neotoma: Potions are definitely magical, and not just because of the ingridients. If you combine asphodel and wormwood, you get a highly toxic sludge, so unless Draught of the Living Death is actually Draught of the Poisoned Coma, there is some magic from the brewer transmuting the ingredients into an effective compound.

This is good evidence that there is some magic involved.

Unfortunately, it can't distinguish between the pauraque and neotoma's theory that the magic is imbued in the making, and fernwithy's theory that the magic is imbued in the taking.

We need more data. Preferably all nine combinations of potions made and taken by wizard, squib, and muggle.