If you watch any reality TV show on MTV, you’ll likely be visually attacked by a Protein World advert. Its in-your-face advertising makes one thing clear: If you have ambitions of being an orange celebrity with a huge Instagram following, this is the whey protein for you. Today I’m bringing you an in-depth Protein World…

Written by Russ Howe PTI, and most recently updated 1 day ago.

14 min read

If you watch any reality TV show on MTV, you’ll likely be visually attacked by a Protein World advert.

Its in-your-face advertising makes one thing clear:

If you have ambitions of being an orange celebrity with a huge Instagram following, this is the whey protein for you.

Today I’m bringing you an in-depth Protein World Slender Blend review to determine whether the hype is justified, or whether this product fails to compete with the industry top dogs.

Along the way, we’ll discuss a number of funny as hell things Slender Blend has been through on its crazy journey so far…

(If nothing else, this supplement has been controversial as a motherf**ker.)

Protein World Slender Blend

Protein World Slender Blend Review – The Good

There is one very clear good point with Slender Blend, it hits the sweet spot for muscle protein synthesis.

Studies show that consuming a serving of 20 grams of protein will provde almost the same anabolic response as a dose twice its size, and the 22.9g we get here is in the right ball park to do the job for us. (1)

how much protein after workout
protein world slender blend nutrition review

Protein World Slender Blend – The Bad

Wait a minute… that’s it for the good points?!

Yes, it’s going to be one of those reviews…

I know a lot of you guys enjoy it when I rip a product apart using the latest science and common sense, rather than the fake “5 star reviews” you see in Google (#advertisement), so you’re in for a treat today!

The problems began with Slender Blend before we even purchased it.

The Protein World website is heavy on very pretty images of trendy guys and gals, but light on science. This is the first red flag, we had to dig pretty deep in order to find the nutritional information and formula breakdown for Slender Blend.

Perhaps the company aren’t expecting their target audience to look for it (more on this later), but I take it as a sign of a product which is hiding something.

Alongside the 22.9 grams of protein (which is great), we get 7.9 grams of carbohydrates and 2 grams of fat.

For a supplement primarily targeted towards the weight loss market, that’s a fairly hefty carbohydrate content in each shake, the vast majority of which is pure sugar.

Obviously this has been done to sweeten the taste of Slender Blend, but with so many great tasting shakes on the market offering fewer carbohydrates per serving, Slender Blend struggles to compete.

protein world slender blend

Next up it’s my golden rule for whey protein supplements; the all-important protein-per-serving ratio…

You’re likely buying a whey protein supplement because you want to get more protein into your diet, so a good product will have in the region of 75% (or more) protein-per-serving.

Slender Blend comes in at just 60% protein-per-serving, meaning a huge 40% of your scoop isn’t protein.

With its rather high price tag (£60 for a 2kg tub), I was also expecting the Slender Blend formula to be very competitive, but sadly we get a cheap combination of ingredients which simply doesn’t deserve the cost.

If we really want to drill down and maximize muscle growth, we’ll see a blend of hydrolized whey protein isolate, whey protein concentrate, egg protein, casein, and/or soy to spike maximum muscle protein synthesis. (2)

Sadly, we get basic whey protein concentrate in Slender Blend.

(Yes, the cheapest form of whey protein to manufacture…)

When comparing it to similarly priced whey protein supplements like this, the Slender Blend formula gets comprehensively squashed.

Finally, we arrive at the proprietary blend of vitamins and so-called ‘fat burners’…

Throwing in these ingredients allows supplement manufacturers to make big, bold claims about the fat loss benefits associated with their product, but they do very little in terms of actual fat loss.

For example, caffeine has previously been linked with fat burning benefits, so including it in a product means that they can use slogans like “Improves fat loss!” in the marketing of the supplement.

What they don’t say, of course, is that the benefits were so small they were considered statistically insignificant, and would require a much larger dose than the one contained in the product.

But that’s business, folks!

A proprietary blend is another piece of fitness industry bulls**t. Basically, a company is within their legal rights to list the ingredients of a formula without the dosages.

Now, imagine paying to see a movie with your favourite star on the poster only to find out he/she is only in it for two minutes.. you’d be f**king raging, right?

A proprietary blend works in much the same way.

The product may contain caffeine, but it could be in such a small amount that you don’t see any of its benefits.

It’s a fitness industry loophole which most reputable supplement manufacturers have moved away from using in the last 10 years, in favor of a more honest, transparent approach, but Protein World continue to do it.

Of course, regardless of being hidden behind a proprietary blend or not, the fat burning ingredients are barely effective anyway.

