Creatine Supplementation

Creatine monohydrate supplementation (3–5 g/day) combined with resistance training increases upper-body strength by ~4.4 kg and lower-body strength by ~11.4 kg versus training alone, adds ~1.1 kg lean mass, and is safe long-term in healthy adults.

The Issue

Muscle cells store phosphocreatine (PCr) to rapidly regenerate ATP during high-intensity efforts lasting 5–30 seconds (e.g., heavy lifts, sprints). Typical muscle creatine levels saturate at ~120–140 mmol/kg dry muscle; dietary intake from meat and fish supplies only ~1–2 g/day for omnivores and near-zero for vegetarians/vegans, leaving most active people 20–40% below full saturation.

When PCr depletes, performance drops and training adaptations slow. Supplementation raises muscle creatine by 20–40%, directly extending high-intensity capacity and amplifying strength and hypertrophy gains from resistance training. It does not build muscle without training and does not meaningfully affect aerobic endurance.

Low dietary creatine (vegetarian/vegan diets), aging, and high-volume power training make the limitation worse. Without supplementation, many miss 5–15% greater strength/power gains and ~1 kg extra lean mass over 8–12 weeks of training.

Key Evidence

Wang et al. (2024) – Meta-analysis of creatine + resistance training on strength

• 23 randomized controlled trials, 509 adults under age 50 (447 male, 62 female).
• Follow-up: mostly 4–12 weeks.
• Main finding: Creatine + RT produced +4.43 kg upper-body strength and +11.35 kg lower-body strength vs. placebo + RT (both p < 0.001). Males showed clear gains; females showed smaller/trend-level effects. High-dose (>5 g/day) trended better for lower body.
• Link: https://www.mdpi.com/2072-6643/16/21/3665

Delpino et al. (2022) – Meta-analysis on lean body mass

• 35 studies, 1,192 participants (young, middle-aged, and older adults).
• Main finding: Creatine + resistance training increased lean body mass by 1.10 kg (95% CI 0.56–1.65) regardless of age; males gained ~1.46 kg, females ~0.5–0.6 kg (non-significant). No added benefit without resistance training.
• Link: https://www.sciencedirect.com/science/article/abs/pii/S0899900722002040

Kreider et al. (2025) – Comprehensive safety review

• 680 clinical trials, >12,800 participants, doses up to 30 g/day, durations up to 14 years (infants to elderly, healthy and clinical populations).

• Main finding: No clinically significant adverse events. Minor side effects (e.g., transient water retention) not different from placebo. Real-world adverse-event databases (28+ million reports) show creatine mentioned in ~0.0007% of cases despite billions of doses.
• Link: https://www.tandfonline.com/doi/full/10.1080/15502783.2025.2488937

Supporting studies

• Chilibeck et al. (2017) meta-analysis in older adults: +1.37 kg lean mass and significant upper- and lower-body strength gains.
• Multiple position stands (Kreider 2017 ISSN, etc.) confirm consistent ergogenic effects for high-intensity performance.

Note on popular claims: Media often overstates cognitive benefits or claims creatine is “essential.” Performance and hypertrophy effects are large and consistent; cognitive effects (memory, attention, processing speed) are smaller, more variable, and strongest in stressed, sleep-deprived, or older individuals. Kidney-damage fears stem from elevated serum creatinine (a harmless byproduct of creatine use), not actual GFR decline—confirmed in long-term studies including high-protein diets.

Who Is Most At Risk

• Vegetarians and vegans (lowest baseline muscle creatine; largest relative gains)
• Older adults (>50) at higher risk of sarcopenia and reduced training response
• Individuals doing resistance training or power/sprint sports 3+ sessions/week without supplementation
• Those with low red meat/fish intake (<2 servings/week)

Actionable Steps

Daily Dosing

• Take 3–5 g creatine monohydrate every day (cheapest, most researched form).
• Optional loading phase: 20 g/day (4 × 5 g) for 5–7 days to reach saturation faster—then drop to 3–5 g maintenance.
• No need to cycle on/off.

Timing and Synergy

• Consume with a meal or shake containing protein and/or carbohydrates to improve uptake (optional but helpful).
• Timing does not matter—consistency does. Post-workout is convenient but not superior.

Practical Habits

• Use a simple powder mixed in water, juice, or protein shake.
• Expect 1–2 kg scale-weight gain in first 1–2 weeks (intracellular water)—this is normal and beneficial.
• Drink normal-to-high water intake; no special hydration protocol required.

Monitoring

• Track strength progress in key lifts (bench, squat, deadlift) every 4–6 weeks—gains should accelerate.
• If you have pre-existing kidney disease, consult a doctor before starting (healthy kidneys handle it fine).

Quick Self-Check

• Do you eat red meat or fish at least 2–3 times per week?
• Are you currently doing resistance training or high-intensity power work 3+ days/week?
• Are you vegetarian/vegan or over age 50?
• Have you noticed a plateau in strength gains despite progressive overload?

Decision rule: If you answer “yes” to training frequency and “no/low” to meat intake (or are older/vegan), start 5 g/day creatine monohydrate immediately. Reassess strength progress after 8 weeks.

Related Notes

• protein-intake
• resistance-training
• evidence-optimized-workday

Sources

• Wang Z, et al. (2024). Effects of Creatine Supplementation and Resistance Training on Muscle Strength Gains in Adults <50 Years of Age: A Systematic Review and Meta-Analysis. Nutrients. https://www.mdpi.com/2072-6643/16/21/3665
• Delpino FM, et al. (2022). Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass: a systematic review and meta-analysis. Nutrition. https://www.sciencedirect.com/science/article/abs/pii/S0899900722002040
• Kreider RB, et al. (2025). Safety of creatine supplementation: analysis of the scientific literature. Journal of the International Society of Sports Nutrition. https://www.tandfonline.com/doi/full/10.1080/15502783.2025.2488937
• Kreider RB, et al. (2017). International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. https://pmc.ncbi.nlm.nih.gov/articles/PMC5469049/
• Chilibeck PD, et al. (2017). Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis. Open Access J Sports Med. https://www.dovepress.com/effect-of-creatine-supplementation-during-resistance-training-on-lean--peer-reviewed-fulltext-article-OAJSM
• Additional supporting reviews: Wax et al. (2021), PMC8228369.