Whey protein, the most popular kind of protein powder, is naturally rich in branched chain amino acids (BCAAs). Your body needs these molecules to build proteins and support everything from your skin to your muscles. While there are plenty of great plant-based and vegan protein powder options out there, whey naturally has far more BCAAs, according to Jim White, R.D., owner of Jim White Fitness and Nutrition Studios.
Here’s why that matters: BCAAs—especially one called leucine—are like a signal that tells your muscles it’s time to grow and repair. Whey protein is naturally rich in BCAAs, which is one reason it’s been a gym bag staple for decades. Whether you’re lifting weights, running, or just trying to stay active as you age, those amino acids do a lot of heavy lifting behind the scenes.
Even then, though, your search isn’t over. Glance from tub to tub of whey and you’ll notice many read either ‘whey protein concentrate’ or ‘whey protein isolate.’ So what’s the difference?
Though both wheys sport benefits, one may better suit your personal nutritional needs and fitness goals. Whey protein isolate is processed further than whey protein concentrate in order to remove the carbohydrates, fats, and lactose that occur naturally in whey protein, says White. “While whey concentrate is about 70 to 80 percent protein, whey isolate is more like 90 to 95 percent protein,” he says. (Good to know: Since whey isolate requires more processing to reach the protein’s purest form, it tends to be more expensive than concentrate.)
To put that in real-world terms: if you’re looking at a 100-calorie serving, you’d get around 23 grams of protein from isolate versus about 18 grams from concentrate. That might not sound like a huge gap, but it can add up if you’re tracking your macros closely or taking multiple shakes a day.
What About Absorption?
One thing you might be wondering: does your body actually use these proteins differently? The short answer is that isolate can digest a bit faster for some people, and whey in general tends to show up in the bloodstream relatively quickly. That’s because there’s less fat and carbs slowing things down. Concentrate absorbs a little more gradually, which isn’t necessarily a bad thing (more on that in a minute).
Concentrate May Be Best For You If…
You exercise regularly and simply want to add a protein shake to your daily routine. (Unless you’re lactose intolerant, that is. Lactose is not filtered out of whey concentrate, White says.)
Whey concentrate contains about five more grams of fat and carbs than whey isolate, and with these few extra grams come beneficial nutrients like conjugated linoleic acids (CLAs). “CLAs, which are found in meat and dairy, are healthy fats that can help to decrease body fat,” explains White.
The extra carbohydrates in whey concentrate create more of an insulin spike than the very few carbs (or complete lack of carbs) in whey isolate. Your insulin actually helps you transport protein into the muscles faster, says White, making a whey concentrate shake a great post-workout drink.
You’re Just Getting Started
If you’re new to fitness or just beginning to incorporate protein shakes into your routine, concentrate is often the smart choice. It gives you everything you need to support muscle growth and recovery without the premium price tag. Research shows that both concentrate and isolate produce similar muscle-building results when you’re hitting your daily protein goals—so don’t feel like you’re missing out by going with the more affordable option.
You’re Watching Your Budget
Let’s talk dollars and cents. Whey concentrate is usually the more budget-friendly option, while isolate tends to cost more because it’s more filtered and higher in protein by weight. That savings can really add up, especially if you’re using protein powder daily.
Here’s a simple trick: you can take a slightly larger scoop of concentrate to match the protein content of a smaller isolate serving—and still come out ahead financially. For most people working out a few times a week, that’s a win-win.
You Want Those Extra Nutrients
Concentrate isn’t just about protein. Because it’s less processed, it keeps more of the good stuff that naturally occurs in whey:
- Immunoglobulins and lactoferrin – these support your immune system
- Minerals like calcium, magnesium, and phosphorus – great for bone health
- Bioactive compounds – helpful little extras that get filtered out in isolate
Think of it this way: concentrate is closer to whole milk in its nutritional profile, while isolate is more stripped down. Neither is “better”—it just depends on what you’re looking for.
Isolate May Be Best For You If…
The thought of drinking milk gets your stomach rumbling, you’re on a strict calorie diet for weight loss, or you follow a low-carb or ketogenic (high-fat) style of eating. “If you watch your macronutrients (fat, carbs, and protein) really closely or are taking multiple servings of whey per day, the fat and carbs in concentrate can add up,” White says.
