Some already cost as liitle as $1 for a 30-day supply, so the benefit of this new program will vary by customer.

Some already cost as liitle as $1 for a 30-day supply, so the benefit of this new program will vary by customer.

The program is limited to Amazon Prime customers.

The program is limited to Amazon Prime customers.

Amazon is adding a prescription drug discount program to its growing health care business.

Amazon is adding a prescription drug discount program to its growing health care business.

The retail giant said Tuesday that it will launch RxPass, a subscription service for customers who have Prime memberships.

The retail giant said Tuesday that it will launch RxPass, a subscription service for customers who have Prime memberships.

Amazon said people will pay $5 a month to fill as many prescriptions as they need from a list of about 50 generic medications, which are generally cheaper versions of brand-name drugs.

The company said the flat fee could cover a list of medications like the antibiotic amoxicillin and the anti-inflammatory drug naproxen.

Sildenafil also made the list. It's used to treat erectile dysfunction under the brand name Viagra and also treats a form of high blood pressure.

Amazon sells a range of generic drugs through its pharmacy service.

Amazon sells a range of generic drugs through its pharmacy service.