How to choose a protein powder? The complete buyer's guide [2026]

What is protein and why does your body need it?

Protein is a macronutrient that the body uses as a building block for muscles, bones, skin, hormones, enzymes, and immune system cells. Unlike fats and carbohydrates, the body cannot store amino acids, which is why a regular intake of protein is essential.

Every protein is made up of a chain of amino acids. There are twenty in total, of which nine are essential—meaning the body cannot produce them itself and must obtain them from food (Ferrando et al., 2023). The content and ratio of essential amino acids determine the quality of a protein source. Among them, leucine plays a key role as it directly activates the mTOR signaling pathway, thereby triggering muscle protein synthesis (Garlick, 2005).

You can find protein in:

• meat,
• fish,
• eggs,
• dairy products,
• pulses,
• tofu, or
• nuts.

Protein supplements are not a substitute for a varied diet, but rather a practical tool for situations where you cannot cover your daily requirements through your normal diet—typically during periods of increased physical activity, while losing weight, or during a hectic daily routine (Jäger et al., 2017).

Amino acids and biological value

Biological Value (BV) indicates how efficiently the body can utilize protein from a given source and is a traditional indicator of protein bioavailability. While modern methods (such as PDCAAS or DIAAS) are used more frequently today, BV still serves as a good illustration of the differences between various sources. These sources differ significantly:

• Whey protein is among the sources with the highest biological value (a BV of around 104)
• Egg protein has a BV of 100 and is considered the reference standard
• Casein protein reaches a BV of 77
• Plant proteins generally have a lower biological value because they are often limited in one or more essential amino acids; for example, pea protein contains less methionine (Burke, 2010)

In practice, this means that when choosing a protein, it is not enough to just look at the total grams of protein per serving. It is equally important how much of that protein your body can actually use for building and repairing tissues.

Overview of protein supplement types

There are many types of protein powders on the market. Each has different properties, absorption rates, and uses. The following overview will help you understand the differences and choose the right protein for your situation.

Whey protein

Whey protein is derived from dairy serum, a byproduct of cheese production. It is the most popular and most studied type of protein supplement. It contains a complete spectrum of essential amino acids with a high proportion of leucine and is absorbed quickly, effectively stimulating muscle protein synthesis (Tipton et al., 2004).

Whey protein exists in three basic forms, which differ in their level of processing, protein content, and price.

Concentrate, Isolate, and Hydrolysate: The differences

Whey concentrate (WPC) typically contains 70–80% protein. The rest consists of fats, lactose, and minerals. It is the most affordable and usually the most palatable. For most athletes, it offers the best value for money.

Whey isolate (WPI) undergoes additional filtration (microfiltration, ion exchange), which increases the protein content to 90% or more. It contains minimal amounts of lactose and fat. It is suitable for people with mild lactose intolerance and for those who want to maximize protein intake while keeping caloric intake as low as possible, for example when losing weight.

Whey hydrolysate (WPH) is enzymatically pre-digested protein that absorbs the fastest. In practice, the difference in speed compared to isolate is relatively small, and the price is significantly higher. Hydrolysate typically has a bitter taste. For most athletes, it offers no significant advantage over isolate.

Casein protein

Casein makes up approximately 80% of the protein in cow's milk. Unlike whey, it coagulates into a gel in the stomach, which significantly slows down its digestion and absorption. This allows amino acids to be released gradually over several hours (Burke, 2010).

Slow digestion makes casein a popular choice before bed. A study by Res and colleagues (2012) demonstrated that consuming 40g of casein before sleep increases muscle protein synthesis throughout the night. Although newer research shows that whey stimulates nocturnal protein synthesis comparably (Trommelen et al., 2023), casein remains a practical classic due to its sustained amino acid release.

A systematic review by Trommelen and van Loon (2016) concludes that to reliably increase nocturnal muscle protein synthesis, it is advisable to consume approximately 40g of casein about 30 minutes before sleep. In combination with training, this strategy can contribute to greater muscle mass and strength gains (Snijders et al., 2015).

Multi-component protein

Multi-component proteins (also known as blend proteins) combine two or more sources of protein, most commonly whey and casein, sometimes supplemented with egg or plant protein. The goal is to leverage the benefits of different sources:

• Fast-absorbing whey for immediate stimulation of protein synthesis
• Slow-releasing casein for long-term amino acid supply

In practice, multi-component proteins are a versatile choice for those who do not want to worry about timing and are looking for one product for the whole day.

