Creatine is not bad for your heart — in fact, creatine cut mortality in a 2016 meta-analysis

The fear is backwards

People worry creatine strains the heart. That worry has it completely backwards.

Your heart runs on a molecule called phosphocreatine — the phosphorylated form of the creatine you take as a supplement. It's one of the main energy sources keeping your cardiac muscle contracting beat after beat. When phosphocreatine levels drop in the heart, that's when things go wrong (Del et al., 2022).

So the question isn't "does creatine stress the heart?" The real question is: what happens when the heart doesn't have enough of it?

Creatine deficiency in the heart — not excess — correlates with disease severity and contractile dysfunction.

— Del et al. (2022). Creatine deficiency and heart failure. Heart Fail Rev.

What phosphocreatine actually does in your heart

Your heart can't store much ATP — the molecule cells use directly for energy. Instead, it uses phosphocreatine as a fast energy buffer, shuttling stored energy between the mitochondria (where it's made) and the muscle fibres (where it's used).

This system is called the creatine kinase energy shuttle, and the heart relies on it more than almost any other organ in the body. In heart failure, phosphocreatine levels fall first — before ATP even drops (Del et al., 2022). The degree of that drop tracks directly with how severe the disease is and how poorly the heart contracts.

That's not a minor detail. That's the mechanism. Creatine depletion is a marker — and possibly a driver — of cardiac decline.

The meta-analysis that flips the narrative

In 2016, researchers pooled 41 controlled trials — 32 of them randomised — testing what happens when you give phosphocreatine directly to patients with coronary artery disease, chronic heart failure, or those undergoing cardiac surgery.

The results weren't subtle:

- All-cause mortality was 29% lower in the phosphocreatine group (3.5% vs 10.6%; OR: 0.71) (Landoni et al., 2016).
- Left ventricular ejection fraction — a key measure of how well the heart pumps — was 3.82 percentage points higher in treated patients (Landoni et al., 2016).
- Peak cardiac enzyme release (a marker of heart muscle damage) was 6.08 units lower in the phosphocreatine group (Landoni et al., 2016).

This is 3,400 patients across 22 trials showing lower mortality. That's not a small signal.

Creatine also protects against ischemia, arrhythmia, and fibrosis

The cardioprotective effects go further than heart failure. A 2024 review found that phosphocreatine is used clinically to treat ischemic heart disease (restricted blood flow to the heart), arrhythmias, myocardial fibrosis, myocarditis, and the damage caused by myocardial infarction — a heart attack (Wang et al., 2024).

The protection works through multiple pathways. Phosphocreatine reduces cell death (apoptosis) and lowers oxidative stress — the kind of cellular damage that builds up during and after a cardiac event. It also activates signalling pathways that help the heart recover after injury (Wang et al., 2024).

Again: this is not a mechanism of harm. It's the opposite.

Phosphocreatine is used clinically as a cardioprotective drug — for ischemic heart disease, arrhythmia, and myocarditis.

— Wang et al. (2024). Clinical applications of phosphocreatine and related mechanisms. Life Sci.

Where the fear comes from — and why it doesn't hold up

The concern about creatine and the heart usually comes from two places:

1. Creatinine levels on blood tests. Creatine breaks down into creatinine, which the kidneys filter out. When you're supplementing creatine, your creatinine rises slightly. Doctors sometimes flag this as a sign of kidney or cardiovascular stress. But in a healthy person, it's just the normal byproduct of higher creatine turnover — not damage.

2. Conflation with anabolic steroids. Creatine is not a steroid. Steroids genuinely do carry cardiac risks — left ventricular hypertrophy, reduced ejection fraction, arrhythmias. Creatine has none of those mechanisms. It's a compound your body makes naturally from the amino acids glycine and arginine.

The scoping review of 16 randomised trials on creatine supplementation for muscle growth (covering 2012–2021) found no cardiac safety concerns flagged across any of those studies (Wu et al., 2022). These weren't tiny trials — they covered healthy young adults, older adults, and clinical populations.

What this means for your training

If you're a healthy person lifting weights, creatine monohydrate is one of the most studied supplements on the market — and the cardiac evidence points in one direction: neutral to protective, never harmful.

The standard dose is 3–5 g per day. No loading phase required, though some people use 20 g/day for 5–7 days to saturate faster. Either way, long-term use at these doses shows no adverse cardiovascular signals in the literature.

If you have an existing heart condition, that's a conversation to have with your doctor. But the clinical research on phosphocreatine — the same molecule — is actually being used to treat heart conditions, not avoid them.

For training purposes, creatine helps you push harder on compound movements like barbell row and bench press — and that progressive overload is what actually drives muscle growth, as covered in progressive overload training.