Ast is high 120 and alt is normal 48, taking januvia (sitagliptin) , metformin, losartan, simvastatin , fish oil, baby aspirin. why my ast is high &how to lower ast?

Alcohol or diet: There are many causes of an abnormal ast but the most likely is drinking too much alcohol. If the alt were also high then fatty liver caused by overweight would be more likely. There are also rarer additional causes like gallstones, pancreatic disease, viral infection, medication, and immune hepatitis. Best to discuss with your md or a liver specialist.