Plant-based proteins

Plant-based proteins provide a solution for vegans, vegetarians, and people with a milk protein allergy. They are most commonly made from:

• Pea (limited in methionine)
• Rice (limited in lysine)
• Soy (complete profile, but lower stimulation of MPS)
• Hemp (naturally contains omega-3 and fiber, but a less complete amino acid profile)
• Combinations of multiple sources (they complement each other)

Therefore, it is advantageous to choose products that combine multiple sources, as they complement each other, bringing the resulting amino acid profile closer to animal proteins (Young & Pellett, 1994).

Studies comparing dairy and soy proteins have shown higher acute stimulation of muscle protein synthesis with dairy protein (Wilkinson et al., 2007; Hartman et al., 2007).

In the long term, however, the differences are small: with a sufficient total dose and a combination of sources, plant proteins provide comparable gains in muscle mass and strength as animal proteins; the slight lead of animal proteins mainly applies to younger individuals (Lim et al., 2021; Messina et al., 2018). Soy performs comparably to dairy protein.

Beef and egg protein

Beef protein is produced by hydrolyzing beef collagen or muscle tissue. However, many products labeled as beef protein are actually made from hydrolyzed collagen. Therefore, it is worth checking the amino acid profile and the content of essential amino acids.

Egg protein is considered the reference standard for protein quality. It has a biological value of 100 and a complete profile of essential amino acids. It is suitable for people with milk protein intolerance who do not want plant-based protein.

Summary comparison table of protein types

How to choose a protein according to your goal

The best protein is the one that fits your specific goal—and that you enjoy drinking.

Protein for muscle growth and recovery

For maximum stimulation of muscle protein synthesis after training, two things are key: fast-absorbing protein and a high leucine content. Whey protein meets both conditions and is the top choice for this goal (Tipton et al., 2004).

How much protein post-workout? Moore and colleagues (2009) found that approximately 20g of high-quality protein after resistance training is sufficient to achieve maximum muscle protein synthesis stimulation in young men. The newer ISSN position stand (Jäger et al., 2017) recommends 20–40g of protein per serving, with the higher range intended for older athletes and scenarios where training involves large muscle groups.

What does the science say? A meta-analysis by Morton and colleagues (2018), which included 49 studies with a total of 1,863 participants, demonstrated that protein supplementation combined with resistance training leads to significant gains in muscle mass and strength. However, the positive effect began to plateau at a daily intake of around 1.62g of protein per kilogram of body weight.

Practical advice: Based on my practice, I can say that most clients achieve the best results with whey concentrate or isolate combined with high-quality nutrition. Protein is a supplement, not a foundation. Without proper training and an overall good diet, no protein will work miracles.

Protein and weight loss

When losing weight, protein is crucial for two reasons:

1. It helps maintain muscle mass in a caloric deficit
2. It increases feelings of fullness, making it easier to stick to a diet

The ISSN recommends a daily protein intake of 2.3–3.1g/kg of body weight for training individuals during caloric restriction to minimize muscle mass loss (Jäger et al., 2017). From a practical standpoint, the best options for weight loss are:

• Whey isolate (high protein content, minimum fats and carbohydrates)
• Casein (longer-lasting feeling of satiety)

Tip: Explore our guide to muscle definition.

Protein for overall health and vitality

Adequate protein intake is not just important for athletes. Muscle mass naturally declines with age (sarcopenia), which increases the risk of falls, fractures, and loss of independence. Regular intake of high-quality protein combined with physical activity is one of the most effective strategies to prevent this process (Burke, 2010).

Proteins are also involved in the production of antibodies and support tissue regeneration. For the general population that does not exercise at a competitive level, a daily intake of 0.8–1.0g of protein per kilogram of body weight is sufficient (Burke, 2010).

Who is a protein supplement suitable for?

Protein for beginners

If you are just starting with training and supplementation, you don't need to look for specialized products immediately. Whey concentrate from a reputable brand is the best choice for beginners: it has a favourable price, good taste, fast absorption, and a complete amino acid profile.

Practical advice: Beginners often wonder which protein to buy as their first. I recommend starting with one product, trying it for at least two weeks, and only then experimenting with other types. More important than the brand of protein is the overall quality of your diet and training consistency.

Protein for women

From a physiological perspective, there is no reason why women would need a different type of protein than men. Products labeled "protein for women" generally only differ by having a smaller serving size, different flavours, or added vitamins and minerals.

