You can mix creatine with pre-workout. Creatine does not react with any common ingredients found within pre-workout supplements. There was some speculation that loading creatine with chronic caffeine use could blunt the effects of creatine, however, this has been dismissed by many studies. Until further evidence is published, we can conclude that taking creatine and pre-workout together is fine. Taking creatine with a pre-workout unfortunately has no additional benefits. Creatine does not lead to any acute benefits in performance. It is not a stimulant and needs to be taken chronically. Some evidence suggests that taking creatine after exercise may be better for muscle growth, but not strength. However, the effect may not be practical enough to follow. Therefore, taking a separate pre-workout supplement daily is a better choice than choosing a pre-workout supplement with creatine. There are little to no side effects with taking creatine. When creatine is in a pre-workout, any side effects are usually not from the creatine, but from other ingredients like beta alanine, which causes itching and tingling of the skin.
Take creatine any time of the day, every day. There is no benefit to taking it before or after your workout, so simply take it whenever you remember/prefer. The typical dose is 5g per day, which is also the easiest to measure, as it is 1 teaspoon. However, you can get results with doses as low as 2 to 3g per day, especially if you eat red meat. It takes approximately 28 days to saturate the muscles thoroughly with creatine. There are no issues with mixing creatine with pre-workout. Just know that it won’t provide you with any additional benefit over taking creatine at any other time of the day.