I use creatine since about 2 years, it's one of the most researched supplements.
I don't cycle I just do 5g a day, did a blood test last year all good.
I notice the effect being more power during training and less muscle fatigue.

Here's the only video you need on creatine
www.youtube.com/watch?v=IR5jW…

Here's the product I buy, just make sure it's creatine monohydrate (no other stuff aded) and you are good to go

www.amazon.de/Creatin-Monohyd…