I got this in the mail today and it inspired me. We got one of these "prescription discount" services about once a week in the pharmacy and, as far as I am aware, they never worked. Never.
First off, if you have regular insurance, your co-pay is probably less than or close to what the discount service will charge you and (since the pharmacy can only use your insurance OR the discount) I would recommend using your insurance so the amount paid applies to your deductible.
Second off, we were able to work with most uninsured customers to: [a] find manufacturer coupons (available on some brand name medications), [b] match the $4 prescription list (which most pharmacies have or match) or [c] contact their doctor to find something less expensive. If an uninsured customer tried the discount service and it sent back a price lower than what we had come up with using those three options it was usually because the discount service was forcing the pharmacy to take a loss (and not a little one). Understandably, most pharmacies will opt to let you go elsewhere over giving away medications for significantly less than they paid.
Third off (if you can read the fine print), the coupon says "15% of profits go to charity." How can something save you money and make a profit? Someone has to pick up the difference and it is either you or the pharmacy or both. It is most definitely NOT the "discount" service.
Please, if you are struggling to pay for your medications, talk to the pharmacist or the pharmacy technician or even your doctor. If they deserve your business they will try to help you.
*I am aware second off and third off aren't real things. I think they should be.