Amino Acid
Protein
Also known as: whey protein, plant protein, barley protein, rice protein
Protein is a macronutrient composed of amino acids essential for building and repairing muscle tissue, supporting immune function, and maintaining overall body composition. It is obtained through diet or supplementation and is critical for athletes, active individuals, and general health maintenance.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Daily target & upper limit
50 g / dayProtein has an established daily reference intake. See best forms, label synonyms, upper-limit warnings, and top-scoring supplements:
Protein dosage reference →Primary uses
- Muscle building and recovery
- Post-workout recovery
- Muscle maintenance
- Satiety and weight management
- General nutritional support
How it works
- Provides amino acids for muscle protein synthesis
- Stimulates mTOR pathway for anabolic signaling
- Supports enzyme and hormone production
- Enhances satiety through metabolic effects
Dosage
- Typical range
- 20-40 g per serving, 1-3 servings daily
- Timing
- Post-workout timing is most effective; can be consumed throughout the day
- With food
- Can be taken with or without food; post-workout absorption may be enhanced with carbohydrates
- Duration
- Can be used long-term as part of regular supplementation
- Special populations
- Requirements increase with age (65+ may need 1.2-1.6 g/kg body weight); individualize based on activity level and training goals
Forms
- whey protein concentrate· 70/100
- whey protein isolate· 70/100
- plant-based blends· 70/100
- barley protein· 70/100
- rice protein· 70/100
Safety
Common side effects
- Bloating or gas (particularly with plant-based proteins)
- Digestive discomfort in sensitive individuals
- Occasional constipation
Contraindications
- Milk allergies (for whey/casein sources)
- Severe kidney disease (consult healthcare provider)
- Phenylketonuria (PKU) if containing phenylalanine
Products containing Protein
Top-scoring supplements in our catalog that list Protein on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Extensive RCT evidence demonstrates protein supplementation significantly supports muscle growth and recovery, particularly when combined with resistance training. Well-established macronutrient with decades of research.
Grade A: Multiple well-designed human trials support the main claims.
Cited research for Protein
Clinical studies referenced across Formulate guides that mention protein. Each links to the full study page with PubMed source + the guides that cite it.
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.