What Is Creatine and How Does It Work?
Creatine is a naturally occurring compound synthesised from arginine, glycine, and methionine — primarily in the liver and kidneys. It is stored as phosphocreatine in skeletal muscle, where it serves as a rapid ATP buffer during high-intensity contractions.
The mechanism: During maximal effort (sprints, heavy lifts), ATP depletes faster than aerobic metabolism can replenish it. Phosphocreatine donates a phosphate group to ADP → ATP, extending the duration of maximal output before fatigue.
The result: more reps completed at a given weight, higher peak power output, and faster recovery between sets.
Forms of Creatine Compared
| Form | Efficacy vs Monohydrate | Cost | Evidence Base |
|---|---|---|---|
| Creatine Monohydrate | ✅ Reference standard | $ Low | 500+ RCTs |
| Creatine HCl | ≈ Equivalent (claimed higher absorption unproven) | $$$ High | Under 10 RCTs |
| Buffered Creatine (Kre-Alkalyn) | ≈ Equivalent | $$$ High | 3 RCTs |
| Creatine Ethyl Ester | ❌ Inferior (converts to creatinine faster) | $$ Medium | 5 RCTs |
| Micronised Monohydrate | ≈ Equivalent (better mixability only) | $$ Medium | Monohydrate data applies |
Verdict: No creatine form outperforms monohydrate in head-to-head trials. Alternative forms exist solely as marketing differentiation.
Dosing Protocol
Standard (No Load)
- Dose: 3–5g per day
- Timing: Anytime (consistency > timing)
- Saturation: Full muscle saturation in ~28 days
Loading Protocol (Optional)
- Phase 1: 20g/day split into 4×5g doses for 5–7 days
- Phase 2: 3–5g/day maintenance
- Benefit: Reach saturation ~30% faster
- Drawback: Increased GI disturbance in some individuals
Does Timing Matter?
A 2013 study by Antonio & Ciccone found a statistically significant but small advantage for post-workout creatine consumption. The practical magnitude is negligible — consistency of daily intake matters far more than window timing.
Performance Outcomes: What the Evidence Shows
| Outcome | Effect Size | Notes |
|---|---|---|
| Strength (1RM) | +5–8% | Across multiple muscle groups in RCTs |
| Power output | +10–15% | Peak Watts in sprint protocols |
| Lean mass (8 weeks) | +1–2 kg | Includes water retention in muscle |
| Cognitive performance | Small-moderate | Most pronounced in sleep-deprived subjects |
| Endurance (>90 sec) | Minimal | Minimal benefit beyond PCr-dependent efforts |
Who Benefits Most from Creatine?
Creatine response is not universal. "Non-responders" (those who experience minimal benefit) typically already have high resting muscle phosphocreatine from dietary creatine (red meat, fish) or genetic variation.
| Population | Expected Benefit | Notes |
|---|---|---|
| Strength athletes | ✅ High | Well-documented across power sports |
| Vegetarians/vegans | ✅ Very High | Lower dietary creatine = more room for saturation |
| Older adults (50+) | ✅ High | Protects against age-related muscle loss |
| Endurance athletes | ⚠️ Low-Moderate | Some benefit in high-intensity intervals |
| Non-responders | ❌ Minimal | Estimated 20–30% of users |
How Does Creatine Compare to Other Supplements for Strength?
Is creatine worth it compared to protein powder for muscle gain?
These serve different mechanisms. Protein provides substrate for muscle protein synthesis; creatine improves training output. Both are additive. If choosing one, prioritise meeting protein targets (1.6–2.2g/kg bodyweight) before adding creatine.
Is creatine effective for cognitive performance?
Emerging evidence suggests modest cognitive benefits, particularly under conditions of sleep deprivation or mental fatigue. A 2022 systematic review found improvements in memory and reaction time with creatine supplementation in healthy adults, though effect sizes were smaller than in athletic populations.