Taking them alongside a meal containing some dietary fat can support their absorption.
That's why Applied Nutrition Vitality Vitamin D3 fits naturally into the eating window.
You don't gain anything useful by deliberately taking it halfway through your fast just because you technically can.
Multivitamins
Many multivitamins contain a mixture of water-soluble and fat-soluble vitamins alongside minerals.
Taking them with an appropriate meal can therefore make sense and may also improve tolerance for people who experience nausea when taking multivitamins on an empty stomach.
Protein Supplements
Protein obviously belongs in the eating window if you're maintaining a conventional fast.
Supplements That Upset Your Stomach
This category depends on you.
If a product repeatedly makes you nauseous when taken without food and its directions permit taking it with a meal, move it into your eating window.
There's no reason to make your supplement routine unnecessarily uncomfortable.
The bigger principle is:
Don't sacrifice sensible supplement use just to squeeze everything into your fasting window.
Your eating window exists for a reason.
Conclusion
So, can you take supplements while intermittent fasting?
Yes.
But not every supplement makes sense during the fasting period.
The easiest distinction is between products that provide meaningful nutrition and those that essentially don't.
Protein shakes provide protein and calories, so they belong in your eating window if you're maintaining a conventional calorie-free fast.
Amino acids—including BCAAs—also aren't simply flavoured fasting water.
Plain creatine is different. Animal Creatine Capsules can potentially fit around intermittent fasting without needing an elaborate timing strategy, although checking the complete formulation still matters.
Electrolytes require the same label-reading approach. The minerals themselves aren't equivalent to consuming food, but an electrolyte product may contain calorie-providing ingredients.
Caffeine itself doesn't meaningfully provide calories, while a complete pre-workout formula needs to be assessed according to what's actually inside it.
And some supplements are simply better suited to your eating window.
Fat-soluble vitamins such as Applied Nutrition Vitality Vitamin D3 are an obvious example.
Intermittent fasting shouldn't make supplementation complicated.
Check the formulation.
Follow the directions.
Put calorie-containing products in your eating window.
Take supplements with food when doing so improves absorption or tolerance.
And don't obsess over supplement timing when moving something a few hours would solve the entire problem.
FAQ
1. Can you take supplements while intermittent fasting?
Yes. Some supplements can fit within a fasting window, while calorie-containing products and supplements better taken with food are generally more appropriate during the eating window.
2. Do supplements break intermittent fasting?
Some do. Products providing meaningful protein, carbohydrates, fats or calories generally break a conventional calorie-free fast. Other essentially non-caloric supplements may not.
3. What supplements don't break a fast?
Depending on their formulation, plain creatine, calorie-free electrolytes, certain vitamins and minerals and caffeine may potentially fit into a fasting window. Always check the complete product.
4. Do vitamins break a fast?
Vitamins themselves don't generally provide meaningful calories, but the complete supplement formulation matters. Some vitamins are also better taken with food.
5. Does creatine break a fast?
Plain creatine doesn't provide meaningful food energy in the way protein, carbohydrate or fat does, so it can generally fit within a conventional intermittent fasting approach. Check additional ingredients in the particular product.
6. Do electrolytes break a fast?
Electrolyte minerals themselves don't necessarily break a conventional fast. However, electrolyte products containing meaningful sugar or other calorie-providing ingredients are different.
7. Does pre-workout break a fast?
It depends on the formulation. Caffeine itself doesn't meaningfully contribute calories, but complete pre-workout products can contain numerous other ingredients, so check the label.
8. Does protein powder break a fast?
Yes, for conventional intermittent fasting. Protein powder provides protein, amino acids and energy and should generally be consumed during the eating window.
9. Do BCAAs break a fast?
If your goal is a conventional nutrient-free fasting window, BCAAs don't really fit it. They are amino acids rather than a calorie-free mineral or stimulant.
10. When should you take supplements while intermittent fasting?
Use the fasting window for appropriate essentially non-caloric supplements if desired. Use your eating window for protein, amino acids, calorie-containing products, fat-soluble vitamins and supplements that are better tolerated with food.
