Why do the people in your life need to know? Are they on meds for physical or mental illness? If so, which meds are they on and what conditions are they for?
That may seem a little brusque, but I guess I'm trying to point out that your health, medical history and current treatment regimen are none of their business. 4 people in real life know that I even have meds, 1 of those is my GP, and the other three wouldn't have a clue which meds and why.
You only need to tell people if you are comfortable with it and feel they need to know. Keeping things "hidden" is different from protecting your privacy.