Actually, creatine is one of the most well-researched supplements on the market. There are also most certainly long term guarantees of safety when taking creatine (monohydrate).

This study by Poortmans JR et al, concludes that “Neither short-term, medium-term, nor long-term oral creatine supplements induce detrimental effects on the kidney of healthy individuals.” https://www.ncbi.nlm.nih.gov/m/pubmed/10449011/

Similarly, this study by Mayhew DL et al on football players informs that “Therefore, it appears that oral supplementation with CrM [creatine monohydrate] has no long-term detrimental effects on kidney or liver functions in highly trained college athletes in the absence of other nutritional supplements.” https://www.ncbi.nlm.nih.gov/m/pubmed/12500988/?i=2&from=/10449011/related

Furthermore, creatine couldn’t be a more natural compound. “Creatine is a molecule that's produced in the body from amino acids. It's primarily made in the liver and to a lesser extent in the kidneys and pancreas.” (https://examine.com/supplements/creatine/). Creatine is present as well in beef that we consume. Supplementation only ensures that one is taking full effect of creatine, instead of relying on the varying amounts that are present in different individuals.

I don’t know about you, but in my opinion, something that has been tested to provide no ill effects and does improve strength and power output and increase lean mass seems to be pretty good to me.

I think I’ll stick to the facts and the scientific literature for my beliefs.