Isopure is a protein brand that's marketed as keto-friendly, and which is manufactured by a company called Glanbia Performance Nutrition. The company describes their protein powder line as "Pure & Simple," and offers low-carb and zero-carb options.
But does Isopure provide an effective protein dose for muscle building? Does the brand use any questionable additives? Is regular whey protein zero-carb? And how do real Isopure customers rate and describe the effects of this product line?
In this article we'll answer all of these questions and more, as we analyze the ingredients in two of Isopure's most popular protein powders to give our take on whether or not they're likely to be effective for muscle building, and whether or not they're healthy.
We'll review Isopure Protein Drink and Isopure Zero Carb Protein Powder.
We'll also feature unsponsored customer reviews, discuss whether regular whey protein contains carbs, and provide a cost comparison to show which retailers sell Isopure for the best prices.
Key takeaways:
- Unflavored protein powder is effectively formulated
- Protein drink is unhealthy in our opinion
- We do not currently recommend Isopure
Ingredient Analysis — Zero Carb Protein Powder
The ingredients in Isopure Zero Carb Protein Unflavored are shown below:
This protein powder provides 25 grams (g) of protein per serving, which is an effective dose.
A 2018 medical review suggests that around 25 g of protein post-workout or more provides maximal benefit for muscle building.
Soy lecithin is an emulsifier that should be safe and non-toxic.
We generally prefer single-ingredient protein powders, as soy lecithin is a "processed" ingredient, and there is no information on the whey protein sourcing on Isopure's product page (we consider animal products sourced from pastured animals to be healthier).
The unflavored version of the Isopure protein powder is the only one we consider somewhat healthy.
The flavored versions contain a number of inactive ingredients we consider unhealthy, such as artificial flavors, artificial colors and synthetic vitamin and mineral additives.
Ingredient Analysis — Protein Drink
The ingredients in the Grape Frost flavor of Isopure Protein Drink are shown below:
Whey protein isolate is included at a 32 g dose, which is effective for muscle building.
There are a number of inactive ingredients in this formulation that we consider to be unhealthy.
Phosphoric acid is clinically shown to be associated with low blood calcium levels.
Natural and artificial flavor are categorical descriptors that fail to identify the specific flavoring chemicals.
We consider artificial flavor to be particularly unhealthy, as some artificial flavors were shown to be toxic to animal cells in a clinical trial published in the Brazilian Journal of Biology.
Sucralose is an artificial sweetener shown to cause negative changes to insulin function in healthy, young adults, as we documented in our review of another protein brand called Seeq.
Red 40 and Blue 1 are artificial food dyes, and a 2020 meta-study on artificial food dyes and health stated the following:
"Artificial dyes have neurotoxic chemicals that aggravate mental health problems."
Overall, we consider Isopure Protein Drink likely to be effective for supporting muscle growth, but we don't currently recommend this product from a health perspective due to the inactive ingredients discussed above.
Real People Try Isopure
A TikTok creator named Karla shares her experience using Isopure's protein powder:
@karlagonzalezxo An honest and chaotic review on Isopure infusions protein powder #isopureinfusion #isopureinfusions #isopureinfusionsmixedberry ♬ Chill Vibes - Tollan Kim
A TikTok creator named Eric Marinez shared his thoughts on the taste of Isopure Protein Drink:
@eric_marinez 🍹#isopureprotein #protein #foryou #share ♬ original sound - Eric Marinez
Isn't Most Whey Low-Carb?
Isopure's marketing centers on its low-carb and zero-carb options, which is a somewhat strange value proposition in our opinion, given that whey protein isolate has low or zero carbs in most supplements.
Consider the Nutrition Facts label below from Nutricost Whey Protein Isolate:
This supplement provides only 1 g of carbs per serving, but also provides more protein and calories per serving.
For individuals on a ketogenic (keto) diet, perhaps it's worth paying extra for Isopure to save that 1 g of carbs per serving, but it's a substantial price premium.
Isopure Zero Carb Protein Powder currently costs $79.99 for 47 servings, or $1.70 per serving.
Nutricost Whey Protein Isolate currently costs $72.95 for 65 servings, or $1.12 per serving.
Since whey protein isolate should be functionally equivalent between brands, budget-conscious consumers may want to consider other whey protein isolate brands than Isopure.
Our Clean Protein Picks
MBG Whey Protein Isolate+ is our top overall protein powder.
Whey protein is a "complete" protein, meaning it contains all nine essential amino acids.
Anthony's Organic Hemp Protein is our top vegan protein pick.
It's extremely nutrient-dense, providing 25% of the Daily Value (DV) of iron and 8% of the DV of potassium.
Both of the products recommended in this section are free of ingredients that we consider to be unhealthy.
Customers Rate Isopure
Amazon is a better resource for honest customer reviews than a brand's website in our opinion.
Isopure Zero Carb Protein Powder has been reviewed over 44,000 times at the time of updating this article, with an average review rating of 4.5 out of 5 stars.
The top positive review from a verified purchaser comes from a user named "AnnieK" who gives the product a 5/5 star rating, and who likes the taste:
"This is my go-to protein powder. No protein powder tastes good, including this one, but this one tastes better than all other protein powders. I would almost willingly drink this if I weren't using it for protein."
The top negative review from a verified purchaser is written by a user named "The Nagars" who gives the product a 1/5 star rating, and who claims it caused side effects:
"Neither my wife nor I have any allergies or any sensitivities to food. We both had intense abdominal pain and explosive diarrhea every time we drank this. The funny thing is that we honestly didn’t realize that the culprit was this protein shake we were sharing until I got really sick."
Isopure Zero Carb Protein Powder currently has an average review rating of 4.4 out of 5 stars on Google.
Where to Get the Best Price
Isopure products are sold at a variety of online retailers.
Here's a price breakdown for a one-time purchase of the two products reviewed in this article, at the time of publishing:
Isopure Protein Drink (12-pack)
Brand website: $59.99 (plus shipping, link)
Vitamin Shoppe: $54.99 (free shipping, link)
Amazon: $54.99 (free shipping, link to official Amazon listing)
Isopure Zero Carb Protein Powder (47 servings)
Brand website: $79.99 (free shipping, link)
Amazon: $74.26 (free shipping, link to official Amazon listing)
Walmart: $69.83 (free shipping, third-party seller, link)
Isopure protein supplements are currently around 10% cheaper on third-party retailers than at the brand's website.
However, the Walmart listing is from a third-party seller, so it may be safer to purchase Zero Carb Protein Powder from the official Amazon listing or the brand's website.
Isopure Pros and Cons
Here are the pros and cons of Isopure in our opinion:
Pros:
- Zero Carb Protein Powder has no unhealthy ingredients
- Zero Carb Protein Powder is only keto protein powder we've come across
- Both products reviewed have effective protein dose for muscle building
- Mostly positive online customer reviews
Cons:
- Somewhat expensive per serving
- Protein Drink contains artificial flavors
- Protein Drink contains artificial colors
- Protein Drink contains an artificial sweetener
- Doesn't appear to be clinically tested
- Unclear if brand sourced from grass-fed animals
