My creatinine serum is 0.50 mg and i am 37 f. am i ok ?

Should be OK,,,: Any creatinine above 1.5 is a problem that would need more renal studies. I don't know what your baseline creatinine is but this should be no trouble as it likely means the kidneys are doing their job. If you're still concerned, you can discuss this with your doctor. Best of luck.

Most likely: Serum creatinine is affected by the filtering function of your kidneys as well as your muscle mass. In some female patients who are very thin and have low muscle mass, Scr can be quite low.