For muscle building and muscle optimization, I use the following:

• Now capsules for the beta alanine which helps stop the burn in your muscles (you will notice a big difference with this one)
• -creatine monohydrate in powder, micronized 5g/day, from ON which takes a few days to build up (you can take a high loading dose), which is also good for your brain and will allow your muscles more energy when they need it
• L-arginine+l-citrulline, 2-4 caps per day, from Source Naturals,
• Modern BCAA from USP Labs which should be drank while you are working out
• ON whey 30 min before gym and after, plus during the day if you need more protein
• ON Casein protein, which is another type of protein like whey except that it gels up and then takes up to 8 hours to digest so it is great to take at night before bed and sometimes with breakfast so you always have protein available in your body