Creatine Works: On Muscle, Brain, and Sleep

January 30, 2026

Creatine is the rare supplement I'll call "boringly real."

A 2025 pooled analysis of 61 trials found that creatine meaningfully increases fat-free mass. The average effect was about +1.39 kg, and when you split groups it's roughly +1.82 kg in trained lifters vs +1.23 kg in previously untrained. That difference was not statistically significant, so the headline is simply: creatine reliably pushes lean mass up. (PMC)

My take on the "it's just water" complaint: yes, some of that early gain is intracellular water. That is not a consolation prize. It makes muscle look fuller, and it is part of the mechanism that supports performance and training volume. If it helps you do more quality work, it is doing its job.

The more interesting update: brain and sleep

A randomized, double-blind crossover trial in physically active men used a classic loading week (4 × 5 g/day for 7 days) and found:

• better subjective sleep quality
• better post-exercise cognitive performance (a focused scanning/processing task)
• no change in objective sleep metrics like latency, total sleep time, or efficiency
• less soreness, but no dramatic changes in objective recovery markers (PubMed)

And separately, a Scientific Reports study showed a single high dose of creatine during sleep deprivation improved cognitive performance and brain energy markers, with peak effect a few hours after ingestion. (Nature)

Practical bottom line

If you lift, 3–5 g/day creatine monohydrate is a high-upside, low-cost bet.

Loading is optional. It just gets you there faster.

It's also one of the most studied supplements for safety and efficacy in sport nutrition. (PubMed)

If you respond, you'll notice it. If you don't, you're out the price of a coffee per week.