The Amazon reviews are mostly positive, mostly fairly generic. “This product served its purpose well, and it arrived earlier than expected. The price was far greater than what was available in the local drugstore.”

But the product isn’t a toaster oven or a hardcover book. It’s Plan B, a brand-name emergency contraceptive used to prevent unwanted pregnancy. Amazon has several sellers peddling the birth control option, often for substantially lower prices than local pharmacies charge.

Plan B has been legally available over-the-counter in the U.S. since 2013, but it’s not always easy to find. Some drugstores run out quickly; others have pharmacists that refuse to sell it. Amazon is a well-known national ecommerce site with generally quick shipping and a trusted name, so it certainly appears like Plan B’s presence on the site is a win for reproductive health activists, as well as any woman who can’t find Plan B locally and wants to take it. And the cost of the product on Amazon is substantially cheaper than in drugstores, with sellers peddling the product for $25 on average, which is half the approximately $50 drugstore price.

But it’s too soon to start celebrating more easily available contraceptives. The Plan B on Amazon sounds like it’s too good to be true, because there’s a big catch: Buyers have no way of knowing what they’re getting, and Plan B won’t verify products sold on Amazon. “I called their support online number to verify the lot number of the product. They said as they do not have a relationship with amazon, they refuse to verify the lot number,” one customer wrote. “Use at your own risk I guess…”

Other Plan B buyers note that their packages do not always come in pristine condition. “Upon arrival, I opened the packaging to make sure that these were legit—I mean I got them for a really good price (roughly $18 each) so I had to check. Good thing I did! I noticed that one of them had been tampered with. The box was open and the foil that protects the pill was open AND on top of that, the pill was cut in half,” a customer wrote.

The vendor gave her a new, untampered package for free, so she was satisfied. But for emergency contraceptives, time is of the essence, and if someone receives half a pill and they have a small window to take it effectively, that kind of screw-up could have consequences nine months later.

We spoke to Pharmacy Consultants, one of the most popular vendors, who sells the product for $16.90. A representive insisted on his product’s quality, and said he priced it so low to stay competitive. He also, ironically, warned online shoppers of the perils of buying from an unvetted source.

“As a pharmacist, I control the quality of my product. I want my customers to know this. Recently counterfeit Alli was being sold online that actually contained a banned ingredient. The buyer must be careful who they buy from,” he said.

While most of the reviews for Pharmacy Consultants and other vendors are positive, researchers at Reproductive Health Reality Check looked at the merchants and could not confirm that they were selling legitimate products—and they noted that some vendors put down gibberish under the manufacturer section.

RHRC pointed out that the wholesale acquisition cost of Plan B is thought to be around $32, so the low prices on Amazon may be an indication something is amiss. While the vendors could have received the drugs from clinics that receive Pla B at a lower cost due to a government pricing program to help lower-income people, reselling them online would be fraud.

For women who want to order an emergency contraceptive online but want a surer thing than Amazon’s unverified merchants, there is another option: KwikMed. Despite its quacky-sounding name, KwikMed is a recognized online medical merchant that only sells medicine directly from pharmaceutical companies, including emergency contraceptive ella.

Unlike Amazon’s emergency contraceptives, the product is vetted. “Many online merchants, including Amazon, sell medications with no traceable pedigree and which are likely counterfeit and potentially dangerous. There is a serious problem with counterfeits online for nearly every medication – whether prescription or over the counter,” Emily Murray, a communications specialist at KwikMed, told us. “By purchasing from KwikMed, consumers can be sure they are purchasing safe, licensed, properly manufactured medications.”

Access to low-cost birth control is a cornerstone of reproductive health. Rolling the dice with the Amazon vendors can save money and avoid embarrassment at the local pharmacy, but there’s no way of verifying that it’s really the right pills in the box, or that they’ve been obtained legally. Amazon did not return our request for information about its Plan B sales, but the retailer should establish itself as a reproductive health ally. If it developed a verification process for vendors like this, making it truly safe to buy the drugs online, it would be a huge win for women.

Until then, use Amazon for watching HBO, not buying contraceptives.

H/T The Toast | Photo by JuditK/Flickr (CC BY ND 2.0)