Isopure Zero Carb review: Are the Benefits Worth it, and What are the Side-Effects?

Image of a strong woman drinking a weight gain shake

When we first heard there was a protein powder with zero carbs, we thought it was too good to be true, so we dismissed it and carried on with our day. Our past experiences told us that "zero carbs" usually means loaded with fat, or jam-packed with sweeteners.

Recently though, we decided to change our tune, and created a full Isopure Zero Carb review, to see how this innocent looking 100 calorie shake stands up to scrutiny.

To our surprise, it performed rather well in most of our tests.

And you'll soon learn why.

Isopure Zero Carb Nutrition Facts

As you probably guessed from the brand name, there are absolutely zero carbs in this supplement. In fact, the only macronutrient is protein. At 4 calories per gram, we get 100 calories total from the protein, which is pure whey isolate.

While there may only be one macronutrient, there are a remarkable amount of vitamins and minerals, which aside from having zero calories, is one reason it's so popular with the health-focused crowd.









 Whey Isolate




In total, Isopure packs a staggering 25 vitamins and minerals to complement the 25 g of whey protein isolate. On the minerals side of things, there's 25% of the RDI for calcium, 25% of the RDI for magnesium, and 40% of the RDI for zinc, among many other vital nutrients.

As for the vitamins, one scoop gets us 40% of the RDI for vitamin A, 35% of the RDI for vitamin E, and 15% of the RDI for vitamin K. At a dose of 2 scoops a day, it has a more powerful vitamin and mineral composition than some multivitamins we've tried!

Isopure Zero Carb Ingredient Breakdown

Whey protein isolate is the ingredient that make up 100% of Isopure's calories. Not a single gram of the 100 calorie total comes from carbs, sugar, or fat. For those trying to lose weight, or just top up their protein intake, this is by far the most compelling feature.

The greatest thing about whey isolate is that it's not jockeying for position with carbs or fats, and as a result, is absorbed much more rapidly than any other protein we currently have available to us.

And while isolate is usually costlier than concentrate, you only pay for protein when you choose isolate — no extra carbs, fats, and lactose. The latter is also whey isolate is suitable for those who are lactose intolerant, or those who just don't respond well to its effects.

Isopure isn't 100% lactose-free, but typically, well-made whey isolates have less than 1% total lactose, which is significantly less than whey concentrate.

Who Can Benefit From Taking It?

Anyone who wants to enrich their diet with protein, vitamins, and minerals, can benefit from taking Isopure regularly. With only 100 calories, there's not much to dislike. But if you already take a multivitamin, you may want to try something different.

As one of the lowest calorie protein powders on the market, those who will find it most useful, are those trying to lose weight or get leaner. However, anyone seeking a quality boost in protein can enjoy its effects as well.

Is It Good For Weight Loss?

If losing weight was easy, nobody except the genetically unfortunate would be fat. And if getting lean was easy, bodybuilders wouldn't binge-eat after a contest. So what gives?

Well, being liquid calories, you don't want to spend much of your calorie budget on protein shakes. It's like bargaining for a good deal, we're trying to get as much protein as possible, for the least amount of calories. Why would you consume more calories to get the same amount of protein?

Isopure can also be a game changer for weight loss diets. All the calories are from protein which makes sticking to a low-carb diet easier.

It doesn't make sense. Ideally, for every gram of protein, we should only accumulate 4 calories because as a macronutrient, protein is 4 calories per gram. Getting anymore than that means that pesky carbs and fats have snuck into our shake, which over time eats away at our calorie budget.

Isopure is 100% protein. All of the 100 calories are sourced from exclusively whey isolates. You can even do the maths:

Protein in Isopure ✕ Calories In Protein = total calories
25 g ✕ 4 = 100

How To Properly Use

While drinking Isopure won't make you lose weight, it sure can help alongside a suitable diet and hard training. Here's how to use it properly:

  • Mix one scoop with 6-12 oz of cold water
  • Use less water for a thicker consistency (optional)
  • Shake until all clumps have dissolved
  • Add more water if it is too sweet

You can also add milk to make it thicker and more creamy, but of course, this means adding more calories, which isn't ideal for everyone.

When Should You Take It?

The primary purpose of Isopure Zero Carb is to supplement your diet with extra protein — without the calorie baggage.

So there's no real wrong time to take it.

However, to enjoy its best effects, consuming it around your workout, is a sensible idea for muscle growth and recovery for training.

But should you take it before or after?

a sporty woman having a protein shake after her workout

Pre vs Post Workout

You don't want to train fasted, but you also need protein after your workout, so when should you take Isopure Zero Carb?

Presuming you have a whole foods meal before training, take Isopure after your session if you want to maximize its effects. At this time, you have accumulated more muscle damage and fatigue, which requires excess amino acids to repair microtraumas, grow new muscle, and bring down whole body fatigue.

You can also take it before hitting the gym, to prevent protein breakdown while training, but it might be overkill if you've already had a good pre-workout meal.

Sizes, Servings, And Scoop

Isopure Zero Carb is available in 3 different sizes, which each have their pros and cons. Buying a small tub might be best if it's your first time using isopure because you can see how the flavors sit with you. If you have the budget, then you can stock up and order less often by going for one of the larger sizes.

  • 1 lb (15 servings)
  • 3 lbs (44 servings)
  • 4.5 lbs (66 servings)

All sizes have the same scoop, which weighs 31 grams.

The Available Flavors

In total, there are 9 different flavors of Isopure Zero Carb. The one that we tried (Creamy Vanilla) had a weak, but pleasant taste to it. It wasn't bad by any means, but as someone who likes their protein shakes on the sweeter side, I decided to add in some almond milk, which made a noticeable difference in creaminess.

While it's not the best tasting protein shake we've tried, for the calories, we're not complaining. It's also free from aspartame and acesulfame potassium, which are two controversial artificial sweeteners. Isopure does, however, use sucralose for flavoring, which is something to bear in mind if you don't like that kind of thing.

How Does It Compare To Other Protein Shakes?

Isopure Zero Carb is one of, if not the lowest calorie supplement in the protein shake category. But how does it compare to the best of rest?

You can check out our chart below to find out, or click the link for our guide on which protein powder you should take


Our Rating









ISO 100




Nitro Tech




Overall Review

Overall, we feel that Isopure Zero Carbs is excellent for those seeking a low-calorie, high-protein option. As a pure whey isolate formula with over 20 vitamins and minerals, we rank it highly among the best in the business.

Considering it uses such pure ingredients, we think you will enjoy this product if you want a supplement without fillers, carbs, or sugar. While it won't melt the fat off your body by magic, it is an excellent companion for weight loss and cutting diets.

As a whey isolate, it is easier on the stomach than regular whey protein, which can make digesting it more comfortable.

We hope you enjoyed our isopure Zero Carb review, and hopefully, it gives you a better idea of what to go for in the future.

Isopure Zero Carb | Leanest Protein Shake

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Jonathan Abbott
Jonathan Abbott
Jonathan is a long time fitness enthusiast who specializes in helping others reach their goals faster with the most up to date sports science. When he's not working, you'll find him challanging his body with heavy squats and deadlifts.