Erin Bonin, 40, was going through the already stressful process of in vitro fertilization when she learned that one of the medications she needed wasn’t covered by her health insurance. Her South Bend, Ind., pharmacy was charging $733.99 for a one-month supply of the medication, and she needed to take it for three months. A nurse suggested she check GoodRx, a prescription discount and cost-comparison app, for a better price.

She scored a deal there. “Using GoodRx at a pharmacy about 20 minutes from my home would get me the same drug for $30.10,” Bonin says. “I was shocked, but it proves you can find a deal if you are willing to do a little research.”

Millions of people in search of better prices have used GoodRx and similar services, such as Optum Perks, SingleCare and Walgreens’s Prescription Savings Club. The price comparisons and coupons these programs provide can save consumers up to 80 percent, says Ken Malley, senior vice president of Optum, which operates Optum Perks.

Varun Vaidya, a professor at the University of Toledo’s College of Pharmacy and Pharmaceutical Sciences in Ohio, says most consumers have no idea how their prescription medications are priced. A drug may cost pennies to manufacture, but independent or chain pharmacies may pay or be reimbursed different amounts for the same drug. “As with any other product, it’s a free-market system. You could go from store to store and find the same drug costs from $2 to $200,” he says.

That’s where a pharmacy drug savings program can help. Like health insurance companies, these programs negotiate with pharmacies and manufacturers for savings.

“What I like about these programs is the real-time price comparison. Type in the drug name, and instantly see prices at nearby pharmacies,” says Carlene Link, a clinical pharmacist in Ohio. “They have become a valuable tool for consumers dealing with increasing drug prices.”

There is one caveat, though, and it’s a biggie. These services claim not to “sell” your data or collect personal information, but that doesn’t mean they don’t share information with third parties. That’s why you often see ads pop up from drug companies or for related products after you use a service. In fact, following a Consumer Reports investigation, GoodRx gave its users the ability to opt out from cookies or tracking and to request the deletion of all individual user data.

“Discount cards are not insurance or bound by HIPAA, and you may not want stuff shared about yourself, such as anxiety or depression,” says Theresa Tolle, president-elect of the American Pharmacists Association and owner of Bay Street Pharmacy in Sebastian, Fla. “By using an app or online service, you basically enter into a contract with that company, so they can sell or share your personal information. If that bothers you, think twice or find out how to opt out, even if there are some hoops to jump through.”

Want to add a prescription savings card to your health-care tool kit? Here are some things to know.

They’re easy to use. Download the app to your phone or call up the website on your computer. Look up a drug. See the pharmacies nearest to you and their prices. Select the one you like, and get a coupon to present at the pharmacy. You can use your discount instead of your health insurance — or Medicare — if the price is lower. Just remember that, when you use one of these programs, your payment is not applied toward your insurance deductible or out-of-pocket maximum.

They’re best for those without insurance or when a prescription isn’t covered. “More than 90 percent of the time, insurance will be a lower price than the apps,” Malley says. But they can benefit people who are underinsured or have high co-pays for prescriptions, he adds.

Odds are that you can use one at your preferred pharmacy. GoodRx is accepted at more than 70,000 pharmacies nationwide, Optum Perks at more than 64,000 and SingleCare at more than 35,000.

You can save big. Although Bonin’s $700 savings may be atypical, the discounts can be significant. For example: If a consumer is taking a one-milligram lorazepam tablet daily for anxiety, they would typically pay about $24 for a 30-day supply based on the retail price (the price paid by those without insurance), which is set by the local pharmacy. Using Optum Perks, that same consumer could pay about $11 for a 30-day supply at Walgreens, saving approximately $156 a year.

A smartphone is not required. Almost all prescription savings programs can be accessed using a computer. The process for finding the best deal in your area is the same, except you’ll print out the coupon. No computer? No problem. Physical discount cards are also available, either through doctors’ offices or pharmacies. This eliminates your ability to compare drug prices online, but the cards are convenient. Show yours when picking up your medication to see whether there are extra savings.

You may get extra benefits. Walgreens’s Prescription Savings Club costs $20 for individuals and $35 per family annually, but members receive additional perks. These include discounts on medications, including preventive and lifestyle medications (for weight loss, hair loss, etc.) not always covered by insurance; pet medications; and most immunizations. Free one- to two-day delivery is also available for eligible refills. There’s no charge for using SingleCare, and users earn $5 toward filling their next medication at sign-up and another $1 toward filling their next with each prescription filled.

Other companies are getting in on the act. You know something is afoot when both Amazon and Walmart announce prescription discount programs. In June, Walmart Plus members were told they could get select medications at zero cost and thousands of others at up to 85 percent off. Members can use the discount instead of insurance at more than 4,000 Walmart pharmacies. The next day, Amazon started offering common medications, such as those for high blood pressure or diabetes, to Prime members for $1 per month with a six-month supply.

Ask for a price check. Not sure how to get the deepest discount? Ask the pharmacy clerk to compare your insurance coverage with the savings programs. For instance, using CVS’s RX Savings Finder, its pharmacists can view available cost savings for a medication, including what insurance will cover or whether a lower-cost option is available through a third party, such as a savings card.

Pharmacists are savings pros. Navigating the health-care system isn’t easy. If you need help, look to your pharmacist. “We are front-line health providers who value our clients. Don’t be afraid to ask if we have suggestions for saving on your prescription,” Tolle says. If you use a particular pharmacy, see whether it has an in-house program. Many are free or low-cost, and the pharmacy probably won’t sell your information. Tolle’s pharmacy has a discount program that costs $10 per year for a family. Even if your pharmacy has no program, it may be willing to match a discount-card price without using a coupon to eliminate privacy concerns.