<p>How much medicine did he take? Or
How many medicine did he take? And please provide an explanation.</p>
<p>“Much,” because “many” is usually used to describe an amount that you can’t count, like “how many bacteria…”</p>
<p>Thank You. Anyone else?</p>
<p>It’s much because many describes something that is plural and not singular. I.e: How much turkey did you pick up at the store vs. How many slices of turkey did you pick up</p>
<p>It would be
How much medicine did he take? As in, what was the dosage?
Or
How many medicines did he take? As in, the quantity of different types of medicine.</p>
<p>“How much”-- because medicine cannot be quantified. you cannot count the amount of “medicine” he took. if there is something else involved like a “bottle” of medicine, then you can say how <em>many</em> bottles of medicine.</p>
<p>Yes, what everyone else said- “much” sounds more grammatically correct/is correct! :)</p>
<p>I agree with most of the answers here. “Much” is more appropriately used here for the same reason as @invisiblematters’s.</p>