Ro, the start-up that started out by shipping generic erectile dysfunction medicine, has a far bigger mission in mind.

The company has been quietly opening up pharmacies across the country in an effort to ship the most common generic medications at a flat rate that most Americans can afford. It's now testing a new medication-delivery service with a small number of its users that offers more than 500 generic medications for $5 per medication per month, according to a document seen by CNBC and a source familiar with the company's plans. The $5 price also includes shipping, and the company does not accept insurance. Ro plans to launch the program to everyone in the coming weeks, a person familiar with the company's plans said.

Until recently, pharmacists were banned from informing patients about a more affordable cash price that was available. President Donald Trump has moved to remove those "gag orders," but many pharmacists can still only talk to patients about their options if they're asked. All of that confusion has paved the way for start-ups like Ro and large retailers to offer consumers greater price transparency around their medications. Walmart offers $4 "lowest of" pricing on its website, and private companies like GoodRx offers discount cards to consumers who don't have insurance or have high-deductible plans.

Ro currently offers two brands catering to men and women called Roman and Rory, respectively. It's backed by more than $170 million in capital so far. It offers treatments symptoms like erectile dysfunction, hot flashes or hair loss, and it has doctors that prescribe medications for these patients virtually. Its drug prices will vary, according to the company's website, but the cost of the physician visit is $15.

The new offerings from Ro include some of the most commonly prescribed drugs by U.S. doctors such as Metformin for managing blood sugar, and Atorvastatin, which is routinely prescribed to people with high cholesterol, the document shows.

Ro has said that it does not take insurance, and instead asks consumers to pay out of pocket. That might be more expensive for people with high-quality insurance for some medications. But according to a 2017 New York Times investigation, it can often be cheaper to pay for prescriptions out of pocket.

"Offering the most affordable way to get life-saving medications delivered to your door brings Ro one step closer to our mission of becoming a patient's first call," said the company's CEO Zachariah Reitano, in an emailed statement to confirm the pilot program.

The company currently has three pharmacies it can ship from, which are listed publicly via state pharmacy boards. It is planning to expand to more than 10 by the end of the year, said a person familiar with Ro's plans. That might also make it competitive with Amazon-owned PillPack if the company moves to ship medications overnight and not just on a 30-day cycle.