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Creatine Monohydrate

Muscle-preservation insurance during GLP-1-driven weight loss.

What it is

The most-studied performance/muscle supplement on the market. Increases ATP availability for short-burst work; pulls water into muscle cells (mild bloat); modestly reduces muscle catabolism during deficits.

Why peptide users take it

GLP-1 weight loss is ~25% lean mass without intervention, that's not just fat. Creatine + resistance training is the most evidence-backed defense against muscle loss during a deficit. Especially important for older users on tirzepatide/retatrutide.

Pairs with these peptides

Tirzepatide
Long deficit cycles risk significant lean mass loss
Retatrutide
Larger weight loss = larger lean mass loss without intervention
Semaglutide
Same, slower trajectory
MK-677 (Ibutamoren)
Synergistic, both increase muscle hydration and protein synthesis

How it actually works

Creatine gets stored in muscle as phosphocreatine, a fast-access energy reserve that regenerates ATP for short, intense work (sets, sprints). Higher stores mean you produce more force and recover faster between sets, which preserves training quality during a deficit. Training quality is the actual driver of muscle preservation when calories are low.

Dose

Members only

When to take

Members only

Signs you actually need this

  • Performance plateaus or regression in the gym while losing weight
  • Strength drops noticeably between sets within a workout
  • Disproportionate lean mass loss on a DEXA or scale
  • Recovery between training days takes longer than usual

Signs it's working

  • 1–3 lb water-weight gain in week 1 (intramuscular, not fat)
  • Strength holds or increases despite the calorie deficit
  • More reps in the tank by week 2–3
  • Visible muscle fullness even while losing weight overall

Common mistakes

  • Skipping it during a cut because you 'don't want the bloat', that's intramuscular water and it's protective
  • Loading phases (20 g/day for 5 days), unnecessary and just causes GI distress; 5 g/day works fine
  • Buying expensive 'HCl' or 'buffered' versions, monohydrate is the best-studied and cheapest by 5x
  • Cycling on/off, intracellular stores fall back to baseline within weeks of stopping; just take it daily

Where to buy

Editorial picks. Brand selection follows the quality criteria (USP/NSF or third-party COA where possible). Affiliate links , see the disclosure at the bottom of /supplements.

Caveats

  • Causes 1–3 lb water-weight gain in week 1. Don't panic, that's intramuscular.
  • Stay extra hydrated; creatine pulls water into cells.

Turn this peptide into a plan that's yours

The info above is free. Membership makes it personal, the Coach answers questions about your exact stack, the Stack tracks it for you, and the Verified Sources shows you how to vet what you buy.

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Also worth knowing: if you're injecting peptides alongside this stack, the injection-supplies page covers syringes, pads, sharps, and vial storage in the same quality-first format. Browse supplies →
Educational reference only. Not medical advice. Talk to a doctor before starting any supplement, especially if you take prescription medications or have an underlying condition.
~8% more strength
Rawson & Volek meta-analysis of resistance-training RCTs vs placebo

What it is

A compound your body already makes and stores in muscle, where it regenerates ATP — the energy currency for short, explosive efforts. Supplementing tops the tank up ~20-40%. It is the most-replicated ergogenic supplement in existence.

How it works

Hard sets exhaust phosphocreatine in seconds. A fuller creatine pool lets you squeeze out an extra rep or two at the same weight, and those accumulated extra reps — not the powder itself — are what build additional muscle over months of training.

Which form to buy

Creatine monohydrateEveryone

The form behind essentially every positive trial. Cheap, stable, effective.

The answer. Everything else is marketing against it.

Micronized monohydrateMixability

Same molecule milled finer so it suspends better in water.

Fine — it is monohydrate.

Creatine HClMarketing

More soluble in water — but solubility is not efficacy, and the smaller-dose-works-the-same claim has never been demonstrated.

No shown advantage. Monohydrate.

Buffered (Kre-Alkalyn)Nothing in particular

The head-to-head trial found no advantage over monohydrate.

Skip.

Creatine ethyl esterAvoiding

Converts substantially to inert creatinine before reaching muscle — it tested WORSE than monohydrate.

Actively worse. Skip.

Ready-to-drink liquidsAvoiding

Creatine degrades in solution over time.

Buy powder.

What it actually does, graded

Strength & powerStrong

Hundreds of RCTs; meta-analyses land around ~8% extra strength gain vs placebo across programs.

Lean mass (with training)Strong

Consistent extra kilogram-plus over weeks-to-months of resistance work, part water, part real tissue from the extra training volume.

Older adults preserving muscleModerate

Works alongside resistance training; not a substitute for it.

CognitionLimited

Interesting signals under sleep deprivation and in vegetarians; healthy rested brains show little.

Hair lossNone shown

The fear traces to one small DHT study that was never replicated — and a 2025 randomized trial that actually measured hair density found no difference.

Pros and cons

Pros
  • The best evidence-to-cost ratio in the entire supplement world
  • Effect size large enough to notice in your own training log
  • Decades of safety data at 3-5 g/day
  • No cycling, no timing games — dose daily and lift
Cons
  • Scale jumps 1-2 kg early from intramuscular water — plan your feelings accordingly
  • A minority of people (higher-baseline responders) get little from it
  • GI grumbles if you dump a loading dose in at once
  • Does nothing for endurance-only training

What to expect

  • Week 1 (loading) or weeks 3-4 (3-5 g/day): muscle stores saturate; scale up 1-2 kg of water.
  • Weeks 2-6: an extra rep or two on hard sets — check the logbook, not the mirror.
  • Months: the accumulated volume shows up as measurable extra lean mass vs training without it.
  • Stop taking it: stores drain back to baseline over ~4 weeks; nothing crashes.

Interactions

CompatibleCaffeineThe old interference claim rests on thin, contested data; the practical consensus is they coexist fine.
CautionExisting kidney diseaseCreatine is safe for healthy kidneys across many trials, but established kidney disease changes the math — clinician territory.
MonitorCreatinine blood testsSupplementation nudges creatinine up, which can make routine kidney labs read worse than reality — tell whoever orders the test.

Is it for you?

Probably worth it if
  • You lift, sprint, or play anything explosive
  • You are vegetarian or vegan (lower baseline stores — bigger response)
  • You are an older adult doing resistance training
  • You want the one supplement with an effect you can verify yourself
Probably skip it if
  • You exclusively do long steady cardio
  • A kilogram of water weight genuinely matters for your sport class this month

Who should avoid it

  • People with diagnosed kidney disease, unless their clinician signs off

Research on this supplement

Papers about this supplement, not proof of the claims above. A title says what was studied, which is sometimes a negative result or a different question entirely.

  • Creatine and Cognition in Aging: A Systematic Review of Evidence in Older Adults
    Nutr Rev, 2026
  • Effect of creatine supplementation on kidney function: a systematic review and meta-analysis
    BMC Nephrol, 2025
  • The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis
    Front Nutr, 2024

Evidence base

A
622 research papers
Strong human evidence: either a phase 3 or 4 trial report alongside review-level evidence, or ten or more randomised controlled trial reports.

Where next

The full supplement shelfEvery staple, tiered by evidence — not by margin.→What people stack these aroundThe compound index, evidence-graded.→Ask Coach about Creatine MonohydrateAnswers with the research it stands on.→
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