When choosing a protein powder, the thing that trips people up most is the flavor. No matter how good the nutrition label looks, if you don't enjoy drinking it every day, the powder just sits at the bottom of the bag until it expires.
This time I bought a 1kg bag of REYS Whey Protein in the Cafe au Lait flavor - a product supervised by popular Japanese fitness YouTuber Hiroaki Yamasawa - and finished the whole thing. Here's my honest take on both what I liked and what bothered me. I'll add short explanations for the technical terms as we go.
What Is REYS Whey Protein?
First, the basics.
- Product: REYS Whey Protein, Cafe au Lait flavor, 1kg
- Supervised by: Hiroaki Yamasawa (popular fitness YouTuber)
- Manufacturing: Made in Japan
- Type: WPC (Whey Protein Concentrate)
- Price: roughly in the 4,000-yen range for 1kg (varies by retailer and sales)
Per 30g serving, it provides 21.8g of protein, 117.3kcal, 3.5g of carbohydrates, and 1.8g of fat. It also contains seven types of vitamins.
"WPC" refers to one method of extracting protein from whey (the liquid left over when cheese is made from milk). Whey protein commonly comes in two forms, WPC and WPI (isolate). WPC tends to be more affordable and keeps more of the natural dairy flavor.
The flavor lineup includes Cafe au Lait, Chocolate, Mixed Berry, Yogurt, Royal Milk Tea, Orange, Grape, and Salted Caramel - eight in total. I went with the perennially popular Cafe au Lait.
The Cafe au Lait Flavor Is "Sweet Coffee Milk"
My first impression was exactly that: sweet coffee milk.
The coffee bitterness is very restrained, more of an aroma than a taste. If you're expecting the bitter edge that black coffee fans enjoy, it isn't there. Instead, the sweetness comes through clearly, closer to the bottled coffee milk you'd find at a corner shop or a carton of sweetened coffee.
How you feel about that sweetness will vary a lot by person. I actually liked it because it felt like a reward after training, but if you dislike sweet drinks, it may feel a bit heavy.
As for getting tired of it, I made it through the full 1kg without any trouble. That said, if it had been a 3kg bag, I probably would have gotten bored somewhere in the second half. That's my honest read.
Mixability Is Excellent
This exceeded my expectations. Put water in the shaker, add the powder, shake about ten times, and it's fully mixed. Clumps (lumps of powder that fail to dissolve) were barely an issue.
With cheaper WPC products, you often get powder settling at the bottom and hitting your mouth as a gritty lump at the end. With REYS, that concern is essentially gone. It also doesn't foam excessively, and less residue sticks to the inside of the shaker, which makes cleaning easier - a small but genuinely appreciated detail.
Water vs. Milk Changes the Experience Considerably
Same powder, completely different drink depending on what you mix it with.
With water, it's refreshing and light, closer to iced coffee. Good if you don't want to add calories. The sweetness comes through directly though, so if you skimp on the water it can feel a little cloying.
With milk, it gets much closer to an actual cafe au lait, as the name suggests. It's smoother and more satisfying, and it's clearly the better-tasting option. But milk adds calories and fat, so be careful if you're cutting.
I settled into using water right after training and milk when drinking it as a snack replacement.
Where Does 72.7% Protein Content Sit?
21.8g of protein per 30g serving works out to about 72.7%. That number may not mean much to beginners, so here's some context.
Protein content ratio simply means what percentage of the total powder is protein. The rest is carbohydrates, fat, plus sweeteners and flavorings that make it taste good. WPC-type products generally land somewhere around 70-80%, so REYS at 72.7% sits comfortably in that standard range.
In other words, a fair assessment is "not exceptionally high, but nothing lacking for a WPC." If maximizing protein content is your top priority, other types like WPI exist, though they tend to cost more. I'd describe REYS as a product that balances taste, price, and protein content.
What Seven Vitamins Actually Do for You
The seven included are vitamin B1, B2, B6, C, D, niacin, and pantothenic acid.
This isn't a case of "drink it and get healthy." It's simply a nutritional supplement that lets you top up vitamins that tend to be lacking in a normal diet, as a side benefit.
The practical upside, I think, is that it cuts down on buying and managing separate supplements. Keeping a multivitamin on hand and remembering to take it daily is surprisingly hard to sustain. If it's already in the protein you drink every day, that's one less thing to manage. That reduction in hassle may be the most practical value of the seven-vitamin blend.
An Honest Word on Price, Value, and the Price Increase
The 4,000-yen range for 1kg is the going rate now. I want to be upfront here: there was a time when REYS could be had for 3,000-something yen. Rising raw material costs and similar factors have pushed the price band up, so anyone who remembers the old price will definitely notice.
That said, actual selling prices vary quite a bit depending on where and when you buy. The same 1kg bag can differ by several hundred to over a thousand yen between retailers and sale periods, so it's well worth comparing a few shops before buying.
Even so, given that the entire protein industry has seen price increases, a product made in Japan with seven vitamins and a strong reputation for taste still feels like decent value. Its position today isn't "dramatically cheap" but rather "reasonable for what you get."
1kg Is an Easy Size to Finish
It sounds minor, but this was a big plus.
At 30g per serving, that's roughly 33 servings. One shake a day means you'll finish it in a little over a month. Protein powder tends to clump once it absorbs moisture after opening, so finishing at this pace is safer than dragging a bag out for ages.
More importantly, the damage is small if the flavor doesn't suit you. Only those who've bought a huge bag and hated it know that particular despair. If you're trying it for the first time, starting with 1kg is unquestionably the right call.
Honest Drawbacks and Who It Might Not Suit
I've praised it a lot so far, so here's what genuinely bothered me.
1. The sweetness is strong, so opinions will differ The Cafe au Lait flavor leans clearly sweet. If you buy it expecting a lightly sweetened, bitter coffee taste, it will definitely not match your image.
2. As with all WPC, lactose can be a concern for some This isn't specific to this product but general knowledge about WPC as a category. Because of how it's made, WPC retains relatively more lactose (a sugar found in milk). People who get an upset stomach from milk - what's commonly called lactose intolerance - may experience something similar with WPC-type products. If that sounds familiar, a WPI type with drastically reduced lactose is the safer choice.
3. It's not outstandingly cheap After the price increase, it isn't "overwhelmingly cheap" anymore. If your goal is to minimize cost per gram above all else, it may not be your optimal pick.
Who I'd Recommend It To, and Who Should Skip It
Recommended for
- Protein beginners who want to start with a flavor that's hard to dislike
- People who like sweet drinks and value that post-workout reward feeling
- Anyone who prioritizes easy mixing and easy shaker cleanup
- Anyone who finds managing a separate vitamin supplement annoying
Probably not for
- People who prefer lightly sweetened, bitter-leaning flavors
- People with a tendency toward lactose intolerance who react to dairy
- People who want the highest possible protein content (consider WPI or another type)
- People who want to push cost per gram as low as possible
Summary
After finishing the full 1kg, my overall take is: "if you can accept a sweet flavor, this is a very satisfying bag." Mixability exceeded expectations, the flavor is well executed, it includes seven vitamins, and it's made in Japan. At 72.7%, the protein content is standard for a WPC, and even after the price increase, the cost feels within a range I can accept.
On the other hand, the strength of the sweetness and the lactose issue inherent to WPC are things to know in advance. If either of those gives you pause, you'll likely be happier looking at a different flavor or a different type.
"Try 1kg first, and keep buying it if it works for you." REYS makes that decision easy, which is one of its strengths. If you've been curious, starting with the Cafe au Lait flavor is a perfectly reasonable move.