SUPPLEMENTATION

Kreider, R. B., Kalman, D. S., Antonio, J., Ziegenfuss, T. N., Wildman, R., Collins, R., Candow, D. G., Kleiner, S. M., Almada, A. L., Lopez, H. L. (2017). Journal of the International Society of Sports Nutrition, 14(1), 18.

The field's authoritative consensus statement: no compelling evidence that short- or long-term creatine monohydrate use (up to 30g/day for 5 years) has detrimental effects in healthy individuals, and consistent evidence it improves exercise performance and training adaptations. The baseline safety and efficacy reference for everything else in this category.

Burke, R., Piñero, A., Coleman, M., Mohan, A., Sapuppo, M., Augustin, F., Aragon, A. A., Candow, D. G., Forbes, S. C., Swinton, P., Schoenfeld, B. J. (2023). Nutrients, 15(9), 2116.

Meta-analysis of creatine combined with resistance training on directly-measured (imaging) regional muscle hypertrophy, finding a real, meaningful additive effect on muscle growth beyond resistance training alone.

Desai, I., Pandit, A., Smith-Ryan, A. E., Simar, D., Candow, D. G., Kaakoush, N. O., Hagstrom, A. D. (2025). Nutrients, 17(6), 1081.

Directly compared creatine's effect on lean body mass with versus without resistance training. Creatine supplementation alone, with no training stimulus, was largely ineffective for building lean mass, the benefit shows up specifically when it's paired with resistance training, not from the supplement in isolation.

Kazeminasab, F., Kerchi, A. B., Sharafifard, F., Zarreh, M., Forbes, S. C., Camera, D. M., et al. (2025). Nutrients, 17(17), 2748.

Meta-analysis of 69 studies (1,937 participants) found creatine plus resistance training produced small but significant strength gains in bench/chest press and squat, and improved vertical jump and Wingate peak power, but showed no significant benefit for handgrip or leg press specifically. The effect was also stronger in younger adults than older adults, and stronger in men than women for several outcomes (leg press, squat, vertical jump). Creatine's benefit isn't uniform across every exercise or population, it shows up most clearly in compound barbell lifts, younger lifters, and men.

Xiao, Y., Ding, L., Xu, Z., Liu, J., Guo, L., Barnes, M. J., Cao, Y., Girard, O. (2025). Frontiers in Nutrition, 12, 1686283.

Meta-analysis of 12 studies (230 participants) found a single dose of caffeine before training meaningfully improved bar velocity (SMD 0.42) and power output (SMD 0.21) during resistance exercise, holding up regardless of load. The effect wasn't uniform: men saw roughly double the velocity benefit of women (SMD 0.56 vs 0.22), and people who don't normally drink much caffeine (under 3mg/kg/day habitually) responded far more (SMD 0.87) than habitual high consumers (SMD 0.21). Caffeine works, but who benefits most depends a lot on sex and how caffeinated your normal diet already is.

Liang, L., Chen, M., Qi, B. (2026). Frontiers in Physiology, 17, 1892370.

Most caffeine-and-lifting research is done on men or mixed groups, so this review specifically pooled 24 studies (107 effect sizes) in women. The honest result: caffeine's benefit for maximal strength in women was real but small (g=0.17) and rated low-certainty, muscular endurance showed a larger effect (g=0.54) but with poor reproducibility across protocols, and movement speed data was too thin to draw a real conclusion from (very low certainty, only 3 study clusters). The authors explicitly said the evidence doesn't yet support firm dosage or timing recommendations for women specifically. A useful, honest counterweight to the broader, more male-skewed caffeine literature above [see Xiao et al. 2025], not a case against caffeine for women, just a real gap in how confident anyone should be about it.