For example, green tea extract is often hyped as a fat burner, however it will not make any difference unless consumed in absolutely ridiculous amounts. Even then, the results are tiny and depend on the person being caffeine naive. (3, 4, 5)

The other key ingredient hailed as a fat burner in Slender Blend is guarana extract. But again, there is no research to show it promotes fat loss. Guarana does have caffeine inside it, but you’d need a super-high dose to see any effects at all. (6)

As we can see, the elevated price tag of Slender Blend doesn’t appear to have a direct correlation with the quality of the product, which leaves me with one question…

protein world slender blend review

Who Are Protein World And Why Are They Everywhere?

If you follow Khloe Kardashian, you’ve likely already encountered Protein World before.

The company has been incredibly smart with their marketing. Light years ahead of their competitors, in fact.

By partnering with reality TV stars, they have cornered their niche of the fitness industry and established themselves in just a few short years.

If you’re don’t keep up with the Kardashians, however, you likely know Protein World from the advert shown below.

protein world slender blend review

Back in 2015, this bright yellow billboard was splashed all over London, and is remembered as the ad which started the whole body shaming movement.

Heck, I get it.

As a tanned, skinny blonde glares down with almighty smugness, the slogan “Are You Beach Body Ready?” punches like a blow from Mike Tyson, making women everywhere feel self-conscious about the pressure of summer looming around the corner.

Body shaming is something which has become increasingly worse since then, too, with a growing number of men also feeling pressured to look ‘perfect’.

It was subsequently voted “Worst Ad of the Year”.

But it got even crazier for Protein World…

Their CEO decided the best way to deal with the public backlash was to claim “the only people offended by our advert are feminist terrorists (!!) who are insecure about their own bodies.”

Cue madness!

Actually, cue genius marketing tactics.

The increased publicity this advert created elevated Protein World from run-of-the-mill overpriced supplement company (which it is) to national level supplement brand, and profits rose by £2 million.

All publicity is good publicity, as they say.

This is a marketing style Protein World have fiercely stuck to since then, because it works for them.

Protein World Khloe Kardashian

Khloe Kardashian is an ambassador for Protein World?

If anything, that should be a f**king deterrent! This is the same Khloe Kardashian who’s TV coach advised her to put butter in coffee to burn more fat

But for Protein World, it works.

This is not the first time a celebrity has endorsed a product, and it’s actually a much better match than we usually see.

For example, can you remember when Bono advertised credit cards? Gwyneth Paltrow has literally made a second career selling woo. Or, my personal favourite, Hulk Hogan flogging grills.

It looked like he had no idea why he was there.

protein world reviews

Getting that pairing of celebrity and product is very hard to do, but it can almost guarantee success if the balance is right.

For example, Arnold Schwarzenegger partnered with MusclePharm in 2015 and released a line of bodybuilding supplements.

They absolutely sucked.

I repeat:

Arnold Schwarzenegger. Bodybuilding supplements. F**king sucked.

Sales were still through the roof, however, (because Ah-nuld) and the line quickly became MulsclePharm’s best sellers.

He was the perfect fit for that product, and they knew it.

khloe kardashian protein world slender blend

My point being, Khloe Kardashian may not be the pinnacle of fitness industry cutting edge information, but she is perfect for Protein World because they are targeting a very specific niche.

They’ve doubled down on this approach, working with scores of annoyingly orange Instagram influencers and contestants on reality TV shows like Geordie Shore and Love Island. to push their products at their legions of followers.

Sure, they might occasionally say nonsense like “I think vegans are cruel for drinking water, because that’s a fish’s house”, or give completely bulls**t dieting advice which lands them in hot water. But for the most part, it works.

protein world slender blend
“Trust me, I’m orange.”
protein world the slender blend review

Misleading Claims Everywhere

Alongside the bulls**t advice which goes hand-in-hand with essentially hiring social media influencers are your sales team, the Protein World website itself is a minefield of weight loss myths.

Before we get stuck into that, we must look at a considerably larger issue…

Back in 2016, The Sun reported that Slender Blend was found to contain a whopping 17x more carbs than advertised.

Holy f**k! 17 times!

Way to treat customers like a giant bag of d**ks!

Instead of the 2.2g per 100g claimed, it contained 38.5g! Protein was also down from the claimed 70g (per 100g) to just 50g.

To make matters worse for Protein World, the product was tested twice, to the same outcome.

“The declared nutrition information was outside acceptable tolerances of accuracy which is potentially misleading.”

– Jon Griffin, Kent Scientific Services (who carried out the tests).

The repercussions could be serious, with the company now being investigated by Trading Standards, who had this to say:

“The company is committed to complying with legal ingredients, health claims, and labeling standards. Should Protein World fail to do so, we will seriously consider all legal enforcement options.”

– Trading Standards
protein world slender blend review

Sadly, they didn’t learn from this…

In 2018, the Advertising Standards Agency quite literally forced Protein World to remove several misleading weight loss claims from their website and products.

