Guide to Buying Whey Protein Powder in Japan

Whey protein is easily absorbed by the body and relatively affordable. Buying whey protein powder in Japan, however, can be challenging. Navigating a huge product range, understanding labeling, quality certifications, and voiding artificial or synthetic sweeteners is often frustrating. Save your time and energy as we review some of the top whey protein shakes in Japan including additive-free. Our labeling and protein guide will also help you choose products more easily for yourself.

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Whey Concentrate vs Whey Isolate

Supplement whey powders can use whey concentrate (WPC), whey isolate (WPI), or both. Whey concentrate is just less processed so it has more fat and cholesterol. The body also absorbs it more slowly, and for these reasons it’s often a good choice for young athletes, resistance training,  or as a post workout protein supplement.  

Whey isolate has less fat and sometimes zero cholesterol. It’s more processed and therefore pricier. It’s digested and absorbed more quickly. WPI is a good choice for a pre-workout protein or taken between competitive events. It’s a good choice for a fat restricted diet or those with poor metabolism.

Some whey protein powders combine these two slightly different types of whey for maximum training outcomes. Both types of whey are generally okay for lactose intolerance. For more sensitive stomachs, a plant based protein powder, egg protein powder, or bone broth powder may be the better choice. 

Grass Fed Whey Protein Powder

Grass fed whey protein powder tends to be pricier. It may have a slight nutritional edge over the standard variety, but it is a more ethical choice. The key advantage is that grass-fed whey protein powders hardly ever contain artificial sweeteners or other synthetic additives. You can select from WPC and WPI varieties, but the flavor range is not so extensive.

Read our guide on grass fed whey protein made in Japan

Fortified Protein Powders with Vitamins and Minerals

Many manufacturers have a range of whey proteins to choose from. The ‘basic’ or ‘standard’ ranges are usually just about the protein. Fortified or enriched proteins come in two categories. Those that focus on B-complex vitamins for protein synthesis and improved metabolism, and those that often include all 11 key vitamins and additional minerals. The latter often go by as Weight Down, Weight Up, or Diet Protein.

See our full guide to fortified whey proteins

Health Risks of High Protein Intake

When you take a protein supplement, always make sure to drink extra water because protein has a dehydrating effect. Protein also increases acidity in the body, so you should balance higher protein intake with alkalizing fruits and vegetables. 

Additives in Whey Protein Powders 

A hidden danger in protein supplements is all the other stuff (other than protein) that goes into them. These the artificial flavorants, sweeteners, and bulking agents or emulsifiers. When buying whey protein powder in Japan, it can be difficult navigating ingredient listings, but we help you with our labeling guide below.

Different Types of Sweeteners in Protein Powder

The most controversial additives are artificial sweeteners such as sucralose (E955) / スクラロース, and the ‘tames’ such as aspartame (E951), acesulfame potassium or potassium-K (E950) / アセスルファムK, neotame (E961), or advantame (E969). For the more health conscious, you may want to avoid these as they are associated with gut ailments.

Monk fruit or lo han guo / ラカンカ, is one of the best non nutritive natural sweeteners. It doesn’t increase blood sugar levels, and allergic reactions are rare. The most commonly used natural sweetener is stevia / ステビア. It has some drawbacks and you should avoid stevia that is not 95% steviol glycoside.  

Other sweeteners are sugar alcohols. Two commonly used ones are xylitol / キシリトール and  erythritol / エリスリトール. Sugar alcohols can cause bloating, cramping, or diarrhea in some people. Xylitol, on the other hand, is not so bad but is mostly used in toothpastes and chewing gum to reduce cavities and improve oral flora. 

Emulsifiers and Bulking Agents in Whey Protein Powder

Emulsifiers and bulking agents 乳化剤 (nyukazai) give the protein powder more bulk, and prevent granules clumping together. They also produce better viscosity when mixed with water or milk. If the power contains soy lecithin, check to see if it’s GMO-free.

Maltodextrin is also common. This processed carbohydrate can give you an quick energy boost, but also spikes insulin levels a lot. Maltodextrin has been linked to digestive disorders, and may also come from genetically modified foods such as corn. 

