Have you seen people you know post on social media about super cheap Plan B One-Step? Seem too good to be true? It might be.

Recently, social media lit up with the news that Amazon.com vendors are selling Plan B One-Step emergency contraception (EC) for on average $24.99—as low as $16.90 plus shipping, and as high as $1,000. On store shelves, this product goes for around $50 a pop, so the apparent price drop is exciting news for those who want to ensure people across the country have access to this form of emergency contraception. But we have to ask: How is that possible?

In 2013, the U.S. Food and Drug Administration (FDA) approved Plan B One-Step, manufactured by Teva Women’s Health, for sale to people of all ages without a prescription and without any point-of-sale restrictions. This means that consumers do not have to go through a pharmacist or physician to obtain the product, but can purchase it directly from store shelves. While the FDA ruled in February of this year that generic emergency contraceptives could be sold on store shelves, only Teva Women’s Health’s authorized generic, Take Action, has appeared on the market. Without competition from other products, the price of Plan B One-Step has remained around $50—though when a prescription is obtained for this otherwise over-the-counter method, it is covered at no cost by health insurance under the Affordable Care Act (ACA).

It is normal for prices to vary from store to store, but such a steep drop in price raises red flags, especially since the wholesale acquisition cost (the cost for wholesalers to purchase the product from the manufacturer, Teva Women’s Health) is estimated to be $32.50 for Plan B One-Step. Wholesalers then sell the product for an estimated $39.00. Therefore, it is highly unlikely that any Amazon.com vendor would be able to acquire Plan B One-Step wholesale and sell it for $16 without taking a substantial financial hit.

After looking into the products on Amazon.com, Reproductive Health Technologies Project (RHTP) found several vendors selling the product. One vendor, Simply Positive Supplements, sells Plan B One-Step under different descriptive names, prices, and manufacturers. In one instance, the manufacturer was listed as Women’s Capital Corporation, which is the trademark holder of Plan B One-Step that was acquired by Barr Pharmaceuticals in 2004. In other instances, it lists the manufacturer as “kwanja shop,” “Neugaugh,” and “superkrit.” Clearly, something is amiss.

Emails and phone calls to Simply Positive Supplements inquiring about its products, supplier, and the discrepancies have gone unreturned.

When RHTP inquired with the seller tarzon about how it was able to sell the product at such a low price and whether it was safe, the seller replied:

I get this at a very discounted rate and the markup in your local pharmacy is a small fortune but due to pricing on amazon we sell it at a lower price.

The seller SuNNy Side UP replied with similar comments, but stated that its product came from “a clinic.” When asked follow-up questions about its suppliers or the clinic it works with, the seller did not respond to RHTP’s emails.

Some clinics may receive Plan B One-Step at a lower cost through the federal government’s 340B Drug Pricing Program to ensure low-income patients have access to various pharmaceutical drugs, but entities that receive drugs under this program “must not resell or otherwise transfer 340B drugs to ineligible patients.” To do so would be considered fraud and a federal crime, and would also limit access to those who need it at low or no cost.

Another vendor, who operates under the name Pharmacy Consultants and sells Plan B One-Step for $16.90, replied to RHTP’s requests stating that he was a licensed pharmacist and was able to sell the product at a deep discount because of a wholesale supplier, although this information is not available on the seller page. When asked about his credentials, the vendor replied that he was a licensed pharmacist in Ohio. He was clear to note that his product “is not from [a] family planning clinic or shop lifted medication.” One review noted that the product’s box arrived opened, the foil encasing the pill was ripped, and the pill was cut in half. After the reviewer notified the seller, he sent her a new package immediately. Another reviewer noted that the product they received was close to being expired.

While we would like to celebrate the arrival of a lower-cost EC, this information gives us some cause for concern.

Plan B One-Step is a single pill taken orally with active contraceptive ingredient levonorgestrel, which works to prevent pregnancy when taken within 72 hours of unprotected sexual intercourse. If what is being sold as Plan B One-Step is actually a placebo or medically inactive pill—or if someone takes half of a pill that arrived split in half, for that matter—then consumers are still at risk of experiencing an unintended pregnancy.

As reproductive health advocates and activists, we first and foremost want to make sure everyone has access to the health care they need and that they obtain what they are actually seeking. Any issue that arises related to EC—a product that serves as the last chance to prevent pregnancy—is too important to go unquestioned. Unfortunately, it appears that some caution is warranted when seeking Plan B from Amazon.com.

It is important to share the information that people seeking EC can obtain Plan B at no cost thanks to the ACA, since all FDA-approved contraceptive methods must be covered without cost sharing (such as a copay or deductible) when prescribed. If insured, someone seeking EC can call their health-care provider and ask them to call in a prescription for ella or another EC product to a local pharmacy. They may also be able to obtain EC directly from a health clinic.

Still, consumers who do not have health insurance and for whom $50 may be unaffordable might be tempted to purchase products that are offered for $16—but they should be wary. Through our research, we could not ascertain how Amazon.com vendors are able to sell Plan B One-Step at a steep discount, or if this product is indeed what the vendors say it is. It behooves us to spread the word about the possibility that what you see might not be what you get. We must do what we can to ensure that people seeking EC obtain what is promised to them—a safe, effective product to prevent pregnancy.

While we certainly hope that market forces lower the price of EC and support expanded access and improved availability, we hope consumers will exercise some caution when seeking this important product.