It was made 1 1/2 months ago, I have been using the same amount, I scooped out the top layer and it did not make a difference, I am not sure if it is losing potency or if I am developing a tolerance to its effects.
Should I double the dose or get a new batch?

Hey there, If the Diltiazem is like mine was it only had a very short shelf life so the efficacy could be decreased or like you said, you could be tolerant, I would try using more first and if that fails get some more if it helps?

I used a bit more this afternoon did not seem to make much of a difference.
Ordered a new batch to be safe, which should only last me about the same time this batch did before it lost potency, it does reach high temps where I have been storing it so no surprise.

I kept mine in the bathroom cabinet, although I was prescribed some Anoheal that had to be kept in the refrigerator, high temps is not good for creams/ointments