Even as an informal conclusion I think it's important to know who you're up against and what their motivations are. Waving that away is how we get people like known, obvious charlatans like RFK Jr in any sort of position of power. I know this is nitpicking word choice but the informal conclusion is "Not likely, and not enough to matter for anything."
With most industries companies live and die by their reputation. Find a bulk provider with a positive reputation and the creatine you buy is almost certainly going to be safer than e.g. eating at Taco Bell. And with creatine in particular it's so dirt cheap that a lot of motivation for dodgy stuff goes away unlike e.g. with protein powders where amino acid spiking can save a company a bunch of money. And incidentally creatine is one of the substances dodgy companies use for amino acid spiking, just because it's so cheap!
That said it's obviously the right decision to drop it if you're not seeing any effects. The interesting thing about creatine is that people's bodies are very different in their natural levels of creatine, and if you're already at 'saturation' then more creatine isn't going to do anything. Same reason the typical benefits of creatine don't show much difference beyond 5g/day. That's enough to send the overwhelming majority of people towards 'saturation.'
There is a brand of creatine manufactured in the US (con-cret) and a brand manufactured in Germany (Creapure). Either of those companies should address the concern around adulterated powder.
> That's why I dropped creatine since I didn't notice any benefits when I tried it for a year.
Some percentage of people (~20%) are creatine non-responders [1]. It's pretty reasonable to try creatine and then drop it if you find no benefit. I personally find the gain very marginal.
You still haven't specified what negative side effects you're referring to. Nitrogen tends to be inert, so I'm questioning your claim that N2 causes some negative side effect, not your claim that creatine hinders this yet-unnamed side effect
What value is there to an informal conclusion when the topic is as important as intelligence? The downsides to creatine if taken without good scientific backing should not be disregarded, yet that’s exactly what many ordinary people are now doing because of “informal conclusions” like this.
Are there really downsides to creatine though? (Genuine question). All the advice I've seen makes it seem like it's basically just good for you even if it doesn't accomplish some specific thing. The only downside I've heard is maybe water retention?
That's not the point. Often in medicine, the downside of using one thing is that you're not using another thing that would be safer and more effective. When people chase results from unproven therapies, often it means they're avoiding doing something else that is known to produce a result - even if the result of the alternative is not as spectacular as the unproven therapy promises to be.
But speaking of creatine itself, while not inherently toxic, consuming large doses can cause serious indirect harms, such as triggering falsely elevated kidney markers on blood tests that lead doctors to misdiagnose organ failure, unnecessarily cancel crucial medical treatments, or order invasive biopsies. Furthermore, overloading the body with creatine while taking kidney-stressing medications (like heavy doses of ibuprofen) or having an undetected renal condition can cause actual acute kidney strain, while the massive shift of water into muscle cells can trigger severe dehydration, heat exhaustion, and electrolyte imbalances during intense heat or exercise if fluid intake falls behind.
But, I don't want to belabour the point about creatine. Rather, I want to focus on the negatives stemming from NOT doing other things that ARE proven to be safe and effective. People tend to think creatine will solve a lot of their problems (for instance, they may believe it will fix their feeling of being "low energy). But by avoiding things that might actually help their problem get better, they're persisting a poor state of health.
Taking creatine does not bar you from doing other things. Being "low energy" is too general a thing, and to approach you probably need to start eliminating factors anyway until you find the issue, by getting better sleep, doing blood tests etc. Taking creatine can be part of this.
Creatine supplementation not having significant effect in X domain in population level does not mean that it will not have effect on YOU if for example you are vegan and don't get enough creatine from diet. If you have low energy, probably you have something that may not show in a population level. Similarly you may be low in B12 and then B12 can help you, but it may not show effects in population level if most of the population is not low in B12 (and your study is not powered enough to catch nuances).
It is not like when you have to choose between two medicines and excluding one can be harmful even if the other is not harmful to take per se. You can supplement creatine and try whatever else at the same time.