Tarnopolsky and colleagues (1990) found that women oxidize fewer amino acids during endurance exercise than men, suggesting that their protein requirements might be approximately 10–20% lower. For an active woman, an intake at the lower end of recommendations, i.e., approximately 1.4–1.6g/kg of body weight, is usually sufficient.

Protein during pregnancy and for children

Protein supplements are not automatically contraindicated during pregnancy, but their use should always be discussed with a doctor. Pregnant women have an increased need for protein, but this should primarily be met through whole foods.

The situation is similar for children and adolescents. Under normal circumstances, a varied diet should cover their protein needs. Administering protein supplements to children should always be under the supervision of a pediatrician or a nutritionist.

How much protein do you need daily?

Proper dosing is one of the most frequent questions. The answer depends on your body weight, type of activity, and goal. The following recommendations are based on the current ISSN position stand (Jäger et al., 2017) and other sources.

The distribution of protein throughout the day is also important. Jäger and colleagues (2017) recommend dividing daily intake into servings of 20–40g, evenly distributed approximately every 3–4 hours. Each dose should contain 700–3,000 mg of leucine (Jäger et al., 2017).

Research by Tarnopolsky and colleagues (1992) showed that protein intake significantly exceeding requirements (e.g., 2.8g/kg/day vs. 1.8g/kg/day) did not lead to greater muscle mass gains, but only to increased amino acid oxidation. In other words: "more" does not automatically mean "better".

Practical example: A man weighing 80kg who does resistance training three times a week needs approximately 112–160g of protein per day (1.4–2.0g × 80kg). If he gets 90g from a normal diet, he can comfortably supplement the remaining 22–70g with one or two servings of a protein shake.

When to use protein: Timing throughout the day

Post-workout protein

The post-workout period is traditionally considered the most important window for protein intake. After resistance training, amino acid transport into the muscle increases, and muscle protein synthesis remains elevated for at least 24 hours after training (Biolo et al., 1997; Jäger et al., 2017).

A study by Tipton and colleagues (2001) showed that administering essential amino acids along with carbohydrates before training led to higher amino acid utilization than post-workout. However, Jäger and colleagues (2017) state in the ISSN position stand that the benefit of protein exists both when taken before and after training, and the exact timing is more a matter of individual preference.

Practical advice: Treat yourself to a serving of protein (20–40g) within two hours after training—feel free to use a protein shake. If you ate a full meal containing protein 2–3 hours before training, it is not necessary to worry about post-workout protein immediately.

Pre-workout protein

Protein before training can be particularly beneficial if:

• You train on an empty stomach (e.g., in the morning)
• More than 3 hours have passed since your last meal
• The workout will be long or intense

In such a case, a dose of 20–30g of protein approximately 30–60 minutes before training ensures that you have enough amino acids available for ongoing protein synthesis.

Nighttime protein

A nighttime dose of protein is one of the best-supported strategies for optimizing recovery:

• Res and colleagues (2012) demonstrated that 40g of casein consumed immediately before bed was successfully digested and absorbed even during sleep and led to increased muscle protein synthesis overnight.
• Snijders and colleagues (2015) showed that regular consumption of protein before sleep combined with resistance training over 12 weeks led to greater muscle mass and strength gains.
• Trommelen and van Loon (2016) confirmed that ~40g of casein taken approximately 30 minutes before sleep effectively stimulates protein synthesis throughout the night.

The ideal choice for a nighttime dose is casein protein in an amount of ~40g, taken approximately 30 minutes before bed.

Protein in the morning and between meals

A protein shake is a quick way to supplement your protein—a convenient breakfast or snack option, especially on hectic days. It is not a replacement for a full meal, but in situations where you might otherwise not eat at all, protein is significantly better than nothing.

Protein vs. gainer vs. BCAA: What is the difference?

These three categories of supplements are often confused, even though they serve different purposes.

BCAA vs. protein: Current scientific knowledge suggests that with sufficient intake of high-quality protein (which naturally contains BCAAs), BCAAs as a standalone supplement provide no proven additional benefit for muscle protein synthesis (Jäger et al., 2017). If you are already consuming enough protein (1.4–2.0g/kg/day), you likely do not need standalone BCAAs.

Gainer vs. protein: For the majority of the population, including recreational athletes, a gainer is unnecessary and can lead to unwanted fat gain. A gainer only makes sense if you have an objective problem with getting enough calories and are struggling to gain weight even with an increased food intake.

