What are the recommended dosing and precautions for using creatine (creatine monohydrate) supplements?

Creatine Monohydrate Supplementation: Dosing and Precautions

The recommended dosing protocol for creatine monohydrate supplementation is a loading phase of 20g/day (divided into four equal doses) for 5-7 days, followed by a maintenance phase of 3-5g/day, with careful monitoring in individuals with kidney disease or risk factors for renal dysfunction. 1, 2

Recommended Dosing Protocols

Standard Protocol

• Loading phase:

  • 20g/day divided into 4 equal doses (5g four times daily) for 5-7 days 1, 2
  • Alternative calculation: ~0.3g/kg body weight/day 2

• Maintenance phase:

  • 3-5g/day (single dose) 1, 2
  • Alternative calculation: ~0.03g/kg body weight/day 2

Alternative Protocol (No Loading)

• Lower dose approach of 2-5g/day for 28 days can be effective without the associated water weight gain 1
• Loading phase is not strictly necessary but accelerates muscle creatine saturation 2

Administration Considerations

• Concurrent consumption with a mixed protein/carbohydrate source (~50g of protein and carbohydrate) may enhance muscle creatine uptake via insulin stimulation 1
• Creatine monohydrate is the most studied and effective form; other forms such as creatine ethyl ester have not shown added benefits 2

Precautions and Contraindications

Renal Function Concerns

• Individuals with pre-existing kidney disease (eGFR <60 mL/min/1.73m²) should generally avoid creatine supplementation 3
• Creatine supplementation may add unnecessary nitrogenous load to compromised kidneys in chronic kidney disease patients 3
• For individuals with renal impairment, the following precautions should be observed:
  • Creatinine clearance <10 mL/min: Avoid supplementation 3
  • Creatinine clearance 10-50 mL/min: Use with caution and reduced dosing if necessary 4

Special Populations

• Individuals with diabetes, hypertension, or reduced glomerular filtration rate should exercise caution due to potential risk for renal dysfunction 4
• Young, healthy individuals without risk factors can typically use creatine with proper monitoring 3

Potential Side Effects

• Water retention: Transient water retention is the most common side effect, particularly during the loading phase 2
• Gastrointestinal issues: Some users report digestive discomfort, diarrhea 5
• Other reported effects: Muscle cramping, dizziness (though clinical evidence for these is limited) 5

Monitoring Recommendations

• Consider baseline assessment of kidney function before starting supplementation in individuals with risk factors 4
• Monitor for weight gain (typically 1-2kg) during initial supplementation period due to water retention 2
• Long-term supplementation (up to 30g/day for 5 years) has been shown to be safe in healthy individuals 6

Evidence Quality and Safety Profile

• Creatine is one of the most extensively studied sports supplements with over 500 peer-reviewed publications 7
• Research consistently shows that creatine is relatively well-tolerated at recommended dosages (3-5g/day) 7, 6
• Despite concerns, studies have not demonstrated significant adverse effects on liver or kidney function in healthy individuals 4

Creatine supplementation is most effective for high-intensity, short-duration activities and has been shown to improve muscle mass, performance, and recovery when used appropriately 6. However, it's important to use high-quality products from reputable manufacturers, as supplements are not regulated with the same standards as pharmaceuticals 5.