You’re Lactose Sensitive
Here’s something that might surprise you: about 65 percent of people worldwide have some degree of lactose intolerance. If you’re one of them, isolate is usually your best bet. The intense filtration process removes most of the lactose—we’re talking less than 1 gram per serving in most isolates, compared to around 3.5 grams in concentrate. Some isolates are extremely low in lactose, but amounts vary by brand—so it’s worth checking the label if you’re sensitive.
That said, if you only have mild sensitivity, you might tolerate concentrate just fine. It’s worth experimenting to see what works for your body.
You’re Counting Every Calorie
When you’re trying to lose weight while keeping your muscle, every calorie counts. An isolate serving is often a little lower in calories than concentrate, but the exact numbers depend on the formula—so check the label.
Plus, with isolate you’re getting more protein per calorie—so you’re maximizing your protein intake while minimizing everything else. That’s especially helpful if you’re:
- Following a ketogenic or very low-carb diet
- In a cutting phase for bodybuilding
- Tracking macros down to the gram
- Trying to create a calorie deficit without sacrificing protein
You Want Fast Post-Workout Fuel
If you’re the type who wants to chug a shake right after your last set, isolate might edge out concentrate here. Because it’s so low in fat and carbs, your body can get to work absorbing those amino acids right away. You’ll hit peak blood amino acid levels within about an hour—perfect for that post-workout recovery window.
That said, White points out that the carbs in concentrate actually help with protein transport too, so both options work well after a workout. It really comes down to your personal preferences and goals.
How Much Protein Do You Actually Need?
Here’s where things get interesting. You might have heard that 25 to 30 grams of protein per meal is the ‘max’—but it’s more accurate to say that muscle-building benefits tend to level off per meal, depending on your size and training. While that’s a reasonable guideline, newer research suggests it’s not quite that simple.
“Some protein powders boast 60 grams of the muscle-building macro, but research suggests our bodies can only absorb about 25 to 30 grams per meal,” says White. So don’t just pick the powder that has the most protein.
What research does show is that 20 to 25 grams of protein is the sweet spot for triggering muscle protein synthesis—that’s the process where your muscles actually grow and repair. After a really intense, full-body workout, you might benefit from closer to 40 grams. But loading up on 60 or 70 grams in one sitting? Your body probably won’t use all of that for muscle building.
The bigger picture matters more: aim for about 1.6 to 2.2 grams of protein per kilogram of body weight throughout the day. Whether that comes from concentrate or isolate, you’ll get similar muscle-building results as long as you’re consistent.
Reading the Label Like a Pro
Then, take a look at the ingredient list. “Go for a whey protein powder that contains fewer than five to seven ingredients,” White adds. The shorter the ingredient list, the better.
Here are a few more things to watch for when you’re shopping:
Watch Out for “Proprietary Blends”
Some protein powders list “proprietary blend” on the label without telling you exactly how much isolate versus concentrate is in the mix. This can be tricky because a product might advertise “whey protein isolate” on the front but actually contain mostly concentrate. Look for products that clearly state the amounts of each type.
Check for Third-Party Testing
With all the protein options out there, quality matters. Look for products that have been tested by independent labs—certifications like NSF Certified for Sport or Informed Choice are good signs. This is especially important given ongoing concerns about supplement quality across the industry—so third-party testing is a smart thing to look for. The Vitamin Shoppe’s proprietary brands go through 320 quality assurance steps and are verified by independent third-party labs, so you know what you’re getting.
Consider the Extras
Some protein powders add helpful ingredients like digestive enzymes to help with absorption, or they might include creatine for an extra performance boost. These can be convenient if you’re already planning to take those supplements anyway.
Making Your Choice
At the end of the day, both whey concentrate and whey isolate are excellent protein sources that can help you reach your fitness goals. The “best” one is simply the one that fits your:
- Budget – Concentrate is more affordable
- Digestive needs – Isolate is better for lactose sensitivity
- Dietary approach – Isolate works well for strict macro counting
- Training intensity – Both work great for post-workout recovery
If you’re still not sure which is right for you, the Health Enthusiasts at The Vitamin Shoppe are trained to help you find the best fit. You can also book a free virtual nutrition coaching session to get personalized guidance based on your specific goals.
The bottom line? Don’t overthink it. Grab a protein that fits your lifestyle, hit your daily protein targets, stay consistent with your workouts, and you’ll see results—whether you choose concentrate, isolate, or even switch between the two depending on your needs.