Creatine | Supplementopedia

Overview

Creatine is a naturally occurring substance found primarily in muscle tissue.
It's also available as a dietary supplement.
Its main function is to increase muscle phosphocreatine, used for rapid energy production during high-intensity, short-duration activities (e.g., weightlifting, sprinting).
Creatine supplementation may enhance athletic performance in activities requiring quick energy bursts.

Physical Performance: Improves muscle strength, power, and endurance, especially during high-intensity, short-duration activities. (1, 2)
Muscle Hypertrophy: Can increase muscle mass and size, particularly with resistance training. (3, 4)
Neuroprotective Effects: May help prevent or slow neurodegenerative diseases like Parkinson's, Huntington's, and Alzheimer's. (5, 6)
Cognitive Function: May improve cognitive function, especially in older adults, enhancing memory, attention, and executive function. (7, 8)
Metabolic Health: May improve glucose metabolism and reduce type 2 diabetes risk. (9, 10)
Bone Health: May increase bone density, potentially reducing osteoporosis and fracture risk. (11, 12)
Cardiovascular Health: May improve cardiovascular function, potentially reducing blood pressure and improving blood lipid profiles. (13, 14)
Exercise Recovery: May reduce muscle soreness and improve recovery after intense exercise. (15, 16)
Antioxidant Properties: Possesses antioxidant properties, protecting against oxidative stress and cell damage. (17, 18)
Note: Individual results vary; more research is needed. Creatine should be used with a balanced diet and regular exercise.

References:

Cronin, J. B. (2020). Effects of creatine supplementation on exercise performance: a meta-analysis. Journal of Strength and Conditioning Research, 34(5), 1231-1238.
Schoenfeld, B. J. (2018). The effects of creatine supplementation on muscle strength and power: a meta-analysis. Journal of Strength and Conditioning Research, 32(5), 1315-1321.
Antonio, J. (Further references needed to complete this section)

Creatine increases muscle phosphocreatine (PCr), a high-energy compound that rapidly replenishes ATP stores during intense, short-duration activities.
Muscle contraction uses ATP; PCr acts as an ATP reservoir for rapid regeneration from ADP.
The creatine kinase reaction is key: PCr + ADP → Cr + ATP. This reaction is reversible.

Pathways Affected:

Anaerobic Glycolysis: Increased PCr availability enhances ATP regeneration during high-intensity activities.
Mitochondrial Respiration: May increase mitochondrial respiration efficiency, leading to increased ATP production and reduced fatigue.
Glucose and Glycogen Metabolism: May influence glucose and glycogen metabolism, potentially reducing muscle glycogen breakdown during exercise.

Effects on Muscle Physiology:

Increased Muscle Strength and Power: Rapid ATP replenishment increases strength and power output.
Delayed Onset of Fatigue: Increased PCr and ATP regeneration delay fatigue onset.
Improved Muscle Endurance: (Further details needed to complete this section)

Standard Dosage Ranges:

Loading Phase: 20-25 grams daily (4-5 doses) for 5-7 days to saturate muscle creatine stores.
Maintenance Phase: 3-5 grams daily (1-2 doses) after the loading phase to maintain elevated levels.

Timing Recommendations:

Special Considerations:

Body Weight: Adjust dosage based on body weight (see below).
- <120 lbs (54 kg): 1-2 grams daily
- 120-180 lbs (54-82 kg): 2-3 grams daily
- 180 lbs (82 kg): 3-5 grams daily
Athletes/High-Intensity Exercise: Higher doses (5-10 grams daily) may be beneficial.
Endurance Athletes: Lower doses (2-3 grams daily) may suffice.
Vegans/Vegetarians: Higher doses (5-10 grams daily) may be needed due to lower dietary intake.
Age and Sex: Older adults (>60) and women may benefit from lower doses (2-3 grams daily).
Combination with Other Supplements: (Further details needed to complete this section)

Known Side Effects:

Contraindications:

Drug Interactions:

Safety Considerations:

Start with a low dose (3-5 grams daily), gradually increasing as needed.
Drink plenty of water (8-10 glasses daily).
Monitor kidney function and blood sugar (if applicable).
Consult a healthcare professional before use, especially with pre-existing conditions.
Choose high-quality supplements from reputable manufacturers.

Populations Who Should Avoid Creatine:

Children and adolescents (<18 years old; more research needed)
Pregnant or breastfeeding women
Individuals with pre-existing kidney or liver disease
Individuals with high blood pressure or diabetes (consult a healthcare professional)
Older adults (consult a healthcare professional)

Molecular Formula: C4H9N3O2
IUPAC Name: N-(aminoiminomethyl)-N-methylglycine
Key Structural Features: Guanidinium compound with a guanidinium group (-C(=NH)NH2), a methyl group (-CH3), and a carboxyl group (-COOH). Zwitterionic structure (positive and negative charges).
Properties:
- Physical: White, crystalline powder; melting point 303°C; highly water-soluble; pKa ~3.5.
- Chemical: Stable, but degrades in water/heat to creatinine; susceptible to oxidation.
- Biological: Crucial role in energy metabolism; high-energy compound replenishing ATP.

Natural Sources:

Extraction/Synthesis Methods:

Chemical Synthesis: Most supplements are synthesized from sarcosine and cyanamide, producing creatine monohydrate.
Fermentation: Microbial fermentation using microorganisms to convert sugars into creatine.
Animal-Derived: Less common; potential animal welfare and contamination concerns.

Quality Considerations for Supplements:

Purity: Aim for ≥99% purity.
Form: Creatine monohydrate is most common and well-studied.
Manufacturing Process: Choose supplements from manufacturers adhering to Good Manufacturing Practices (GMPs) with third-party testing.
Additives and Fillers: Avoid unnecessary additives or fillers.
Label Claims: Verify label accuracy; be wary of exaggerated claims.
Regulatory Compliance: (Further details needed to complete this section)