What to look for when choosing: Label, composition, price

How to read a protein supplement label

When choosing a protein, focus on these 5 key pieces of information on the label:

1. Protein content per 100g of powder (not per serving, as serving sizes vary between products). High-quality whey concentrate: at least 70g/100g. Isolate: over 85g/100g.
2. Amino acid profile, especially leucine content. Goal: at least 2–3g of leucine per serving (the ISSN recommends 700–3,000mg per serving; Jäger et al., 2017).
3. Ingredient list. The shorter, the better. Standard: protein, emulsifier (lecithin), flavouring, sweetener. Be wary of products with a long list of unknown ingredients.
4. Fat and carbohydrate content. Low content of both is generally desirable, especially during weight loss.
5. Certification (Informed Sport, NSF). Products tested by an independent third party offer a guarantee of quality and absence of contamination.

Sweeteners in proteins

The most common sweetener in protein supplements is sucralose. It is intensely sweet, contains no calories, and is considered safe by the European Food Safety Authority (EFSA) at normal intake levels.

Another common alternative is stevia (steviol glycosides), a natural plant-based sweetener. Stevia can have a slightly bitter aftertaste, which is why it is sometimes combined with sucralose.

For those who want to avoid sweeteners entirely, there are unflavoured (natural) variants of protein. These can be mixed with fruit, cocoa, or honey according to your own taste.

Taste, solubility, and preparation

Taste and solubility are subjective but important factors. No matter how high-quality the protein is, it won't help you if you don't want to drink it. Before buying a large pack, I recommend trying a single sample or a small pack.

Protein with milk or water?

How to mix protein correctly? You will achieve the best results using a shaker with a mixing ball. First, pour in the liquid (200–300ml), then add the protein powder and shake thoroughly. Doing it the other way around often leads to powder clumping at the bottom.

Check out our shaker and bottle category and find your new favourite protein shaker.

Allergies, intolerances, and special diets

Your choice of protein is also influenced by health restrictions and dietary habits:

• Milk protein allergy: Avoid all dairy proteins (whey and casein). Suitable alternatives include plant-based proteins, egg protein, or beef protein.
• Lactose intolerance: Whey isolate contains only trace amounts of lactose and is usually well tolerated. If even isolate doesn't work for you, opt for lactose-free variants or plant-based proteins.
• Vegan diet: Choose combined plant-based proteins (e.g., a mixture of pea and rice protein) that provide a complete amino acid profile. Plant-based proteins can provide comparable support for muscle protein synthesis, provided that an adequate intake of all essential amino acids and a sufficient total dose are ensured (Lim et al., 2021).
• Gluten-free diet: Most protein powders do not contain gluten, but always check the label. Some multi-component products may contain cereal-based additives.

Common myths about proteins

"Protein damages the kidneys." In healthy individuals with normal kidney function, there is no scientific evidence that higher protein intake (within the ranges recommended for athletes) damages the kidneys. This is confirmed by data from large-scale studies (Burke, 2010). However, people with pre-existing kidney conditions should consult a doctor regarding protein intake.

"The more protein, the more muscle." Research clearly shows that beyond a certain threshold (approximately 1.6g/kg/day for most athletes), further increases in intake do not lead to greater muscle mass gains, but only to increased amino acid oxidation (Tarnopolsky et al., 1992; Morton et al., 2018).

"Expired protein is dangerous." The "best before" date on protein powder is a guideline. Dry protein powder retains its properties even after the date has passed if stored correctly (in a dry, cool place with the lid tightly closed). The key is that the powder should not smell bad or have a changed colour or consistency. However, if you have any doubts, it is better to throw the product away.

"A protein shake fully replaces a meal." Protein powder is a dietary supplement, not a meal replacement. It lacks the fiber, majority of vitamins and minerals, healthy fats, and phytochemicals that you get from whole foods.

Practical summary: 5 steps to choosing the right protein

1. Define your training goal. Do you want to build muscle, lose weight, or simply supplement your protein intake? The goal determines the type of protein and the dosage.
2. Choose the protein type. For muscle growth and recovery → whey concentrate or isolate. For weight loss → whey isolate. Before bed → micellar casein. For vegans → combined plant-based protein.
3. Check the composition. Look at the label for protein content per 100g, leucine content, ingredient list, and carbohydrate/fat content.
4. Respect your restrictions. Consider allergies, intolerances, and preferences (veganism, lactose-free diet).
5. Try it and evaluate. Start with a smaller pack—e.g., samples—verify the taste and tolerance, and only then buy a larger pack.