Product Certifications

In a highly competitive market worth billions, you may want to check that your whey protein is worth the cost. Many Japanese whey protein powders now carry globally recognized certifications. The most popular is Informed Choice. Alternatively, manufacturers will display their own independent testing results or will at least guarantee a 100% amino score [アミノ酸スコア100] meaning the protein isn’t bulked with non-essential amino acids.

Understanding Whey Protein Powder Labeling in Japan

Japanese products often list nutrients in grams and milligrams which can be difficult to understand if you’re used to US daily value (DV) percentages.

However, unless fortified, whey protein powder doesn’t contain much in the way of micronutrients other than calcium (around 10% DV) and minimal amounts of iron and potassium.

WPC proteins can vary widely in cholesterol or fat content. Whey Protein Isolate (WPI) tends to have minimal or zero amounts of fat or cholesterol. 

Other Labeling Keys

A key term is 人工 (jinkou) meaning man-made or artificial. In combination with 甘味料 (kanmiryou) you get 人工甘味料, or artificial sweetener. Likewise 人工香料 (jinkou-kouryou) is artificial flavoring. Sometimes you see the word 合成 (gosei) meaning synthetic as in 合成甘味料 (synthetic sweetener).

Another keyword is and 保存料 (hozonryou) / preservatives. The term 添加物 (tenkabutsu) indicates additives in general. All the better if the above are affixed by terms such as 不使用 (fuyou) / no used or 無添加 (mutenka) / not added – [人工甘味料不使用].

GMO information is usually just in katakana as in GMOフリー / GMO-free, or sometimes they might use the kanji as in 遺伝子組み換えなし(idenshikumikae-nashi) or using the terms 不使用 or 無添加. The word 乳化剤 (nyukazai) indicates emulsifiers.

Checklist for Choosing the Best Whey Protein Powder in Japan

Unless otherwise stated, most protein powders will be WPC.

Check if your protein powder is enriched with extra vitamins or minerals.

Confirm the type of sweetener used. Unflavored varieties usually have no sweetener.

Note protein grams per serving (18-24g is a good for training), number of servings per pack, and match this to your budget. 1 kg usually lasts about a month. A glass of milk can add 8g of protein. 

Nutritional values may vary where natural flavors like chocolate and cocoa are used.  

Check for product certifications or any independent lab results.

 A 100% amino score means the powder isn’t spiked with non-essential amino acids.

See our complete protein guide

1. Limitest Ultra – best value additive-free WPC powder
2. Fine Lab Whey Protein – best pure whey isolate
3. Ultora Diet Protein – best WPC-WPI vitamin enriched protein
4. Explosion Whey Protein – best value bulk buy
5. LohaSports – best priced grass fed whey series
6. High Clear Whey 100 – best original whey protein series
7. beLegend – best winning flavors for a whey protein

Limitest Ultra – best value additive-free Whey Protein Power

Limitest is manufactured in Japan from milk powder sourced from the USA. The protein BCAA count is 5.3g valine, 9.4g leucine, and 5.8g isoleucine per 100g. This works out to 7.2g BCAA per 35g serving, which is pretty good. The fat and carbohydrate count is similar to most other WPC proteins. The plain version is considerably cheaper than the flavored ones.

Reasons to Reconsider

Although the best choice for an affordable straight up whey powder, with no added emulsifier it doesn’t mix as smoothly as regular powders. It can be a bit bubbly and clumpy if you don’t use a whisk or shaker. If this doesn’t bother you, then the taste is not bad and it’s a good choice for a smoothie.

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Fine Lab – best pure whey isolate

Fine Labs is one of the best high-quality whey protein powder manufacturers in Japan. Their protein is sourced from grass fed cow herds which are carefully monitored for milk quality free from hormones and antibiotics.

The isolate is obtained through cross flow micro filtration – a two tier ceramic filtration method with no chemical processes or ion exchange. The benefit is an intact protein with significantly less sodium and fat. Manufactured products undergo a yearly independent quality control audit.

Reasons to Reconsider

The only drawback is all 11 flavored versions contain sucralose, while the unflavored is additive-free. As a grass-fed whey isolate, it’s costlier than other options. However, the plain version comes in additional 2kg and 4kg bulk packs and the protein content is as much as 95.4%.

