Protein powder (whey/casein/plant)

It is not 'magic': it is a practical way to top up your protein.

• Tier A — Solid evidence — it works for most people
• Nutrition

What it is for

A convenient tool for hitting your daily protein target.

How it works

It provides essential amino acids, especially leucine, which activates mTORC1 and muscle protein synthesis. Whey digests quickly; casein slowly.

Dosing

Whatever you need to reach 1.6–2.2 g/kg/day. 20–40 g per serving covers the leucine threshold.

When to take it

Spread your protein across 3–5 servings. Whey works well post-workout or in the morning; casein before bed.

Safety

Safe in healthy people. It does not 'damage your kidneys' with normal renal function.

Side effects

Digestive discomfort for the lactose intolerant (use isolate or a plant protein).

Interactions

None relevant.

Contraindications

Milk protein allergy; advanced kidney disease (seek medical advice).

Who it has been studied in

Useful for vegans (pea/rice/soy), older adults (a greater leucine requirement) and anyone who cannot hit their protein through food.

Frequently asked