Nothing in your cart

Uh oh! Your cart is empty 😢

One of these products might be what you're after...

No recent items

Whey Protein Isolate

Bulk Nutrients Whey Protein Isolate (WPI) is ultra-high in protein and is sourced from grass fed cows.

4.8 from 5817 reviews. .


Earn at least 129 Whey Cool Points

Lactose Free

Gluten Free Ingredients






Value for Money

Pay in four fortnightly installments when your order is over $100.

Price Per Bag

1kg = $43.00

2kg (2 x 1kg) bags = $41.50 each
3kg (3 x 1kg) bags = $40.67 each
4kg (4 x 1kg) bags = $40.25 each
5kg (5 x 1kg) bags = $39.20 each
10kg (10 x 1kg) bags = $38.70 each



Package Size


Customers also bought

Bulk Nutrients' Pre Workout Non Stimulant powder the quiet achiever and great alternative when compared to high powered stim based pre workouts
313 reviews
View Details
Bulk Nutrients' Joint Complex suffering from painful joints Joint Complex can do wonders for you
116 reviews
View Details
Bulk Nutrients' Arginine Alphaketogluterate (AAKG) powder is 100% pharmaceutical grade helping create a pump effect in the gym
73 reviews
View Details
Bulk Nutrients' Whey Protein Isolate Sample Pack are perfect for when you're travelling
359 reviews
View Details
Bulk Nutrients' Amino Acid Flavourings makes raw aminos tastier
149 reviews
View Details
Bulk Nutrients' Branched Chain Amino Acids BCAAs Unflavoured 100% pharmaceutical grade and are unflavoured for maximum purity
182 reviews
$22.00 - $49.00
View Details
Bulk Nutrients' BCAA Recovery have countless studies showing benefits in reducing muscle soreness
1401 reviews
View Details
Bulk Nutrients' Pre Workout 101 certified to crush workouts offers sustained energy more focus and no crash
1587 reviews
View Details
Bulk Nutrients' L Glutamine powder offers many benefits including muscle recovery supporting a stronger immune system and helping to prevent muscle wastage
646 reviews
$19.00 - $38.00
View Details
Bulk Nutrients' Cognitone will have you feeling switched on when you need it most
121 reviews
View Details

Highest Protein

Taken post workout

Low fats & carbs

Whey Protein Isolate (WPI) Protein Powder

Bulk Nutrients' Whey Protein Isolate (WPI) comes from grass-fed, hormone (rbST) free cows. It is a low-temperature cross and ultra-filtered whey protein which remains completely undenatured.

Buy Whey Protein Isolate Online

We believe it is one of the purest Whey Protein Isolates on the market, with high levels of protein and lower levels of fats, carbohydrates and sodium.

Our Whey Protein Isolate is naturally rich in amino acids, particularly branched chain amino acids (BCAAs) and essential amino acids (EAAs) which support optimum muscle growth in conjunction with a healthy diet (, ).

Why should you use Whey Protein Isolate (WPI)?

Bulk Nutrients' WPI is an exceptionally pure protein source, with much of the fat and lactose normally found in Whey Protein Concentrate filtered out.

  • WPI is fast absorbing and can help build lean muscle ()
  • Taken post workout, WPI assists in recovery ()
  • WPI can help to increase protein synthesis
  • Whey Protein Isolate can help to boost the immune system ()
  • Bulk Nutrients WPI is low in fats and carbs and has a negligible lactose content

Bulk WPI Lovers

Want to get featured with your tasty Bulk WPI? Tag us with #bulknutrients on Insta and we'll do the rest.

A great selection of WPI flavours on offer...

Bulk Nutrients uses only the strongest sweetener available in our flavoured Whey Protein Isolate, which ensures an exceptionally pure finished product.

With flavours on offer like Chocolate Whey Protein Isolate, Vanilla WPI, Banana Whey Protein Isolate, Choc Ice Cream Whey Protein Isolate, Choc Honeycomb WPI and Salted Caramel Whey Protein Isolate to name a few.

And, because we use the strongest flavours available, we only need to include them as a fraction of the overall product which ensures an exceptionally pure WPI from Bulk Nutrients.

WPI vs WPC, which is better?

WPI and WPC come from the same source, here are the benefits they both offer.

