Amazon is making its biggest foray in health care with Amazon Pharmacy - its online and mobile prescription medicine business.

The company's move might disrupt the $300 billion pharmacy industry following its PillPack acquisition in 2018.

Amazon Pharmacy will offer generic and branded drugs - including commonly prescribed medications such as insulin, steroid creams and metformin for regulating blood sugar and sumatriptan for migraines, CNBC reports.

The online pharmacy will be accessible to users 18 years old above and in 45 states excluding Minnesota, Kentucky, Hawaii, Louisiana and Illinois. Amazon said it will bring the service to those states later, the report said.

Physicians can send prescriptions straight to Amazon Pharmacy, or patients can transfer prescriptions from retailers like Walgreens Boots Alliance or CVS Health Corp. Amazon won't offer schedule II drugs - including most types of opioids.

According to senior research analyst Tom Forte, Amazon needs to engage in businesses like this to maintain growth. Amazon currently has a market capitalization of more than $1.5 trillion.

The possible effect of Amazon's entry into the pharmaceutical market was immediately felt through the entire sector - the stock prices of Walgreens BA, CVS Health, and Rite Aid all fell Tuesday.

Doug Herrington, Amazon senior vice president for North America, said as more and more people "look to complete everyday errands from home, pharmacy is an important and needed addition to the Amazon online store," he said in a statement.

Amazon's new online pharmacy is expected to open new sources of income for the company, especially as the world health crisis forces consumers to go online for their shopping.

"We wanted to make it easy for consumers to get their medication, understand the cost and get it delivered straight to their homes," TJ Parker, PillPack co-founder and vice president of Amazon Pharmacy, told CNBC.