Darren Candow says elevated kidney markers from creatine are false positives 99 out of 100 times

Creatine’s most frightening side effect may be a paperwork problem. On The Diary of a CEO, Darren Candow says that when creatine makes kidney numbers look weird on a blood test, “99 out of 100 times” it’s a false positive, not your kidneys waving a white flag.

That is the kind of claim supplement skeptics are trained to side-eye. Good. Side-eye it. The supplement world has earned every raised eyebrow, every “proprietary blend” joke, every dusty tub of neon powder hiding behind a blender bottle. But creatine is not some TikTok mushroom gummy with a mood board. It’s one of the rare gym-shelf staples with decades of research behind it, and Candow’s main job here is to drag it out of bro folklore and into the boring fluorescent light of lab work.

So I would say 99 out of 100 times uh that it’s a false positive. So, this is by far the biggest uh myth and there’s been randomized control trials for several years showing that creatine causes no detrimental effects to the kidneys.

The mechanism matters. Creatine breaks down into creatinine, and creatinine is one of the numbers used to estimate kidney function. So a person takes creatine, their creatinine may rise, the estimated filtration rate may look worse, and suddenly the supplement gets blamed like it snuck into the lab wearing a burglar mask. Candow’s advice is less glamorous than a viral supplement clip but much more useful, tell your doctor you take creatine before the blood work gets interpreted like a crime scene.

The kidney claim is strong, the number is showmanship

Candow is convincing on the broad point. In healthy adults, creatine has a serious safety record, and the creatinine confusion is a real clinical annoyance. The “99 out of 100” line, though, is a podcast number. It’s sticky, memorable, perfect for a thumbnail, and not something you should treat as a diagnostic law delivered from Mount Whey Protein.

That distinction is not nitpicking. If you already have kidney disease, abnormal labs, or a doctor telling you to stop freelancing your own medical chart, you don’t get to quote a podcast and walk backward out of the clinic. Candow says people with pre-existing medical conditions should speak to a doctor. He also says he can’t find a reason a healthy individual can’t take it, which is both reassuring and exactly the sort of sentence that needs the word healthy in blinking lights.

You know, I can’t find anybody that can’t or shouldn’t. The safety profile is exceptional. If they have pre-existing medical conditions, they definitely need to speak to their doctor.

The more interesting cultural point is that creatine has become a supplement for everyone while still being haunted by its old locker-room branding. Candow spends a lot of time swatting down the greatest hits, kidney damage, water retention, hair loss, cramps, and the idea that women should avoid it unless they want to wake up looking like a defensive end. His answer on women is blunt, he says the “only for men” myth is “100% false,” with evidence for strength, endurance, performance, lean mass, and even bone-health work from his lab.

The boring version wins

The funniest twist is that the fancy stuff loses. Not because it’s evil, but because it’s unnecessary. Candow’s preferred creatine is not a futuristic gummy, not a hyper-absorbed hydrochloride with packaging that looks like a Marvel villain’s pre-workout. It’s creatine monohydrate, the plain white T-shirt of sports nutrition.

All the evidence that you ever hear about the safety and efficacy of creatine is based on the old boring from 1832 creatine monohydrate.

His buyer’s guide is almost aggressively unsexy, monohydrate, Creapure if you can find it, and third-party testing such as NSF so you’re not accidentally sprinkling lead into your morning smoothie. This is where the episode is at its best, not promising transformation, but shrinking the decision. Don’t load unless you want to saturate faster. Five grams a day is a basic muscle dose. Older adults may need more. Splitting the dose can help if one big scoop makes you feel strange.

I put five grams in my water bottle during my workout. Mhm. And so now I’m consuming a little bit of creatine as I do my weight liifting or cardio and then I’ll consume a little bit in the morning as well. So I take about 10 grams a day at minimum on on a daily basis.

The claim to take home is not that creatine is magic. Candow is actually more restrained than the title makes him sound. He says creatine’s muscle-mass gains are real but modest, with stronger evidence for performance, training volume, recovery, and function. Less superhero serum, more reliable tool. If he’s right about the kidney scare, a lot of people have been avoiding one of the few supplements that doesn’t require a TED Talk, a coupon code, and a small act of faith.