Protein powder enables people to quickly and easily consume protein, and there are varieties on the market to match almost every dietary preference, food allergy, or flavor inclination.

But as Robert Wildman, Ph.D., RD, co-author of the textbook "Sports and Fitness Nutrition," says in his article "How to Pick the Perfect Protein Powder," "Not all proteins are created equal. There are several protein types to choose from, each with their own unique aspects and potential benefits."

Whey concentrate is the most popular form of protein powder, because it's easy to find, mixes well, and gets absorbed quickly. It is usually between 70-80 percent protein, with the rest of the mass coming from carbs, fats, and moisture. It can also be used before or after exercise and as a protein-rich snack between meals.

Whey isolate has little to no fats and carbs, and is usually around 85 percent protein. It is absorbed very quickly, making it a good choice immediately before and after physical exercise. It is also usually among the lowest-calorie protein powders

Whey hydrolysate is protein that has been partially broken down before you drink it. Your body is able to quickly absorb it to immediately start rebuilding damaged muscle tissue.

Casein is a popular choice for a nighttime protein drink because your body absorbs it more slowly than whey. Whereas whey gets absorbed in as little as 20 minutes, casein takes more like 3-4 hours.

Milk protein isolate contains both whey and casein proteins, since both of those are present in milk. It is a common ingredient in ready-to-drink (RTD) proteins, and can help provide your muscles with amino acids both in the short term, and for several hours after you drink it.

Egg protein concentrate is a popular ingredient in protein blends, because it takes longer than whey protein to digest, but not as long as casein. Many athletes also get their egg protein from liquid egg whites, or of course, eggs! A medium-sized egg contains around 7 grams of protein.

If you're looking for a vegan or vegetarian protein, there are more options than ever. Some of the most popular plant proteins include:

Soy protein is unique because it is one of the only complete vegetarian proteins. Soy products are rich in the three branched-chain amino acids, which also help your body recover and rebuild after physical activity. It is also high in glutamine, which helps your body recover after exercise, and arginine, which helps dilate blood vessels to get nutrients to your muscles more quickly.

Pea protein is an increasingly popular option, usually made from yellow split peas. It does not have the same amount of the three branched-chain amino acids as whey, but has a more complete amino acid profile than many other vegetarian options. It is a common ingredient in vegetarian protein blends, but also popular among people with dairy allergies.

Brown rice protein isn't a complete protein, but that doesn't necessarily mean it's not worth taking—as long as you take enough. A prominent study found that resistance-trained men who ingested 48 grams of rice protein on training days experienced similar muscle gains to men taking the same amount of whey. A second study in professional mixed martial artists also found muscle benefit similar to whey with the daily ingestion of brown rice protein isolate.[7]

Hemp protein is an increasingly popular choice because of its high digestibility. Hemp is also higher in fiber than many other proteins, which can help reduce hunger sensations, and contains omega-3 fatty acids.

Mixed-plant proteins combine different incomplete plant proteins to form complete proteins, while also capitalizing on the high amount of nutrients in many plant-based proteins. Many high-quality plant protein powders include the other plant-based proteins listed here, as well as more exotic plant proteins such as buckwheat, amaranth, and all manner of vegetables.