This included incorrect or unproven statements about the effectiveness of CLA, ketones, and other ingredients.

A total of nine issues were investigated by the ASA, and all of them were upheld.

protein world scandal

Misleading claims continue to run rife through the website, though.

Using their products will apparently give you “a firmer bum, a slimmer tum, and leaner thighs”.

Otherwise known as spot reduction, which is impossible. (7)

The hype runs strong throughout Slender Blend’s surrounding product line, most notably ‘Toner’ capsules which, despite hinting at fat loss in the product name, are merely a mixture of creatine monohydrate and a multivitamin blend.

Both ingredients are way under-dosed, but they do seem pleased to tell us it’s gluten free…

Whatever next… gluten free Facebook?

There’s even time for one of my favourite fitness buzzwords to make an appearance; detox.

Yes, it appears the Protein World boffins have developed a capsule which is able to detox your body of nasty toxins and cleanse your soul of the evil powers of rock n’ roll…

… ignoring the fact that no detox product has ever been shown to work. Ever. (8)


We also get silly claims that you can lose up to 4lbs per week as a result of using Slender Blend as a meal replacement shake.

Yes, the good old meal replacement line…

Whenever a supplement manufacturer recommends customers begin replacing actual food with their product, all credibility flies out of the window.

The clue is in the name; a whey protein supplement is there to supplement your food, not replace it.

The reason I dislike meal replacement recommendations is because a) the company just wants you to use more product, and b) they’re about to drop some insanely bad dieting advice on you…

Cue insanely bad dieting advice:

“Replace two meals with Slender Blend shakes!”

With each shake being 150 calories, a moderate sized lunch would see many people drop under the dreaded 1000 calories per day threshold.

No s**t you’re losing weight! You’re f**king starving!

As mentioned earlier, I’ve never been a fan of meal replacement shakes. But if we want to be picky (and you know I do), the well-received Channel 4 program SuperShoppers conducted a trial in 2018 comparing the performance of Protein World Slender Blend against three other meal replacement products.

Despite the fact Slender Blend was (by far) the most expensive product, it came bottom of the study results.

To make matters even more hilarious devastating, this was a blind study; meaning the participants didn’t know which products they were using.


Ultimately, this is all just misleading advertising from a company who have a history of misleading advertising.

protein world slender blend review

Protein World Slender Blend Review – Final Verdict

It’s crunch time…

I’m about to finalize my Protein World Slender Blend review by running it through my supplement rating system.

It’s deliberately harsh, and no supplement has ever received full marks.

But first, I’m gonna tell you a little story…

When I was a kid, I picked up The New Encyclopedia of Modern Bodybuilding, by Arnold Schwarzenegger.

Sure, it might be a little dated now, but that book taught me the foundations of lifting weights and laid out the principles of proper nutrition and hard training.

It was a game changer for me.

Nowadays, however, many kids look up to orange social media celebrities who’d be more qualified to teach you about taking a selfie than setting a PR.

And this is the exact niche Protein World aim their products towards.

Forget the forward strides made by the awesome Jessica Ennis-Hill at the London Olympics, teaching women to focus on being strong, not skinny… Protein World appear to represent a throwback to the dark old days, where body shaming is cool and the number of likes you received on your last IG post determines how happy you are inside.

Our youth has it tough.

Fixed that for ya.

Its popularity is largely down to its marketing as a status symbol (being able to be part of the ‘in crowd’ on Insta), rather than its quality.

As a whey protein supplement, Slender Blend is severely lacking.

I was originally going to finish my review with the award of 1 star but, given the ongoing nutrition label scandal, it becomes the first supplement to receive zero stars.

See the product here. If you’re looking for a much more solid whey protein supplement, try this one instead.

protein world slender blend honest review


  1. Moore, D. R., et al. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. (2009)
  2. Paul, G. L., et al. The rationale for consuming protein blends in sports nutrition. J Am C Nutr. (2009)
  3. Hursel, R., et al. The effects of green tea on weight loss and weight maintenance: a meta-analysis. Int J Obes (Lond). (2009)
  4. Westerterp-Plantenga, M.S. Green tea catechins, caffeine and body-weight regulation. Physiol Behav. (2010)
  5. Diepvens, K., et al. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. Am J Physiol Regul Integr Comp Physiol. (2007)
  6. Rodrigues, M., et al. Herb-Drug Interaction of Paullinia cupana (Guarana) Seed Extract on the Pharmacokinetics of Amiodarone in Rats. Evid Based Complement Alternat Med. (2012)
  7. Perry, E. Targeted Fat Loss: Myth or Reality? Yale Scientific. (2001)
  8. Blachford, A., et al. The Voice Of Young Science brings you; the detox dossier. (2009)

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I’m Russ. I’ve been a personal trainer since 2002, and I own russhowepti.com.

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