See more choice for WPI protein powders

Ultora Diet Protein – best WPC-WPI vitamin enriched whey powder

Ultora is a small Tokyo-based brand producing additive-free protein powders. The ‘diet protein’ concept is due to reduced fat content by combining WPC and WPI to a B-Vitamin complex with Vitamin-C for energy and protein synthesis. The highest values are Niacin and Pantothenic acid – important coenzymes for protein, carbohydrates, lipids, and cholesterol. Vitamin-C is an anti-oxidant and important coenzyme for collagen production.

The fat and carbohydrate content is still more than Fine-Labs, however, the combination of WPI and WPC produces a longer and more sustained synthesis of the whey protein into amino acids for the body. This may result in longer hunger cessation and more energy released by the body for amino synthesis.

Reasons to Reconsider

There are not many demerits to this protein powder especially considering that WPC/WPI mixes are not that easy to come by in Japan. Ultora also one of the best enriched or ‘complete’ protein powders free of artificial additives. The price point is in range of similar quality protein powders.

See more choice for fortified protein powders

X-plosion Whey Protein – best value bulk buy

X-Plosion is a popular Japan whey protein powder for avid gym goers and muscle trainers. You can easily get 3kg packs and the plain flavor has no additives, including soy lecithin. The 100% amino scores mean the protein is not bulked with non-essential amino acids, and the product is also certified by the anti-doping agency.

Reasons to Reconsider

This is an affordable high-quality protein, but some people may have issue with the additives in the flavored versions. Sweetener mixes differ between the flavors, but all have sucralose.

Cafe au lait: sunflower lecithin emulsifier and sucralose; strawberry: soy lecithin emulsifier and sucralose; fruits au lait: soy lecithin, stevia, and sucralose; chocolate milk: cocoa powder, soy lecithin, sucralose, and stevia; plain: sunflower lecithin only.

LohaSports – best priced grass fed whey series

LohaStyle is a Japan food manufacturer focused on sugar restricted natural foods that carry organic JAS certification. For a flavored grass-fed whey protein, these are some of the best priced. Their three original flavors – plain, chocolate, and macha – recently won a 2022 Monde Selection Grand Gold Quality Award for their excellent taste. They now also have a strawberry flavor.

Reasons to Reconsider

LohaSports protein do use an emulsifier, so they may not mix and dissolve as easily as proteins with additives. Also, good quality grass-fed whey tends to be foamy which is an indicator of high bio-activity. It’s best, therefore, to let your shake settle for a while and hand-mixing is recommended.

Learn more about LohaSports proteins

See more choice for grass-fed whey proteins

High Clear Whey 100 – best original whey protein series

High Clear is the main protein brand by F-Assist corporation, an Japan whey and soy OEM protein manufacturer. The company is based in Sendai and many of their protein powders are enriched with fossilized Okinawa coral powder.

This formula contains a full spectrum of 11 vitamins and 74 minerals – but more so in trace amounts. The B-vitamin complex is typically half that of an average vitamin-enriched protein, but the amount of Vitamin-C is quite comparable. A number of flavors include a milk creaming powder for better mixing and taste.

Reasons to Reconsider

This Whey 100 series has a range of light and fruity flavors, but all contain artificial sweeteners: 甘味料（スクラロース、アスパルテーム・L-フェニルアラニン – generally a combination of sucralose and aspartame. The plain version, while sweetener-free, is still fortified with Okinawa coral powder. Their WPI-90 Water Protein series uses stevia.

Learn more about High Clear proteins

beLegend – best winning flavors for a whey protein

beLegend is a hip and vibey Japan brand legendary for their tasty and original whey protein flavors. Flavors include varieties such as passion fruit, tropical pine, cola, or lime, and this series has won numerous international taste awards. They keep things simple with just around 1.1g of Vit-B6 and 34g of Vit-C. Vitamin-B6 is a coenzyme for amino acid synthesis and catabolism and Vit-C for collagen production.

Reasons to Reconsider

For a protein powder certified by Informed Choice for ingredient statements, and a winner of so many taste wards, there’s not much to fault this protein powder on. If you’re adverse to synthetic sweeteners, then you will have to give beLegend a skip because even the plain flavor uses sucralose.

Prefer a protein bar instead? See our best selection!