How many mg do you need for NMR?

Could you please clarify the context of your question regarding "How many mg do you need for NMR?"? Are you referring to the quantity of a specific sample or compound required for Nuclear Magnetic Resonance (NMR) spectroscopy? NMR is a technique used in chemistry, physics, and biology to study the structure and dynamics of molecules. The amount of sample needed can vary depending on the sensitivity of the NMR instrument, the nature of the sample, and the specific goals of the experiment. If you could provide more details, I would be happy to give a more precise answer.