If you’ve ever stepped foot in a gym or followed fitness content online, you’ve definitely heard the hype around creatine. It’s like the OG of workout supplements—helping with strength, muscle growth, and even brain power. But there’s always been that one lingering worry: Can creatine mess with your kidneys?

Short answer? For most healthy people— it’s totally safe. But, like with anything, there’s some nuance.

What is creatine?
Your body actually makes creatine on its own. It’s made in liver, kidneys, and pancreas, and gets stored in your muscles. When you do quick, explosive stuff like sprinting or lifting weights, your muscles use creatine for fast energy. Supplements (usually creatine monohydrate) just bump up those reserves so you can go harder and recover quicker. That’s why athletes and gym bros love it.

What does the research say?
Let’s look at some key studies:

Kreider et al. (2017) did a massive review of creatine’s safety and found no evidence that creatine harms function in healthy individuals, even with long-term use (up to 5 years in some studies).

In a 2011 by Gualano et al., healthy adults took creatine for 21 months with no changes in kidney markers or function. They concluded it’s safe for long-term use in healthy people.

A 2004 (Poortmans & Francaux) also showed no negative kidney effects after 5 years of daily creatine in athletes.

If your kidneys start out healthy, creatine itself doesn’t seem to cause damage or disease.

But who shouldn’t go all in without thinking?
Let’s not pretend it’s magic dust for everyone.

Already have kidney issues? Creatine could be a bit of a red flag. Your kidneys filter creatinine (a byproduct of creatine), so if they’re already not at their best, adding extra strain isn’t ideal. Always talk to your doc before starting.

Overdoing it? The sweet spot is around 3–5 grams per day (after a loading phase if you’re doing one). Mega-dosing, stacking it with other random supplements, or not following instructions? That’s a no-go.

Not drinking enough water? Creatine pulls water into your muscles. If you’re not hydrating properly, it could put pressure on your kidneys—especially during sweaty workouts. Water is your best friend here.

Want to play it safe? Here’s your game plan:
Get a kidney function test before you start, especially if you’re over 40 or have health issues like diabetes or high BP.

Stick to the recommended dose—3 to 5 grams per day. That’s enough.
Hydrate like it’s your job, especially before and after workouts.
Notice anything weird—like swelling, peeing less, or feeling drained for no reason? Don’t ignore it.