  • WPI and WPC are both rapidly absorbing proteins
  • Both WPI and WPC are great to consume after training ()
  • They both contain minimal fats and carbohydrates per serve
  • Both offer a great range of delicious flavours

The main difference... WPI is a more refined version of WPC and because of this offers significantly less lactose per serve.

So, if you are very sensitive to lactose and can’t live without whey, or after a higher protein hit then give WPI a go!

WPI stacks well with other supplements in shakes...

Bulk Nutrients’ WPI is great to have in a protein shake with other muscle building and performance-based supplements. We believe it is best used with...

So if you want the fastest absorbing and most bioavailable protein source, choose Bulk Nutrients WPI.

Fast shipping on Whey Protein Isolate

At Bulk Nutrients, we offer $9 flat rate shipping and express postage for all orders 3.5kgs and under. Orders travelling to New Zealand go by Express Post up to 2kg.

It's a very regular occurrence for Bulk Nutrients customers in capital cities to order one afternoon and have their order on their doorstep the following morning!

Bulk Nutrients’ WPI is an all round protein

Whey Protein Isolate (WPI) is an all round protein source, so it caters for everyone from endurance athletes to strength athletes.

WPI is great to aid recovery, strength and muscle levels as well as boost the immune system.

Looking for a quick and easy high-protein breakfast then have a look at High Protein Overnight Oats. Or you might like to check out our other Salted Caramel / Choc Honeycomb flavoured proteins

Directions & Ingredients

WPI Dosage

Dosage size - 30 grams (approx. 1 flat scoop) of WPI
Dosage size - 30 grams (1 scoop) of WPI

30 grams (approximately 1 flat scoop) after training for maximum nutritional benefit, or anytime during the day for a low fat snack replacement or to boost your protein intake. For the greatest accuracy, we recommend following our guide here.

Directions for Whey Protein Isolate

Combine powder with 300-400ml of water or low fat milk and consume immediately.

WPI Ingredients

Ingredients: Whey Protein Isolate (Milk), Flavouring, Sweetener (Sucralose).

Contains: Milk.

Note: Chocolate based flavours contain cocoa. Salted Caramel contains salt. Raw does not contain any flavours or sweetener. Choc Peanut is nut allergen free (no actual nuts in the flavouring, synthetic flavours) still has dairy allergens.


Keep well sealed, protect from moisture, light and heat.

Frequently Asked Questions about WPI

How does Whey Protein Isolate taste?

WPI is flavoured and is generally considered to have a pleasant taste.

What is made from?

Whey Protein Isolate is a protein derived from milk.

Are samples available of this product?

Yes, you can request a free sample of Whey Protein Isolate from our Free Sample page.

How is it packaged?

Bulk Nutrients' Whey Protein Isolate is packaged in resealable 1kg pouches.

Can I purchase WPI in smaller sizes?

Yes - WPI is also available in single-serve sachets which we call WPI Sample Packs.

Is the packaging for this product recyclable?

In theory yes, but not in all council areas right now.

The REDcycle program has been discontinued, and the industry is working together to find a solution to continue recycling soft plastics. For now, we recommend checking with your local council, but most require you to put the packaging in your regular landfill bin.

The included scoop can be recycled as hard plastic in your local council pickup.

For more information about what Bulk is doing to improve sustainability, check this article.

Can I receive a discount buying more than one of this product at once?

Absolutely! Price breaks for Whey Protein Isolate begin when you purchase 2 units of any flavour. Just add more than that to your cart to see the savings.

Can children have Whey Protein Isolate?

If your child needs a protein supplement, we suggest grabbing some KidActiv which is specifically designed for kids and is available in delicious Choccy Milk and Vanilla Sundae.

Whey Protein Isolate Lab Testing Results

At Bulk Nutrients we take our products’ purity very seriously.

To maintain our Whey Protein Isolate’s consistent high quality, we send a cross-section of our product range to certified Australian laboratories for testing, such as Biotest, National Measurement Institute and Southern Cross University which are all independently verified and NATA accredited.

The NMI is a laboratory run by the Australian Government, which is used for police forensic testing, SIA - Sports Integrity Australia drug screening and by multinational food manufacturers for quality and safety testing.

NMI has conducted many hundreds of tests on Bulk Nutrients products for more than 6 years.

