Creatine monohydrate is, quietly, the most researched and best-evidenced supplement in sports nutrition. Hundreds of human trials over three decades back it up — and recently research has expanded beyond the gym into something more interesting: the brain.
What creatine is and how it works
Creatine is a compound your body makes naturally and stores mostly in muscle, where it helps regenerate ATP — your cells' rapid energy currency. Supplementing increases the phosphocreatine stored in muscle, letting you produce more energy during short, intense efforts. That means a bit more work per session, and it's that accumulated training stimulus that drives the long-term gains.1
The evidence: strength and muscle
This is where creatine's reputation is earned. A meta-analysis of 22 studies involving 721 older adults found creatine combined with resistance training produced significantly greater gains in lean tissue mass — a mean difference of about 1.37 kg — versus resistance training alone.2 Creatine doesn't build muscle on its own, but it reliably amplifies what training delivers. That effect held up across programs ranging from 12 weeks to a year, which is part of why the strength-and-muscle case for creatine is considered closed by most sports scientists, even where other claims about it remain open questions.
Do other forms of creatine — HCl, buffered, or "advanced" blends — beat monohydrate?
Walk down a supplement aisle and you'll find creatine hydrochloride (HCl), buffered creatine (sold as "Kre-Alkalyn"), creatine ethyl ester, and various patented blends, usually priced well above plain monohydrate and marketed on claims of better solubility or absorption. The solubility claim is real — HCl does dissolve in far less water than monohydrate. Whether that translates into a better result in your body is a separate question, and it's the one that actually matters.
An 8-week randomized controlled trial in resistance-trained adults put that question to a direct test. Participants were split into a creatine HCl group, two creatine monohydrate groups (one using a loading protocol, one without), and a placebo group, all training the same way. All three creatine groups improved leg-press and bench-press strength, skeletal muscle mass, and hormonal markers (including the testosterone-to-cortisol ratio) significantly more than placebo — but there was no meaningful difference between the HCl group and either monohydrate group on any of those measures.5
That result matters for your wallet as much as your training. Monohydrate is typically the cheapest form per effective gram, has by far the longest human safety record, and is the version used in essentially every strength, lean-mass, and cognition trial referenced in this guide. Paying more for a "better absorbed" form buys you faster dissolving in your shaker bottle — not, on the evidence so far, a better outcome in the gym.
The newer frontier: cognition
Because the brain is also energy-hungry and uses phosphocreatine, researchers have asked whether creatine supports cognition too. A 2024 systematic review and meta-analysis of 16 randomised controlled trials (492 participants) found significant positive effects on memory, attention and processing speed.3 Honest caveats: certainty was moderate for memory but low for the others, and effects may be clearest when the brain is under stress (sleep deprivation, older age). Promising, not settled.
How to take it: do you need to load?
Two equally valid options, per the International Society of Sports Nutrition position stand:1 a short loading phase that saturates muscle stores fast, or a flat daily dose that gets you to the same place more gradually. Most people skip loading — it's simpler, gentler on the stomach, and reaches the same destination.
| Protocol | Daily dose | Time to full saturation | Trade-offs |
|---|---|---|---|
| Loading | ~20–25 g (split into 4–5 doses) for 5–7 days, then 3–5 g/day | ~5–7 days | Faster onset; more GI upset reported at higher single doses |
| No loading | 3–5 g/day from day one | ~3–4 weeks | Simpler, gentler on the stomach; same end result |
Consistency matters more than either protocol: take it daily, with or without food, and the muscle saturation curve takes care of itself.
Safety: putting the myths to rest
- Kidneys: current research indicates creatine does not harm kidney function in healthy adults at recommended doses. It causes a small, transient rise in serum creatinine — normal metabolism, not kidney damage, with no meaningful change in filtration rate. The renal-toxicity concern traces back to isolated case reports, some with pre-existing kidney conditions.4
- "It's a steroid": it isn't. Creatine is a naturally occurring compound found in food (notably red meat and fish).
- Caution: those with pre-existing kidney conditions, and people who are pregnant, should consult a doctor first, as evidence in those groups is limited.
Creatine for women
Creatine is often assumed to be a "men's" supplement — it isn't. For lean mass and strength, the case for women looks much like the case for men. For bone specifically, though, the picture is more mixed than marketing usually admits, and it's worth being precise about what the best trial actually found.
The most rigorous test to date is a two-year, randomized, placebo-controlled trial in 200 postmenopausal women with low bone mass, published in The Journals of Gerontology: Series A. Over 24 months, women took either 3 g/day of creatine or a placebo alongside their normal activity. Bone mineral density at the lumbar spine, femoral neck, and total femur declined in both groups at a similar rate, with no statistically significant protective effect from creatine and no difference in falls or fractures between groups.6 Lean muscle mass increased over the study, but that improvement occurred regardless of whether participants were taking creatine or placebo.
That's a less exciting result than the headlines about "creatine for bone health" usually suggest, and we'd rather say so plainly than round it up. At this dose and duration, in this population, the best-designed trial found no measurable bone benefit — even though creatine's case for muscle and strength stands on much firmer ground. Some smaller studies pairing higher doses with heavier resistance training have reported modest positive signals on bone markers, so this isn't necessarily the final word, but it's the most reliable word we have right now. Separately, concerns about "bulking up" or water-weight gain from creatine are largely overstated: the fluid creatine draws into muscle is stored inside the muscle cells themselves, not as the puffy, under-skin retention people tend to picture.
This article is for informational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease. Speak with a healthcare provider before starting any new supplement, especially if you take medication or have an existing health condition.
The bottom line
If you train, creatine monohydrate is one of the few supplements with overwhelming evidence for strength and lean mass, a growing body of work pointing to cognitive benefits, and no good evidence that pricier alternative forms do anything monohydrate doesn't. It's cheap, safe for healthy adults, and simplest taken as 3–5 g daily — no loading required. Its case for protecting bone specifically is still open, and we'd rather tell you that than oversell it. That mix of strong evidence, honest limits, and low cost is why creatine was part of Proco's original range, at the core of Proco Creatine Monohydrate and the Performance Stack, before it was discontinued.
References
- International Society of Sports Nutrition position stand: creatine supplementation and exercise. JISSN. tandfonline.com
- Effect of creatine supplementation during resistance training on lean tissue mass and strength in older adults: a meta-analysis. OAJSM. tandfonline.com
- Effects of creatine supplementation on cognitive function in adults: systematic review and meta-analysis (2024). PMC. ncbi.nlm.nih.gov
- A short review of the most common safety concerns regarding creatine ingestion. PMC. ncbi.nlm.nih.gov
- Supplementing with which form of creatine (hydrochloride or monohydrate) alongside resistance training can have more impacts on anabolic/catabolic hormones, strength and body composition? (2024). Physiological Research, 73(5):739–748. biomed.cas.cz
- Sales LP, Pinto AJ, Rodrigues SF, et al. Creatine supplementation (3 g/d) and bone health in older women: a 2-year, randomized, placebo-controlled trial (2020). The Journals of Gerontology: Series A, 75(5):931–938. pubmed.ncbi.nlm.nih.gov
Related reading: Creatine and the Brain: What the Cognitive Research Actually Shows and Creatine Timing: Does Pre- vs Post-Workout Actually Matter?.
Creatine is no longer part of the Proco range. If focus and cognitive performance is what you're after, Cognitive Support is the closest fit in our current lineup. Shop Cognitive Support →