Typically, these are combinations of vitamins and/or herbal supplements. But the immune system is not like a thermostat that can be turned up or down by a single simple intervention.

Your immune system is complex and involves essentially every organ in your body. Its robustness is a result of your general health practices over long durations. Want to maximize the strength of your immune system?

Then, over years and decades:

–exercise regularly

–don’t smoke

–don’t drink to excess

–maintain a healthy body weight

–get adequate sleep

–eat well—a diet high in fruits and vegetables, low in junk food/fast food

–stay mentally active and socially connected

–get vaccinated per the CDC recommended schedule

That’s it.

None of this is as easy as popping a pill, but there’s good evidence for each of these.

Vitamins? These are at best neutral and not infrequently harmful. Herbal supplements?

Save your money. Good health doesn’t come in a pill. It may be tedious, boring, and lacking pizazz, but the truth is that what doctors advised fifty years ago—get exercise, don’t smoke, etc.—is still valid advice.