Lab testing results for Whey Protein Isolate (WPI)

WPI Nutrition Panels

Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4841,612
Protein (g)25.685.5
(saturated) (g)0.31.1
Carbohydrates (g)1.34.5
(sugars) (g)0.31.0
Sodium (mg)55182.8
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4811,602
Protein (g)26.688.5
(saturated) (g)0.20.7
Carbohydrates (g)0.92.9
(sugars) (g)0.20.8
Sodium (mg)54179
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4811,604
Protein (g)26.688.8
(saturated) (g)0.20.8
Carbohydrates (g)0.82.7
(sugars) (g)0.20.7
Sodium (mg)54179
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4831,611
Protein (g)25.284.0
(saturated) (g)0.31.1
Carbohydrates (g)1.86.0
(sugars) (g)0.31.0
Sodium (mg)54179
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4821,607
Protein (g)26.688.5
(saturated) (g)0.20.7
Carbohydrates (g)0.93.0
(sugars) (g)0.41.4
Sodium (mg)54179
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4731,577
Protein (g)26.086.8
(saturated) (g)0.10.2
Carbohydrates (g)1.03.3
(sugars) (g)0.20.6
Sodium (mg)54181
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4921,640
Protein (g)27.090.0
(saturated) (g)0.31.0
Carbohydrates (g)0.72.4
(sugars) (g)0.20.6
Sodium (mg)47156
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4791,595
Protein (g)26.387.8
(saturated) (g)0.20.7
Carbohydrates (g)1.03.2
(sugars) (g)0.30.9
Sodium (mg)122406
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4811,603
Protein (g)26.487.9
(saturated) (g)0.20.7
Carbohydrates (g)1.13.6
(sugars) (g)0.20.7
Sodium (mg)53177
Servings per 1kg package: 33Serving size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Energy (kj)4801,601
Protein (g)25.886.1
(saturated) (g)0.20.7
Carbohydrates (g)1.65.4
(sugars) (g)0.41.3
Sodium (mg)53177
Servings per 1kg package: 33Servings size: 30g
Average Quantity Per ServingAverage Quantity Per 100g
Alanine (mg)1,3794,597
Arginine (mg)7262,420
Aspartic Acid (mg)3,02310,077
Cysteine (mg)9673,223
Glutamic Acid (mg)4,25714,190
Glycine (mg)4351,450
Histidine (mg)4841,613
Isoleucine (mg)1,5245,080
Leucine (mg)3,45911,530
Lysine (mg)2,7099,030
Methionine (mg)5801,933
Phenylalanine (mg)9193,063
Proline (mg)1,0883,627
Serine (mg)1,0883,627
Threonine (mg)1,2824,273
Tryptophan (mg)5801,933
Tyrosine (mg)1,0163,387
Valine (mg)1,3544,513

About Whey Protein Isolate

Whey Protein Isolate (WPI) is considered the industry standard for dairy protein quality and is made during the cheese making process. As it’s the most highly refined version of whey protein, Whey Protein Isolate has the highest level of protein and the lowest level of fats and carbohydrates.

Containing only traces of lactose, it is easily digestible and can be enjoyed by those with sensitive stomachs. Whey Protein Isolate has high levels of branched chain amino acids and essential amino acids, with a thorough spread of conditional and non-conditional amino acids.

Whey Protein Isolate FAQs

Why is Whey Protein Isolate the best choice?

Whey Protein Isolate has the highest biological value of any protein source and WPI is the most processed and purest form of Whey Protein.

WPI contains around 1% fats, 1% carbohydrates and around 90% of protein. As it is rapidly absorbed, it is ideal post workout, especially when training in a fasted state.

Is Whey Protein Isolate lactose free?

Whey Protein Isolate contains small amounts of lactose which usually means it is suitable for lactose sensitive individuals. People with complete lactose malabsorption may still have trouble tolerating the lactose in whey protein isolate.

Comparatively though WPI contains very little lactose, at approximately 0.3 grams per serve it has forty times less lactose than a glass of milk.

Does Whey Protein Isolate contain gluten?

Gluten is not naturally occurring in any of the ingredients in our Whey Protein Isolate, though we do process other gluten containing ingredients in our facility.

How many serves of WPI should I have each day?

The answer here will depend on your weight, energy levels and goals.

Most athletes and active people aim to consume 2 grams of protein per kilogram of bodyweight per day. For an 80kg person, this equals 160 grams of protein. Two WPI shakes a day would contribute 52g of protein to this total, leaving approximately 108 grams of protein to be consumed through general food sources.

Protein from protein shakes should be one of multiple protein sources you consume, not the only one.

