Protein powder: who needs it, how much, and which kind

What is protein powder?

Protein is the body's basic building material for muscle, skin, hair, nails and immune cells. The amino acids in protein (the small pieces protein is made of) are also used to heal wounds and to make the hormone that helps you sleep (melatonin) and the chemicals that regulate mood.

Protein powder is simply protein made easy to take as a powder or drink. The most common types are whey protein, made from milk, and plant proteins from soy or peas.

Signs of low protein: who needs it

The more of these that apply to you, the more likely you're low on protein.

• □ Your nails break easily, and your hair is dry or falling out a lot
• □ The skin on your fingertips often peels
• □ You eat poorly or are dieting, and you often feel puffy or swollen
• □ You're losing muscle, feel tired, and fall easily
• □ You catch colds easily and cuts are slow to heal
• □ You're often hungry and gain weight easily

These groups in particular have a hard time getting enough from food alone:

• Adults over 50: After age 30, you lose 3–8% of your muscle every 10 years. As you age, less of the protein you eat goes to muscle, so you need more. One survey found that about 2 in 3 people aged 65 and older don't get enough protein.
• People who eat only two meals a day: Most fall short.
• People who are dieting: When you eat less, you lose muscle along with fat.
• Older adults who have trouble chewing or digesting: It's hard for them to eat enough meat.
• Women in menopause: Losing muscle raises the risk of falls and broken bones.

On Wegovy or Mounjaro? Start with protein

GLP-1 appetite-suppressing shots (Wegovy, Mounjaro and others) make you eat much less. When that happens, you lose muscle along with fat.

In one large study, people who lost about 20% of their body weight also lost about 11% of their lean mass (body weight minus fat), which includes muscle.

That's why, if you're on one of these shots, strength training plus extra protein is considered the top priority. Many people also add creatine to help prevent muscle loss.

How much protein do you need per day?

Bottom line: about 1 g per kg of body weight (about 0.45 g per lb). More if you're older or active.

Of this, use powder only for the gap — usually about half of what you need, or 20–30 g. A product with at least 10–15 g per serving, taken 1–2 times a day, will get you there.

• Don't take too much at once. A large amount at one time puts strain on your liver, kidneys and stomach. Older adults in particular find it hard to take 30–40 g at once.
• Be careful above 1.5 g per kg. Some experts suggest up to 1.5–2 g while on weight-loss medication, but some data show that more than 1.5 g per kg can strain the kidneys.
• Extreme amounts are dangerous. Getting more than 35% of your daily calories (about 200 g) from protein over a long time can cause "protein poisoning." Ammonia builds up in the blood, the liver and kidneys are damaged, and you get diarrhea.

When to take protein powder: before or after a workout?

Bottom line: how much you get in a day matters far more than when you take it.

The idea that you have to drink protein within 30 minutes after a workout to build muscle used to be popular, but it's been disproven. An analysis that pooled 23 studies found that total amount mattered more than timing, and other research found no difference between taking it before or after exercise.

1. If you work out, take it within 2 hours afterward so you don't forget.
2. If you don't work out, the morning is a good time. You stay full longer and your blood sugar rises more slowly.
3. Split it into 2 servings a day. 3–4 is ideal, but realistically 2 (morning and evening) is enough.
4. If it upsets your stomach, take it after a meal. You can take it on an empty stomach or as a meal replacement, but after a meal is easier if your stomach is sensitive.
5. Take it at a different time from amino acid supplements like collagen or arginine. They compete for absorption.

Types of protein powder: WPC vs WPI vs WPH vs plant

If you're new, whey protein isolate (WPI) is the safest pick. If dairy doesn't agree with you, go plant-based. The type makes almost no difference in how well it builds muscle.

Experts disagree on whether plant or whey protein is easier on the liver and kidneys. Some say high-purity whey is actually less of a burden; others say plant protein is better because it avoids lactose and allergy issues. To keep it simple: worried about your liver or kidneys? High-purity WPI. Dairy doesn't agree with you? Plant protein.

Powder vs. ready-to-drink: If your goal is protein, powder wins on both protein content and value. Drinks are convenient, but many are "complete nutrition" shakes that are more about vitamins and minerals than protein, so always check the grams of protein.

How to choose a protein powder: 4 things to check on the label

1. Grams of protein per scoop — For example, 27 g of protein in a 31 g scoop. The higher the protein compared with the scoop weight, the purer it is.
2. Sugar, carbs and sodium — Less is better. Even with "0 g sugar," many products are sweetened with artificial sweeteners like sucralose.
3. Contamination testing — Choose brands that publish results for bacteria, mold and heavy metal testing.
4. Certifications for plant protein — Look for USDA Organic, vegan and Non-GMO seals. Some "plant" products are actually mixed with whey.

Also keep in mind:

• Taste comes first. You'll drink it every day, so you need to like it to stick with it. Buy a small tub first.
• Avoid sports products that promise "bulking" or "testosterone boosting." Some have been found to contain illegal drugs and raised liver enzymes.
• If your kidneys aren't healthy, check whether minerals like calcium, magnesium or potassium have been added. On the other hand, if your kidneys are healthy, a product with calcium and magnesium can double as bone support.

Protein powder side effects: kidneys, liver, acne

If you're healthy and stick to the recommended amount, you're fine. Studies found that a moderate amount of protein powder didn't affect the liver. Problems come up when you take a lot, or when your liver or kidneys already aren't healthy.

• Kidney strain and stones: Extra protein breaks down into waste like urea and uric acid, and your blood tips toward acidic, which makes stones more likely.
• Dehydration: You urinate more. Drink more water than usual.
• Liver strain: Processing protein creates ammonia, which the liver filters out. In people with serious liver disease, this can lead to hepatic encephalopathy (confusion caused by ammonia buildup).
• Digestive upset: Concentrated protein can easily upset the stomach in older adults or people with gastritis or bowel conditions. Split your servings, take it after meals, or switch to WPH or plant protein.
• Acne: Whey protein is a well-known acne trigger. If your acne gets worse, switch to plant protein.

Talk to your doctor before taking it if any of these apply:

• You have poor kidney function, take kidney medication, or have heart failure
• You have reduced liver function or liver disease
• You often get kidney or urinary stones (if you take it, stick to a moderate amount)
• You have gout
• You have a stomach condition like gastritis or a stomach ulcer

For reference, calorie for calorie, protein is less likely to turn into body fat than carbs. That's why a protein shake is a better snack choice when you're dieting.

Combinations

Works well with: Creatine, Essential amino acids (EAA)

Space apart from: Collagen, L-Arginine

Frequently asked questions

Related concerns