What is the standard dose of WPI powder?

30 grams is the generally accepted standard dose of WPI protein powder, as this yields between 25 and 28 grams of pure protein.

How long after a workout should I have WPI?

For optimal recovery and muscle growth, it’s generally recommended to take Whey Protein Isolate within 20-60 minutes after exercise.

Why is WPI better than eating tuna, meat or drinking milk?

Like other powdered protein sources, WPI is great value for money and can be very convenient.

With a long shelf life (usually up two years), WPI is extremely stable and can be stored, carried and consumed easily unlike a tin of tuna or steak.

WPI contains only trace amounts of fats and carbohydrates, as opposed to most high protein foods which contain these in higher amounts.

How soon should I drink WPI after mixing it with water?

While WPI is very stable in powdered form this changes when mixed with water. Once mixed with water, WPI should be consumed within an hour. It can last more than 24 hours once blended with water if refrigerated.


  1. Wolfe RR. Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?. J Int Soc Sports Nutr. 2017;14:30. Published 2017 Aug 22. doi:10.1186/s12970-017-0184-9 -
  2. Pal, S., & Ellis, V. (2010). The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men. The British journal of nutrition, 104(8), 1241–1248. PMID: 20456814 -
  3. Naclerio F, Larumbe-Zabala E. Effects of Whey Protein Alone or as Part of a Multi-ingredient Formulation on Strength, Fat-Free Mass, or Lean Body Mass in Resistance-Trained Individuals: A Meta-analysis. Sports Med. 2016 Jan;46(1):125-137. doi: 10.1007/s40279-015-0403-y. PMID: 26403469 -
  4. Cintineo HP, Arent MA, Antonio J, Arent SM. Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training. Front Nutr. 2018;5:83. Published 2018 Sep 11. doi:10.3389/fnut.2018.00083. PMID: 30255023 -
  5. Ha DJ, Kim J, Kim S, Go GW, Whang KY. Dietary Whey Protein Supplementation Increases Immunoglobulin G Production by Affecting Helper T Cell Populations after Antigen Exposure. Foods. 2021 Jan 19;10(1):194. doi: 10.3390/foods10010194. PMID: 33477967; PMCID: PMC7835905 -
  6. Kreider RB, Campbell B. Protein for exercise and recovery. Phys Sportsmed. 2009 Jun;37(2):13-21. doi: 10.3810/psm.2009.06.1705. PMID: 20048505 -
  7. Cooper, R., Naclerio, F., Allgrove, J. and Jimenez, A., 2021. Creatine supplementation with specific view to exercise/sports performance: an update -

Whey Protein Isolate Reviews

Popular Posts from the Bulk Blog

With over 700 recipes and articles, the Bulk Nutrients Blog has something for everyone! Find a new workout, meet our ambassadors or take a deep dive into our products today.

Compare all Bulk Nutrients proteins

Popular Proteins

Popular Products

Popular Categories

About Bulk Nutrients

We're an Australian manufacturer and supplier of high quality sports supplements.

Operating since 2008, Bulk Nutrients has become one of the premier Australian brands to supply nutritional products to top level athletes, competitors and those on a journey to a healthier lifestyle.

Find out more about Bulk.

Contact Bulk Nutrients

One thing that sets Bulk Nutrients apart is that we love to talk to our customers!

Whether you need product advice, help with the website or need a change made to your order... call us on +61 3 6266 4725.

If you prefer email you can email us day or night at

For online chat, hit the 'Chat' button in the bottom right hand corner of your screen and you'll be connected to one of our lovely customer service team.

Or if you'd like to get in touch through our online contact form, that's cool too!

Follow us on Social Media

Bulk Nutrients on FacebookCheck out Bulk Nutrients' Instagram postsView Bulk Nutrients' TikTok contentView Bulk Nutrients' YouTube Channel



We acknowledge the Traditional Owners of the land on which our organisation operates, the Melukerdee People of the South East Nation and pay our respects to Elders past, present, and emerging.

Bulk Nutrients is proudly
Australian owned and operated.

7 Crabtree Road, Grove, Tasmania, 7109.
ABN: 17 158 981 447

Terms & ConditionsSustainability StrategyPrivacy PolicyPayment InformationSitemap

All prices are in Australian dollars (AUD) and include GST unless otherwise stated.
All content copyright © Bulk Nutrients 2008 - 2024